Category: Lab Lessons

NEDADI or ‘Nee Daddy’ another treatment target beyond NEDA

Prof G do you think disability improvement is a reasonable treatment goal?

NEDADI = no evident disease activity and disability improvement

Two weeks ago one of my patients with PPMS, who we treated with off-label subcutaneous cladribine, came for her annual follow-up appointment. Despite being treated with cladribine over 2 years ago she has unfortunately progressed from EDSS 5.5 to 6.5. Her latest MRI brain did not show any new T2 lesions. She asked why we hadn’t scanned her spinal cord. She is desperate for us to find some disease activity so that she can be retreated or preferably offered ocrelizumab. She has a well-off family member who is prepared to cover the costs of ocrelizumab treatment privately. What should I do?

As you know I don’t support private prescribing in the NHS as it undermines the NHS’ founding principles; free at the point of access and equity. However, it is difficult to say no to private prescribing if a patient insists, particularly as there is now a mechanism to do this under the NHS. I am also first a doctor looking after the individual patient and this takes priority over my duty as an NHS employee and guardian of its socialist healthcare ideals.

I didn’t agree to a private prescription for ocrelizumab. Instead, I batted the problem into the long grass and agreed to bring her via our planned investigation unit for an MRI of the spine and lumbar puncture to measure CSF neurofilament levels. If there are new spinal cord lesions and/or a raised CSF neurofilament level then we could potentially look at an additional course of cladribine, off-label rituximab under the NHS, private ocrelizumab or possible recruitment into a clinical trial. I suspect that the MRI will show no new lesions and the CSF NFL levels will be normal. If this is the case then she has NEDA with worsening disability. I did refer her to my blog post on this issue (EXPLAINING WHY YOU GET WORSE DESPITE BEING NEDA) so she could get some understanding of what was happening to her.

During the consultation, she asked me ‘why a friend’s daughter with very bad MS, who had been treated with alemtuzumab, had made such a remarkable recovery?’ Apparently, this young woman had been rendered partially paraplegic from a spinal relapse and after alemtuzumab had recovered function and was now walking almost ‘normally’ again. My patient wanted to know why there was such a difference between herself, someone with PPMS, and her friend’s daughter a young woman with highly-active RRMS.

You may remember the other day I asked you to guess why I was so impressed with the HSCT-MIST trial. Let me try and explain why.

Should we be changing our expectations of what DMTs can offer pwMS? Are we entering an era when the expectation of disability improvement becomes the norm? I certainly hope so.

The most impressive aspect of the recent HSCT-MIST trial was not the NEDA data or the improved safety of HSCT, which are obviously important, but the disability improvement data. During the first year post-HSCT the mean EDSS scores improved from 3.4 to 2.4 vs. a worsening from 3.3 to 4.0 in those on the basket of licensed DMTs. Is this unique to HSCT? How does this HSCT data compare to other treatment options?

The first DMT to show a convincing impact on disability improvement in a phase 3 controlled trial was with natalizumab in the AFFIRM study; at 2 years the probability of a sustained improvement in disability was 30% for natalizumab-treated patients and 19% for patients who received placebo.

Phillips  et al. Sustained improvement in Expanded Disability Status Scale as a new efficacy measure of neurological change in multiple sclerosis: treatment effects with natalizumab in patients with relapsing multiple sclerosis. Mult Scler. 2011 Aug;17(8):970-9.

The next convincing phase 3 result was with alemtuzumab-treated patients in the CARE-MS2 trial; alemtuzumab-treated patients were more than twice as likely as IFN-β-1a-treated patients to experience 3-month confirmed disability improvement (35% vs 19%).

Giovannoni et al. Alemtuzumab improves preexisting disability in active relapsing-remitting MS patients. Neurology. 2016 Nov 8;87(19):1985-1992.

Unfortunately, the latest HSCT trial did not report their disability improvement data as confirmed or sustained disability improvement at 3 months. The main reason for this was methodological in that patients patients on DMTs had a rescue option of being treated with HSCT. However, in the first 12 months, 12/55 (22%) of patients on DMTs compared to 38/55 (69%) who were treated with HSCT had an improvement in their EDSS. Based on the final data set I suspect that in a large proportion of the HSCT patients the improvements were sustained.

Burt et al.  Effect of Nonmyeloablative Hematopoietic Stem Cell Transplantation vs Continued Disease-Modifying Therapy on Disease Progression in Patients With Relapsing-Remitting Multiple Sclerosis: A Randomized Clinical Trial. JAMA. 2019 Jan 15;321(2):165-174.

What about the new kids on the block, i.e. ocrelizumab and cladribine? Unfortunately, we don’t have published data on cladribine, but I will try and rectify this and will ask for the analysis to be done. However, the phase 3 pooled OPERA data of ocrelizumab has been published; 21% of ocrelizumab-treated patients had disability improvement confirmed after at least 12 weeks compared to only 16% of  IFN-β-1a-treated patients.

Hauser et al. Ocrelizumab versus Interferon Beta-1a in Relapsing Multiple Sclerosis. N Engl J Med. 2017 Jan 19;376(3):221-234.

So the league table for disability improvement of HSCT over alemtuzumab, over natalizumab, followed by ocrelizumab seems to mirror the brain atrophy or end-organ damage data. Are you surprised? I am not. A large driver of disability improvement is reserve capacity, i.e. brain reserve or put simply the size of your brain, which predicts and provides the substrate for recovery. This is another reason why you would want your MS treated early and just maybe you would want to flip the pyramid and go for the DMTs that offer you the best chance of disability improvement.

Hidden in this data may be a clue about the pathogenesis of MS. What differentiates HSCT and alemtuzumab from natalizumab and then from ocrelizumab? Could it be the transient depletion and reconstitution of the T-cell compartment?

Joanne Jones and her colleagues from Cambridge showed that among trial participants with no clinical disease activity immediately before treatment, or any clinical or radiological disease activity on-trial, disability improved after alemtuzumab but not following interferon β-1a. They suggested that this disability improvement after alemtuzumab could not be attributable to its anti-inflammatory effects and suggested that T lymphocytes, reconstituting after alemtuzumab, permit or promote brain repair via the production of growth factors in particular brain-derived neurotrophic factor (BDNF),  platelet-derived growth factor (PDGF) and ciliary neurotrophic factor (CNTF). If their hypothesis holds out then this may be another reason why NIRTs (non-selective immune reconstitution therapies) outperform SIRTs (selective immune reconstitution therapies) in going beyond NEDA, i.e NEDADI. And just maybe you need these cells to traffic to the central nervous system to deliver these growth factors.

Jones et al. Improvement in disability after alemtuzumab treatment of multiple sclerosis is associated with neuroprotective autoimmunity. Brain. 2010 Aug;133(Pt 8):2232-47.

Another piece of the puzzle is the positive effect alemtuzumab has on the MRI metric called magnetization transfer ratio or MTR, which is a measure of tissue integrity. In a small study, the mean MTR fell in 18 untreated MSers in normal-appearing grey and white matter. Conversely, mean MTR was stable in 20 alemtuzumab-treated MSers, which suggests alemtuzumab protects against tissue damage. This MTR data mirrors the clinical observations and is congruent with some of the basic science. Wouldn’t it be nice to do an experiment of using natalizumab post-alemtuzumab to see if by blocking T-cell trafficking we blunt the alemtuzumab-associated improvement in disability, i.e. to test whether T-cell trafficking is required to drive repair mechanisms?

Button et al. Magnetization transfer imaging in multiple sclerosis treated with alemtuzumab.  Mult Scler. 2013 Feb;19(2):241-4.

So what do I tell my patient? Do I tell her that the reason why she has not improved is that she is older, has more advanced MS and hence less reserve capacity to allow disability improvement? Or that we may not have tackled the root cause of her MS with subcutaneous cladribine? I stuck to the former explanation as the latter is simply a hypothesis that needs more thinking, more debate and some new experiments to establish if the treatment hierarchy in relation to end-organ damage and disability improvement is based on the different modes of action of our DMTs.

Despite the reasons behind these observations we are now entering an era were disability improvement is not an unreasonable expectation for pwMS, provided they are treated early and with high-efficacy DMTs.

How many you have been told about disability improvement on DMTs?

CoI: multiple, please note that I am a co-author on the natalizumab, alemtuzumab and ocrelizumab disability improvement papers.

The Learner

Do we need to include cognition as a treatment target in multiple sclerosis?

In every clinic, I do patients with MS complain of cognitive symptoms. Either it is increasing forgetfulness, difficult multi-tasking, the inability to learn and use a new technology or cognitive fatigue.

Case study: One of my high functioning patients, who worked in a large City law firm, simply could not keep up and was recently forced to take early retirement because of her MS. She had been interferon-beta-1b for 12 years but had stopped treatment about 7 years ago when she had moved to London. Her MRI showed a highish lesion load and severe brain atrophy. She had had a few relapses on interferon-beta in the early years, but her neurologist decided to leave her on interferon-beta. Back then this was normal practice; we didn’t expect interferon-beta to render you relapse-free. Interferons were only meant to reduced attack rates by about a third and severe attacks, i.e. those requiring steroids and/or hospital admission, by about a half. The only alternative when this patient was having relapses on interferon-beta was glatiramer acetate; please remember this was pre-natalizumab era. Apart from her cognitive problems, this patient had mild unsteadiness of gait, but this had not affected her walking distance and she was still able to do yoga several times per week. To help with her unemployment insurance claim I requested a formal neuropsychological assessment and she was documented to have profound cognitive deficits across multiple domains. The conclusion based on these tests was that she would never be able to have meaningful employment again; at least not in the knowledge economy When I took a detailed history it was clear that she had had progressive cognitive impairment over at least 7-10 years. In other words, she had secondary progressive MS manifesting as progressive dementia.

You must not underestimate the impact MS has on cognition. Cognitive problems can be there from the start; approximately a quarter of people with a radiologically isolated syndrome (RIS) or asymptomatic MS already have cognitive impairment. The proportion with cognitive impairment just gets higher the longer you have the disease. What is driving cognitive impairment is almost certainly grey matter pathology, both in the cortex and deep grey matter, which is not detected with our current monitoring tools.

In the analysis below, of the pivotal phase 3 fingolimod trials, we showed that not being able to improve on the Paced Auditory Serial Addition Test (PASAT) at baseline predicted a worse outcome. The PASAT is a very sensitive cognitive test that used to part of the battery we called the MS Functional Composite (MSFC). The PASAT is not very nice to do and has now been replaced by the SDMT (symbol digital modality test).

When you start doing cognitive screening tests such as the PASAT and SDMT you tend to improve the scores due to a learning effect. We hypothesised that pwMS who couldn’t learn i.e. were unable to improve their PASAT scores at baseline would do worse. This is exactly what we found and we noted it regardless of treatment allocation; i.e. whether you were on fingolimod or placebo. Poor learners were older, had a higher disability score at baseline, smaller brains and higher lesions volumes on MRI; i.e. they had reduced cognitive reserve. The depressing point about this analysis was that even the poor learners on fingolimod did badly; it was if they were already primed to do badly and that starting a DMT had a limited impact on the outcome. Active MS in the past had primed their brains to continue deteriorating; previous damage or a new type of MS lesion, possibly SELs (slowly expanding lesions) was driving their worsening.

The message here is that it is very important to prevent the ravages of MS by treating as early and effectively as possible. In some pwMS, this is easy because you present early before too much damage has accrued. In others, you may have longer asymptomatic periods during which you have already acquired a lot of damage. Regardless of what group you are in, you need to seriously consider getting on top of your MS disease activity as soon as possible to prevent further damage.

It is clear from the Sormani meta-analysis (article 2 below) that you do best on DMTs that have the greatest impact on inflammatory activity (new MRI lesions) and those that reduce brain volume loss the most. This is why flipping the pyramid and going for the most effective DMTs first-line is a very appealing treatment strategy; particularly those that ‘normalise’ brain volume loss.

This study also raises the question about whether or not we should be monitoring cognition in routine clinical practice? This topic is a hot potato and gets discussed and debated all the time. At the moment I think most neurologists don’t agree with doing routine cognitive testing, because of the lack of evidence in terms of treatments that impact on cognition. This, however, may change when siponimod gets licensed. It is clear in the siponimod trial that siponimod delayed cognitive worsening compared to placebo. The following is the siponimod data that was presented at the AAN and EAN last year.

I believe that everyone with MS should have the option of monitoring their own cognition. If your cognition is improving and/or is stable that is good news. If, however, cognition is worsening then a frank discussion needs to be had about why it is getting worse and can anything be done about it. There are many reasons why pwMS may have worsening cognition and some of these are treatable. This is why we have developed an online cognitive test, which we are currently validating, to allow self-monitoring of cognition. If you had access to the test would you use it?

Article 1

Sormani et al. Learning ability correlates with brain atrophy and disability progression in RRMS. J Neurol Neurosurg Psychiatry. 2019 Jan;90(1):38-43.

OBJECTIVE: To assess the prognostic value of practice effect on Paced Auditory Serial Addition Test (PASAT) in multiple sclerosis.

METHODS: We compared screening (day -14) and baseline (day 0) PASAT scores of 1009 patients from the FTY720 Research Evaluating Effects of Daily Oral therapy in Multiple Sclerosis (FREEDOMS) trial. We grouped patients into high and low learners if their PASAT score change was above or below the median change in their screening PASAT quartile group. We used Wilcoxon test to compare baseline disease characteristics between high and low learners, and multiple regression models to assess the respective impact of learning ability, baseline normalised brain volume and treatment on brain volume loss and 6-month confirmed disability progression over 2 years.

RESULTS: The mean PASAT score at screening was 45.38, increasing on average by 3.18 from day -14 to day 0. High learners were younger (p=0.003), had lower Expanded Disability Status Scale score (p=0.031), higher brain volume (p<0.001) and lower T2 lesion volume (p=0.009) at baseline. Learning status was not significantly associated with disability progression (HR=0.953, p=0.779), when adjusting for baseline normalised brain volume, screening PASAT score and treatment arm. However, the effect of fingolimod on disability progression was more pronounced in high learners (HR=0.396, p<0.001) than in low learners (HR=0.798, p=0.351; p for interaction=0.05). Brain volume loss at month 24 tended to be higher in low learners (0.17%, p=0.058), after adjusting for the same covariates.

CONCLUSIONS: Short-term practice effects on PASAT are related to brain volume, disease severity and age and have clinically meaningful prognostic implications. High learners benefited more from fingolimod treatment.

Article 2

Sormani et al. Treatment effect on brain atrophy correlates with treatment effect on disability in multiple sclerosis. Ann Neurol. 2014 Jan;75(1):43-9.

OBJECTIVE: To evaluate the extent to which treatment effect on brain atrophy is able to mediate, at the trial level, the treatment effect on disability progression in relapsing-remitting multiple sclerosis (RRMS).

METHODS: We collected all published randomized clinical trials in RRMS lasting at least 2 years and including as endpoints disability progression (defined as 6 or 3 months confirmed 1-point increase on the Expanded Disability Status Scale), active magnetic resonance imaging (MRI) lesions (defined as new/enlarging T2 lesions), and brain atrophy (defined as change in brain volume between month 24 and month 6-12). Treatment effects were expressed as relative reductions. A linear regression, weighted for trial size and duration, was used to assess the relationship between the treatment effects on MRI markers and on disability progression.

RESULTS: Thirteen trials including >13,500 RRMS patients were included in the meta-analysis. Treatment effects on disability progression were correlated with treatment effects both on brain atrophy (R(2)  = 0.48, p = 0.001) and on active MRI lesions (R(2)  = 0.61, p < 0.001). When the effects on both MRI endpoints were included in a multivariate model, the correlation was higher (R(2)  = 0.75, p < 0.001), and both variables were retained as independently related to the treatment effect on disability progression.

INTERPRETATION: In RRMS, the treatment effect on brain atrophy is correlated with the effect on disability progression over 2 years. This effect is independent of the effect of active MRI lesions on disability; the 2 MRI measures predict the treatment effect on disability more closely when used in combination.

CoI: multiple

Beyond NEDA

Prof G are we being lulled into a false sense of security by being told that we have no evident disease activity (NEDA)?

A patient of mine, who I have been looking after now for over 11 years, asked me in clinic a few weeks ago why despite being NEDA for 6 years, on a highly effective maintenance DMT (fingolimod), has she gone from being able to run 5-10 km to needing a stick and barely managing to walk from the Whitechapel Underground Station to my clinic (~200m), without having to stop and rest?

What this patient doesn’t know, despite no new visible T2 lesions, is that she has developed obvious, to the naked eye, progressive brain atrophy.  This particular patient prompted me to write a few blog posts to try and explain what is happening to her brain. Before reading the remainder of this post you may want to read the following posts:

An important question in relation to this patient is why do some DMTs have such a profound impact on end-organ damage markers, in particular, brain volume loss and others do not? Not all DMTs are made equal when it comes to preventing, or slowing down, brain volume loss.

At the top of the league table are alemtuzumab and HSCT (~0.2-0.25% loss per annum). Both these treatments are NIRTs (non-selective immune reconstitution therapies). Natalizumab is next with an annual brain volume loss in region of 0.25-0.30% per annum. Ocrelizumab (anti-CD20) comes fourth with a rate of brain volume loss of ~0.30-0.35% per annum. Fingolimod 5th at ~0.4% per annum. Cladribine has a rate of loss of brain volume of ~0.55% per annum with the other runs after that.

For me, the disappointment are the anti-B cell therapies, ocrelizumab and cladribine. Despite these DMTs being very effective at switching off new focal inflammatory lesions (relapses and new T2 and Gd-enhancing lesions) their impact on end-organ damage is only moderate. These observations have convinced me more than ever that focal inflammation is not MS, but simply the immune system’s response to what is causing MS. The latter hypothesis is what I have been presenting as part of my ‘Field Hypothesis’ for several years on this blog.

What these observations are telling me is that peripheral B-cells are a very important part of the immune response to the cause of MS, but they are not necessarily involved in driving the true pathology, which is causing the progressive brain volume loss. The caveat to this is that anti-CD20 therapies and cladribine may not be eliminating the B-cells and plasma cells within the CNS, which is why we need add-on treatments to try and scrub the brain free of these cells to see if the brain atrophy rate ‘normalises’. This is why we are starting a safety study this year of an add-on myeloma drug to target the CNS B-cell and plasma cell response to test this hypothesis.

What does this mean for the average person with MS? Firstly, you may not want to dismiss alemtuzumab and HSCT as a treatment option. These NIRTS differ from anti-CD20 therapies and cladribine in that they target both B and T cells. We may need to target both these cells types to really get on top of MS. I am aware of the appeal of anti-CD20 therapies and cladribine; they are safer and easier to use because of less monitoring, however, this may come at a cost in the long-term. The SIRTs (selective IRTs) may not be as good as the NEDA data suggests. Please remember that once you have lost brain you can’t get it back.

The tradeoff with alemtuzumab and HSCT is the frontloading of risk to get the greatest efficacy over time. Choosing a DMT on a rung or two down on the therapeutic ladder gives you better short-term safety and makes the lives of your MS team easier, because of less monitoring, but at a potential long-term cost to your brain and spinal cord.  This is why to make an informed decision about which DMT you choose is a very complicated process and subject to subtle and often hidden effects of cognitive biases. The one bias I am very aware of is the ‘Gambler’s Dilemma’, be careful not to be lulled into a false sense of security by your beliefs; most gamblers lose.

Over the last few years you may have seen a theme developing in my thinking as we move the goalposts in terms of our treatment target beyond NEDA-3 to target end-organ damage, i.e. brain volume loss, T1 black holes, the slowly expanding lesions (SELs), neurofilament levels, cognition, sickness behaviour, OCBs, etc. Our treatment aim should be to ‘Maximise Brain Health’ across your life and not just the next decade. Please stop and think!

When I was preparing this post I dropped Prof. Doug Arnold an email about the impact of alemtuzumab and HSCT on the slowly expanding lesion or SEL. Unfortunately, these analyses have not been done despite good trial data sets being available for analysis. He said it was a resource issue; i.e. a euphemism for money and permission to do the analyses. For me, these questions are the most important ones to answer in 2019. Wouldn’t you want to know if alemtuzumab and HSCT were able to switch off those destructive SELs in your brain? Knowing this may impact your decision to go for the most effective DMTs; frontloading risk to maximise outcomes in the long term.

What should I advise my patient; to stay on fingolimod or to escalate to a more effective DMT?

The following articles are the important ones for you to read or at least be aware of:

Article 1

Lee et al. Brain atrophy after bone marrow transplantation for treatment of multiple sclerosis. Mult Scler. 2017 Mar;23(3):420-431.

BACKGROUND:  A cohort of patients with poor-prognosis multiple sclerosis (MS) underwent chemotherapy-based immune ablation followed by immune reconstitution with an autologous hematopoietic stem cell transplant (IA/aHSCT). This eliminated new focal inflammatory activity, but resulted in early acceleration of brain atrophy.

OBJECTIVE: We modeled the time course of whole-brain volume in 19 patients to identify the baseline predictors of atrophy and to estimate the average rate of atrophy after IA/aHSCT.

METHODS: Percentage whole-brain volume changes were calculated between the baseline and follow-up magnetic resonance imaging (MRI; mean duration: 5 years). A mixed-effects model was applied using two predictors: total busulfan dose and baseline volume of T1-weighted white-matter lesions.

RESULTS: Treatment was followed by accelerated whole-brain volume loss averaging 3.3%. Both the busulfan dose and the baseline lesion volume were significant predictors. The atrophy slowed progressively over approximately 2.5 years. There was no evidence that resolution of edema contributed to volume loss. The mean rate of long-term atrophy was -0.23% per year, consistent with the rate expected from normal aging.

CONCLUSION: Following IA/aHSCT, MS patients showed accelerated whole-brain atrophy that was likely associated with treatment-related toxicity and degeneration of “committed” tissues. Atrophy eventually slowed to that expected from normal aging, suggesting that stopping inflammatory activity in MS can reduce secondary degeneration and atrophy.

Article 2

Arnold et al. Superior MRI outcomes with alemtuzumab compared with subcutaneous interferon β-1a in MS. Neurology. 2016 Oct 4;87(14):1464-1472.Neurology. 2016 Oct 4;87(14):1464-1472.

OBJECTIVE: To describe detailed MRI results from 2 head-to-head phase III trials, Comparison of Alemtuzumab and Rebif Efficacy in Multiple Sclerosis Study I (CARE-MS I; NCT00530348) and Study II (CARE-MS II; NCT00548405), of alemtuzumab vs subcutaneous interferon β-1a (SC IFN-β-1a) in patients with active relapsing-remitting multiple sclerosis (RRMS).

METHODS: The impact of alemtuzumab 12 mg vs SC IFN-β-1a 44 μg on MRI measures was evaluated in patients with RRMS who were treatment-naive (CARE-MS I) or who had an inadequate response, defined as at least one relapse, to prior therapy (CARE-MS II).

RESULTS: Both treatments prevented T2-hyperintense lesion volume increases from baseline. Alemtuzumab was more effective than SC IFN-β-1a on most lesion-based endpoints in both studies (p < 0.05), including decreased risk of new/enlarging T2 lesions over 2 years and gadolinium-enhancing lesions at year 2. Reduced risk of new T1 lesions (p < 0.0001) and gadolinium-enhancing lesion conversion to T1-hypointense black holes (p = 0.0078) were observed with alemtuzumab vs SC IFN-β-1a in CARE-MS II. Alemtuzumab slowed brain volume loss over 2 years in CARE-MS I (p < 0.0001) and II (p = 0.012) vs SC IFN-β-1a.

CONCLUSIONS: Alemtuzumab demonstrated greater efficacy than SC IFN-β-1a on MRI endpoints in active RRMS. The superiority of alemtuzumab was more prominent during the second year of both studies. These findings complement the superior clinical efficacy of alemtuzumab over SC IFN-β-1a in RRMS.

CLINICALTRIALSGOV IDENTIFIER: NCT00530348 and NCT00548405.

CLASSIFICATION OF EVIDENCE: The results reported here provide Class I evidence that, for patients with active RRMS, alemtuzumab is superior to SC IFN-β-1a on multiple MRI endpoints.

Article 3

Vavasour et al. A 24-month advanced magnetic resonance imaging study of multiple sclerosis patients treated with alemtuzumab. Mult Scler. 2018 Apr 1:1352458518770085. doi: 10.1177/1352458518770085.

BACKGROUND: Tissue damage in both multiple sclerosis (MS) lesions and normal-appearing white matter (NAWM) are important contributors to disability and progression. Specific aspects of MS pathology can be measured using advanced imaging. Alemtuzumab is a humanised monoclonal antibody targeting CD52 developed for MS treatment.

OBJECTIVE: To investigate changes over 2 years of advanced magnetic resonance (MR) metrics in lesions and NAWM of MS patients treated with alemtuzumab.

METHODS: A total of 42 relapsing-remitting alemtuzumab-treated MS subjects were scanned for 2 years at 3 T. T1 relaxation, T2relaxation, diffusion tensor, MR spectroscopy and volumetric sequences were performed. Mean T1 and myelin water fraction (MWF) were determined for stable lesions, new lesions and NAWM. Fractional anisotropy was calculated for the corpus callosum (CC) and N-acetylaspartate (NAA) concentration was determined from a large NAWM voxel. Brain parenchymal fraction (BPF), cortical thickness and CC area were also calculated.

RESULTS: No change in any MR measurement was found in lesions or NAWM over 24 months. BPF, cortical thickness and CC area all showed decreases in the first year followed by stability in the second year.

CONCLUSION: Advanced MR biomarkers of myelin (MWF) and neuron/axons (NAA) show no change in NAWM over 24 months in alemtuzumab-treated MS participants.

CoI: multiple

What is happening to my cortex?

A very common analogy is the comparison of MS to an iceberg. Why?

Only one-eighth of an iceberg is visible above the water; to see what is below the water line requires specialised technology. The MS iceberg analogy refers to several observations:

1. For each clinical relapse, 10 or more MRI visible lesions are seen on MRI.
2. For each visible white matter lesions on MRI, there are at least an equivalent number or more grey matter lesions. In fact, it is now estimated that more than half the MS pathology is in the grey matter.
3. For every visible white matter lesion, either on MRI or with the naked eye, there are 20 or more microscopic lesions present in the white matter.
4. Despite only a relatively small amount of brain or spinal cord atrophy, there is almost three times as much neuronal loss underlying the atrophy.
5. Despite a relatively good recovery of function in a particular pathway, for example, after a relapse, there is a substantial loss of axons and hence reserve capacity in that pathway.
6. People with MS have many more hidden symptoms and disabilities than visible physical disabilities; early MS is often a hidden disease.

When you use newer technologies, for example, a 7 Tesla MRI to look at cortical or grey matter lesions in MS you begin to see how large the iceberg really is. Please remember the vast majority of cortical MS lesions (>90%) or not seen with conventional MRI. The bad news in the study below is that almost all the pwMS studied had cortical lesions and these, not surprisingly, correlated with disability and cognitive impairment. What is interesting is that the lesions on the surface of the brain (subpial), but not those on the grey-white matter interface (leukocortical), correlated better with cortical volume. However, the grey-white matter interface, or leukocortical, lesions correlated most strongly with cognitive impairment.  

What is becoming increasingly important is to try and target the grey matter pathology and prevent cognitive impairment in pwMS. The problem is we don’t routinely monitor brain and in particular grey matter atrophy in routine clinical practice; in fact it is largely ignored. If we did we would probably find many more pwMS opting for the higher efficacy treatments that have the greatest impact on brain atrophy (alemtuzumab and HSCT).

It is important for you to realise that you can be NEDA-3, i.e. no clinical attacks and MRI activity, and still have progressive grey matter atrophy. Why this is happening is debatable. Some evidence points to immunoglobulins and complement activation, rather than cytotoxic T-cells, being the major driver of cortical pathology. This why Barts-MS is exploring add-on drugs that will hopefully target the B-cell follicles and plasma cells within the central nervous system to try and slow down this process. We plan to start recruiting for our add-on study later this year.

I have little doubt that slowing down and preventing progressive brain and grey matter atrophy will become one of the treatment targets for the next generation of MSologists. To make this a reality we need to have tools to measure these processes reliably in clinical practice.

Harrison et al. Association of Cortical Lesion Burden on 7-T Magnetic Resonance Imaging With Cognition and Disability in Multiple Sclerosis. JAMA Neurol. 2015 Jul 20. doi: 10.1001/jamaneurol.2015.1241.

IMPORTANCE: Cortical lesions (CLs) contribute to physical and cognitive disability in multiple sclerosis (MS). Accurate methods for visualization of CLs are necessary for future clinical studies and therapeutic trials in MS.

OBJECTIVE: To evaluate the clinical relevance of measures of CL burden derived from high-field magnetic resonance imaging (MRI) in MS.

DESIGN, SETTING, AND PARTICIPANTS: An observational clinical imaging study was conducted at an academic MS center. Participants included 36 individuals with MS (30 relapsing-remitting, 6 secondary or primary progressive) and 15 healthy individuals serving as controls. The study was conducted from March 10, 2010, to November 23, 2012, and analysis was performed from June 1, 2011, to September 30, 2014. Seven-Tesla MRI of the brain was performed with 0.5-mm isotropic resolution magnetization-prepared rapid acquisition gradient echo (MPRAGE) and whole-brain, 3-dimensional, 1.0-mm isotropic resolution magnetization-prepared, fluid-attenuated inversion recovery (MPFLAIR). Cortical lesions, seen as hypointensities on MPRAGE, were manually segmented. Lesions were classified as leukocortical, intracortical, or subpial. Images were segmented using the Lesion-TOADS (Topology-Preserving Anatomical Segmentation) algorithm, and brain structure volumes and white matter (WM) lesion volume were reported. Volumes were normalized to intracranial volume.

MAIN OUTCOMES AND MEASURES: Physical disability was measured by the Expanded Disability Status Scale (EDSS). Cognitive disability was measured with the Minimal Assessment of Cognitive Function in MS battery.

RESULTS: Cortical lesions were noted in 35 of 36 participants (97%), with a median of 16 lesions per participant (range, 0-99). Leukocortical lesion volume correlated with WM lesion volume (ρ = 0.50; P = .003) but not with cortical volume; subpial lesion volume inversely correlated with cortical volume (ρ = -0.36; P = .04) but not with WM lesion volume. Total CL count and volume, measured as median (range), were significantly increased in participants with EDSS scores of 5.0 or more vs those with scores less than 5.0 (count: 29 [11-99] vs 13 [0-51]; volume: 2.81 × 10-4 [1.30 × 10-4 to 7.90 × 10-4] vs 1.50 × 10-4 [0 to 1.01 × 10-3]) and in cognitively impaired vs unimpaired individuals (count: 21 [0-99] vs 13 [1-54]; volume: 3.51 × 10-4 [0 to 1.01 × 10-4] vs 1.19 × 10-4 [0 to 7.17 × 10-4]). Cortical lesion volume correlated with EDSS scores more robustly than did WM lesion volume (ρ = 0.59 vs 0.36). Increasing log[CL volume] conferred a 3-fold increase in the odds of cognitive impairment (odds ratio [OR], 3.36; 95% CI, 1.07-10.59; P = .04) after adjustment for age and sex and a 14-fold increase in odds after adjustment for WM lesion volume and atrophy (OR, 14.26; 95% CI, 1.06-192.37; P = .045). Leukocortical lesions had the greatest effect on cognition (OR for log [leukocortical lesion volume], 9.65; 95% CI, 1.70-54.59, P = .01).

CONCLUSIONS AND RELEVANCE: This study provides in vivo evidence that CLs are associated with cognitive and physical disability in MS and that leukocortical and subpial lesion subtypes have differing clinical relevance. Quantitative assessments of CL burden on high-field MRI may further our understanding of the development of disability and progression in MS and lead to more effective treatments.

CoI: multiple

To T or not to T (2)

Prof G what happens to MS disease activity if you stimulate T-cells?

About 2 years ago I attended a grand round during which a patient with a history of RRMS had had a catastrophic relapse after receiving ipilimumab for metastatic melanoma. The patient has a massive brain stem relapse and her MRI showed multiple Gd-enhancing lesions with several pseudotumoral lesions. She was in a bad way. Interestingly, this case was not unique as a very similar case had been published. In addition, there are series of other examples of ipilimumab and other immune checkpoint inhibitors exacerbating and/or triggering autoimmune diseases including an MS-like disease. I say MS-like because we don’t know for sure if these cases will turn out to have classic MS on biopsy, or at post-mortem, to prove they have definite MS according to a conventional definition of the disease.

Ipilimumab belongs to the class of drugs called ‘checkpoint inhibitors’ that are designed to remove one of the immunological brakes that control T-cell activation. Ipilimumab is one of many T-cell stimulants that have revolutionised the care of patients with various different cancers. Ipilimumab is a very smart drug it blocks CTLA-4, a cell surface molecule on T cells, which normally blocks or downregulates T cell activation when it binds to CD80 and CD86 on antigen-presenting cells. Ipilimumab enhances the anti-tumoral response while increasing the likelihood of autoimmunity.

So what has this really got to do with MS? Well, these cases are telling us in a not so subtle way that by stimulating T-cells we can exacerbate MS. In other words, T-cells are probably still active in established MS. What this experiment is not telling us is which population of T-cells is the culprit as CD4+, CD8+ and T-regulatory cells express CTLA-4 and are hence affected by Ipilimumab. Nor is it telling us about the APC side, which APC is stimulating the T-cells. Is it the B-cell, the macrophage/microglia or another APC?

The moral of this story is that it takes two to tango; the T-cell and its APC. The question is which APC is the preferred partner for the T-cell in MS. Based on the evidence the B-cell seems to be the dominant partner, but who knows in the presence of peripheral B-cell depletion other less dominant partners may take to the floor.

Gettings et al. Severe relapse in a multiple sclerosis patient associated with ipilimumab treatment of melanoma. Mult Scler. 2015 Apr;21(5):670.

56-year-old male, diagnosed in December 1997 with RRMS. Treated with glatiramer acetate in February 1998. Relatively good response to GA with only sensory relapses. In 2005 methotrexate was added. His MS stabilized and he was free of relapses from 2005 to 2013 with a slight increase in disability from an Expanded Disability Status Scale (EDSS) score of 1 to 1.5. In September 2009 diagnosed with melanoma. He had a recurrence in November 2012 with metastases to soft tissue and lymph nodes. He was started on ipilimumab. Methotrexate and glatiramer acetate were stopped prior to initiating ipilimumab. Within one month, he presented with subacute onset of left lower extremity hemiparesis, gait dysfunction and ataxia. An MRI revealed a new left centrum semiovale enhancing lesion consistent with active demyelination. His symptoms improved with high dose methylprednisolone. Ipilimumab was continued. In May 2013 he was readmitted for transient left-sided weakness and ataxia. MRI revealed an enhancing lesion in the right corona radiata. Follow-up imaging revealed a second enhancing lesion in the right frontal lobe and he was restarted on glatiramer acetate and steroids.

To T or not to T

I have always wondered why the genomic experts in the field of MS haven’t been able to sort out why specific human leukocyte antigen (HLA) subtypes increase your risk of getting MS and others don’t.



HLA or human leukocyte antigens are the so-called signposting proteins that antigen presenting cells (APCs) use to communicate with T-cells. The APCs continuously sample the environment and present small peptides in their HLA molecules to T-cells. The HLA molecules interact with the so-called T-cell receptor (TCR) and if the peptide (message) that has been loaded in the HLA groove (signpost) and TCR, which acts as a molecular reader, fit perfectly it tells the T-cell that it should go on the attack. In the context of MS, this attack is considered to autoimmune or dysfunctional and against a self-peptide. However, the attack could be entirely appropriate and targeted against a foreign protein or a self-protein that has been altered by a process called post-translational modification. Interestingly, smoking and solvents, exposure to which are both risk factors for developing MS, are two environmental exposures that are known to cause post-translational modifications of proteins.

The following YouTube animation shows you an example of how a TCR (reader) interacts with a specific HLA molecule (signpost) and the peptide (message) in the groove of a specific HLA molecule. By watching this video you may appreciate how specific this interaction really is.

The most important genetic risk factor for deevloping MS is the so-called HLA-DRB1*15:01 molecules. If you have one copy of this gene your risk of getting MS is ~3X greater than someone without this gene. If you have two copies your risk of getting MS is about ~6X greater. In other words from a genetic perspective, you don’t want to have the HLA-DRB1*15:01 signposts.

It turns out that there, not all HLA-DRB1*15:01 molecules are made equal and that if you have the African variety, compared to the European variety, your risk of getting MS is 3x lower. Interestingly, the African and European varieties of the HLA-DRB1*15:01 genes differ in their sequence in a way that would affect the so-called peptide binding groove of the HLA molecule. This would mean that they would bind peptides differently and hence affect the way that T-cells may or may not be activated. How interesting?

The African variety of HLA-DRB1*15:01 is presumably older and the genetic change in HLA-DRB1*15:01 that is now known as the European variant must have been selected for after man left Africa and migrated into Europe. The most likely evolutionary selection pressure for this selection was repeated exposure to an infection, which selected for this variant, with the later consequence of being an increased risk of getting MS.

What is the significance of these findings? It is telling us that MS risk is related to a very specific HLA-DRB1*15:01 variant and this variant, by definition, must be interacting with a specific family of peptides or possibly a single peptide in our environment or body. Wouldn’t it be great if we could find this peptide or family of peptides? It could potentially lead us to the cause of MS.

It is important to realise that the HLA-DRB1*15:01 association with MS, and these new findings in relation to the African and European variants, is telling us that the T-cell must be the central player, or conductor, in the pathogenesis of MS and must be upstream of the B-cell. I have mulled over this for many years and I can’t think of another way of interpreting these results. Do you agree?

Chic et al. Admixture mapping reveals evidence of differential multiple sclerosis risk by genetic ancestry. PLoS Genet. 2019 Jan 17;15(1):e1007808. doi: 10.1371/journal.pgen.1007808.

Multiple sclerosis (MS) is an autoimmune disease with high prevalence among populations of northern European ancestry. Past studies have shown that exposure to ultraviolet radiation could explain the difference in MS prevalence across the globe. In this study, we investigate whether the difference in MS prevalence could be explained by European genetic risk factors. We characterized the ancestry of MS-associated alleles using RFMix, a conditional random field parameterized by random forests, to estimate their local ancestry in the largest assembled admixed population to date, with 3,692 African Americans, 4,915 Asian Americans, and 3,777 Hispanics. The majority of MS-associated human leukocyte antigen (HLA) alleles, including the prominent HLA-DRB1*15:01 risk allele, exhibited cosmopolitan ancestry. Ancestry-specific MS-associated HLA alleles were also identified. Analysis of the HLA-DRB1*15:01 risk allele in African Americans revealed that alleles on the European haplotype conferred three times the disease risk compared to those on the African haplotype. Furthermore, we found evidence that the European and African HLA-DRB1*15:01 alleles exhibit single nucleotide polymorphism (SNP) differences in regions encoding the HLA-DRB1 antigen-binding heterodimer. Additional evidence for increased risk of MS conferred by the European haplotype were found for HLA-B*07:02 and HLA-A*03:01 in African Americans. Most of the 200 non-HLA MS SNPs previously established in European populations were not significantly associated with MS in admixed populations, nor were they ancestrally more European in cases compared to controls. Lastly, a genome-wide search of association between European ancestry and MS revealed a region of interest close to the ZNF596 gene on chromosome 8 in Hispanics; cases had a significantly higher proportion of European ancestry compared to controls. In conclusion, our study established that the genetic ancestry of MS-associated alleles is complex and implicated that difference in MS prevalence could be explained by the ancestry of MS-associated alleles.

A new old technology

There is nothing more exciting than a new, but old, technology!
 

A problem we face when making the case for a list of essential medications to treat MS in resource-poor settings is the issue of MS misdiagnosis and the inability to monitor MS disease activity using MRI in these settings. MRI is an expensive innovation and a large number of countries simply don’t have enough MR scanners to go around. How can the small number of pwMS in these countries hijack the scanners for monitoring, when they are needed for diagnostic imaging? In addition, MRI is expensive and often has to be paid for privately. I remember in the early days of MRI this being the case in South Africa; i.e. all the scanners were in the private sector and we had to make a request on a case-by-case basis to get state-funded patients scanned. 
 
With this backdrop, I find the study below very illuminating. They simply analysed CT scans using histogram analysis, which was able to identify pwMS from appropriate controls. Why is this important? CT scanning is widely available, even in resource-poor settings, so being able to use CT to aid in the diagnosis of MS would address at least one of the concerns of our MS Essential Medicines List critics. The question would be logistics, i.e. how easy would it be to implement this sort of analysis in these environments? Maybe it could be done in the cloud using AI tools? Most medical centres, even in resource-poor countries, are now web-enabled. They could simply upload the data and get back a report on the likelihood of the patient having MS. 
 
Please note the reason for doing neuroimaging in the work-up for someone with possible MS is to exclude possible MS mimics. A CT scan goes a long way in doing just this. If you then get back a histogram analysis that makes MS likely, combining this with CSF analysis and other tests you may be able to get the necessary sensitivity and specificity for the diagnosis of MS in these settings. In fact, the ROC (receiver operating curve) analysis in this paper suggests the sensitivity and specificity of the histogram analysis technique are high enough to make this a viable option. 
 
All we need now is an MSologist or neurologist working in a resource-poor setting to take-up the challenge and to test whether or not CT-scanning can be used instead of MRI to make the diagnose of MS. This could transform the diagnostic work-up of people with possible MS in these environments.
 
There is nothing more exciting than a new, but old, technology; i.e. adapting an old technology to address an unmet need in the now. 
 
From: Cauley and Fielden. Tomography 2018 Dec;4(4):194-203.
Cauley and Fielden. A Radiodensity Histogram Study of the Brain in Multiple Sclerosis. Tomography 2018 Dec;4(4):194-203.

Multiple sclerosis (MS) is a progressive neurodegenerative disease, affecting 1 million Americans and 2.5 million people globally. Although the diagnosis is made clinically, imaging plays a major role in diagnosing and monitoring disease progression and treatment response. Magnetic resonance imaging (MRI) has proven sensitive in imaging MS lesions, but the characterization offered by routine clinical MRI remains qualitative and with discrepancies between imaging and clinical findings. We investigated the ability of digital analysis of non-contrast head computed tomography (CT) images to detect global brain changes of MS. All routine diagnostic head CTs obtained on patients with known MS obtained from 1 of 2 scan platforms from 6/1/2011 to 6/1/2015 were reviewed. Head CT images from 54 patients with MS met inclusion criteria. Head CT images were processed and histogram metrics were compared to age- and gender-matchedcontrol subjects from the same CT scanners during the same time interval. Histogram metrics were correlated with plaque burden as seen on MRI studies. Compared with control subjects, patients had increased total brain radiodensity (P < .0001), further characterized as an increased histogram modal radiodensity (P < .0001) with decrease in histogram skewness (P < .0001). Radiodensity decreased with increasing plaque burden. Similar findings were seen in the patients with only mild plaque burden subgroup. Radiodensity is a unique tissue metric that is not measured by other imaging techniques. Our study finds that brain radiodensity histogram metrics highly correlate with MS, even in cases with minimal plaque burden.

 
CoI: none
Exit mobile version
%%footer%%