Thursday, 30 March 2017

What Does B cell depletion do in Animules

#MSresearch B cells role in EAE more wishful thinking

Eseberuo Sefia, Gareth Pryce, Ute-Christiane Meier, Gavin Giovannoni, David Baker Depletion of CD20 B cells fails to inhibit relapsing mouse experimental autoimmune encephalomyelitis. Mult scleros is and related disorders DOI: http://dx.doi.org/10.1016/j.msard.2017.03.013

Background. Multiple sclerosis (MS) is often considered to be a CD4, T cell-mediated disease. This is largely based on the capacity of CD4 T cells to induce relapsing experimental autoimmune encephalomyelitis (EAE) in rodents. However, CD4-depletion using a monoclonal antibody was considered unsuccessful and relapsing MS responds well to B cell depletion via CD20 B cell depleting antibodies. The influence of CD20 B cell depletion in relapsing EAE was assessed.
Methods. Relapsing EAE was induced in Biozzi ABH mice. These were treated with CD20-specific (18B12) antibody and the influence on CD45RA-B220 B cell depletion and clinical course was analysed.
Results. Relapsing EAE in Biozzi ABH failed to respond to the marked B cell depletion induced with a CD20-specific antibody. In contrast to CD20 and CD8-specific antibodies, CD4 T cell depletion inhibited EAE.
Conclusion. Spinal cord antigen-induced disease in ABH mice is CD4 T cell-dependent. The lack of influence of CD20 B cell depletion in relapsing EAE, coupled with the relatively marginal and inconsistent results obtained in other mouse studies, suggests that rodents may have limited value in understanding the mechanism occurring following CD20 B cell depletion in humans


If is perhaps apt that this paper has surfaced this week, just as Ocrelizumab gets a licence in the USA. 

This will mean a flurry of activity to do more work to sort out disease mechanisms targeted, so a load more transgenic mice will be made and used.

Should we say Schtop!

We recently reported on a review on B cells in MS.
https://multiple-sclerosis-research.blogspot.com/2017/03/more-on-b-cellswe-dont-all-have-same.html

They went through the mechanisms of how CD20 depleting antibodies work.

1. They dismissed a roll for antibodies as CD20 does not quickly deplete antibodies, because it does not deplete plasma cells

2. They didn't even think of the viral reservoir idea.

3. They said that they worked on antigen presentation, 
    because that is what the animals studied showed.

I said "If the animal results are based on dogey-ground, 
Where does it leave the hypothesis?" 

So hot of the press...Here we go.

What did anti-CD20 do in the beasties?

Major depletion of B cells, but that is where the good data ends.

What does it do Relapsing EAE? 
In our hands........Nada...Nyet...Nothing!

However, deplete CD4 T cells and disease is gone!

So how do you report this?

I thought we could put it in the context of other studies

So what have other people found? 

It made us look at the data 

So rather than write about it, where it would go in one ear and out the next.

I thought it was easier to pay for the copyright fees to get permission to reproduce the figures in the paper, so you can all see for yourself.

I showed DrK the figure below, before he knew what the content was and he said "What ever it is, it doesn't look very good"

What's your take?



(A) Shows depending on when start treatment to induce CD20 B cell depletion it can either: 
  • Augment
  • Do Nothing
  • Inhibit Disease

But let’s face it. It’s only a partial inhibit, not a wipe out like fingolimod or CD52 antibody could do.

(C) Shows so called B cell-dependent EAE where anti-CD20 works, there is a non-B dependent EAE induced with peptide that doesn't work. 

However, I thought “Hang on. That's the same EAE used in A & C were the antibody is working, so is it B cell independent?

In addition if you treat before disease induction it's worse in (A), but better in (B) and (C). So not consistent.

But really as DrK says. The effect in (A) & (C) are rather rubbish.

So the effect in (B) saves the day...yeah it flat lines disease.

But look at the graph at the bottom of (B) on the left. It says B cells were depleted out or sight. But in (B) on right CD4 T cells were also depleted out of sight, so if you deplete T cells with anti-CD20.....it works in animals. So the answer is that the results says that rodent EAE is a T cell mediated disease.

I have no issues with that, but as we have been saying it looks like T cell depletion isn’t that effective in MS.

So no major T cell Depletion with the anti-CD20 antibody we used and there was no effect on EAE.

So if it is antigen-presentation?
Shouldn't the B cell depletion do better if it was?

Are you still an antigen-presenting B cell fan?

Yes it happens.
But, is this how anti-CD20 works in MS?

Maybe Mice can't give us the answer. 
Maybe we should also say marmoset EAE failed to predict the effect of BAFF/APRIL 
Maybe the answer can only be found by studying humans

CoI: This is work from TeamG

Wednesday, 29 March 2017

#NewsSpeak: an eagle called ocrelizumab has landed

FDA licenses ocrelizumab for both relapsing and primary progressive forms of MS. #MSBlog #NewsSpeak #Ocrelizumab

Yesterday was a pretty momentous day for people with MS (pwMS). The FDA licensed ocrelizumab for people with PPMS. The killjoys amongst you will say 'What? The efficacy of ocrelizumab is so small in PPMS that it won't make a difference'. My response to them would be 'Bullshit!' If you have PPMS you would no doubt be celebrating. When innovation happens it is often small and in incremental steps. The ocrelizumab in PPMS trial shows that we can modify the more advanced stages of MS. What you have to realise that the small differences over 2-3 years would become much larger over 5-10, and possibly 20, years. In addition, ocrelizumab was almost twice as effective in preserving arm and hand function (9HPT) when compared to lower limb function (EDSS and T25FW) in the PPMS trial. The latter is explained by our length-dependent axonopathy, therapeutic lag and asynchronous progressive MS hypotheses

This should be a time for quite reflection, deep thought and then asking the question where next? I think most of us at Barts-MS would say we should be taking ocrelizumab into more advanced MS, including wheelchair users (#ThinkHand), and as a combination therapy with add-on neuroprotectants and drugs to target the intrathecal plasma cell. 




CoI: multiple, I am a member of the phase 3 ocrelizumab steering committee

A BAT associated with MS suceptibility

Our number one viewed post is how cats are associated with MS susceptibility, this new study links a BAT to MS susceptibility


Galarza-Muñoz G, Briggs FB, Evsyukova I, Schott-Lerner G, Kennedy EM, Nyanhete T, Wang L, Bergamaschi L, Widen SG, Tomaras GD, Ko DC, Bradrick SS, Barcellos LF, Gregory SG, Garcia-Blanco MA. Human Epistatic Interaction Controls IL7R Splicing and Increases Multiple Sclerosis Risk. Cell. 2017 Mar 23;169(1):72-84.e13.

Multiple sclerosis (MS) is an autoimmune disorder where T cells attack neurons in the central nervous system (CNS) leading to demyelination and neurological deficits. A driver of increased MS risk is the soluble form of the interleukin-7 receptor alpha chain gene (sIL7R) produced by alternative splicing of IL7R exon 6. Here, we identified the RNA helicase DDX39B as a potent activator of this exon and consequently a repressor of sIL7R, and we found strong genetic association of DDX39B with MS risk. I
ndeed, we showed that a genetic variant in the 5' UTR of DDX39B reduces translation of DDX39B mRNAs and increases MS risk. Importantly, this DDX39B variant showed strong genetic and functional epistasis with allelic variants in IL7R exon 6. This study establishes the occurrence of biological epistasis in humans and provides mechanistic insight into the regulation of IL7R exon 6 splicing and its impact on MS risk.

There are about 150 known genes associated with susceptibility to MS. The major locus is the major histocompatilibility complex which is the one that gives you a DNA fingerprint but controls how your immune response recognises infections. The next set of discoveries found the interleukin 7 receptor.



IL-7 is a haematopoietic growth factor secreted by stromal cells in the bone marrow (Place where T and B cells are formed) and thymus (placed where T cells are educated). IL-7 stimulates the differentiation of multipotent (pluripotent) hematopoietic stem cells into lymphoid progenitor cells (as opposed to myeloid (macrophages) progenitor cells where differentiation is stimulated by IL-3). It is important for proliferation during certain stages of B-cell maturation, T and NK cell survival, development and homeostasis 

The interleukin 7 protein acts because it binds to the interleukin-7 receptor. It is made up of two different smaller protein chains - i.e. it is a heterodimer, and consists of two subunits, interleukin-7 receptor-α (CD127) and common-γ chain receptor (CD132).The common-γ chain receptors is shared with various cytokines, including interleukin-2, -4, -9, and -15.Interleukin-7 receptor is expressed on various cell types, including naive and memory T cells and many others. Interleukin-7 receptor has been shown to play a critical role in the development of immune cells called lymphocytes - specifically in a process known as V(D)J recombination (important in antigen recognition) blocking apoptosis (cell death by cell suicide) is an essential function of this protein during differentiation and activation of T lymphocytes.

What about B cells? 

IL-7R (CD127) is down regulated as B cells mature but it can be involved in immunoglobulin (antibody) VDJ re-arrangement and can promote B cell survival and proliferation.

It has been shown that Interleukin-7 (IL-7) promotes the maintenance and activation of peripheral T cells, whereas it does not act directly on mature B cells due to the lack of IL-7Rα expression on these. However, despite the insensitivity of B cells to IL-7, high concentration of IL-7 can lead to increased B cell survival and antibody production in the presence of T cells, without the use of any further B cell stimulatory signal. IL-7 promoted B cell activation through inducing CD70 expression on resting T cells, particularly on CD4+ memory cells. The interaction of CD70 molecules with the B cell costimulatory receptor CD27 led to B cell proliferation, the accumulation of CD38 + CD20- plasmablasts and antibody production. In addition, IL-7 treatment induced BAFF secretion from resting peripheral T cells thereby promoting B cell survival. IL-7 levels can increase in lymphopenic conditions, in autoimmune diseases or in patients receiving T cell regenerative IL-7 therapy. Based on our findings high IL-7 levels can lead to increased B cell activation by inducing the B cell regulatory proteins CD70 and BAFF in resting T cells. Such activity might be beneficial in short term immune-stimulatory IL-7 therapies; permanently increased IL-7 levels, on the other hand, can contribute to impaired B cell tolerance.

The IL-7R gene has 8 exons (coding bits of DNA), 

Alternative splicing generates a soluble isoform lacking exon 6 and introducing a premature stop codon.

In this study they find that DDX39B also known as BAT-1,
RNA-dependent ATPases that mediate ATP hydrolysis during pre-mRNA splicing. The encoded protein is an essential splicing factor required for association of U2 small nuclear ribonucleoprotein with pre-mRNA, and also plays an important role in mRNA export from the nucleus to the cytoplasm. These genes are all within the human major histocompatibility complex class III region.
which favours the production of the splice variant with the exon 6 so favouring lack of soluble (sIL-7R) which is released from the cell into the solution (blood, fluid between cells=interstitial fluid) .

In this study they found that BAT-1 variants are also risk factors for MS and a vriant that has a different untranslated (DNA part of a gene not made into the protien) region (UTR) associated with risk

The 5′ untranslated region (5′ UTR) (also known as a Leader Sequence or Leader RNA) is the region of an mRNA that is directly upstream from the initiation codon. This region is important for the regulation of translation of a transcript. This region can regulate the translation of the main coding sequence of the mRNA.  The 5′ UTR has been found to interact with proteins relating to metabolism; and proteins translate sequences within the 5′ UTR. 

So the BAT-1 variant associated with MS risk makes less DDX39B meaning that more of the soluble IL7R is made and this is associated with MS risk.

BAT-1 variants show epistasis (The effect of one gene is dependent on the presence of one or more modifier gene) with the variants creating the alternatively spliced variant.

It has to be said although this study exposes how one MS susceptibility gene is acting, MS is polygenic and there are lots of genes and gene combinations leading to MS susceptibility. Each one confers only a minor risk and you can get MS without having the gene(s) and likewise you can have the genes and not get MS.

Tuesday, 28 March 2017

#ClinicSpeak & #ResearchSpeak: community integration

How integrated are you in your community? How has MS affected you socially? #ClinicSpeak #MSBlog #MSResearch

I know I am stuck record, but part of the reason why this blog exists is to tell it how it is. We all know MS is a disabling disease and is associated with loss of quality of life. Social isolation is massive problem in MS; it gets worse with increasing disability and is associated with reduced quality of life. 

The following study shows that the majority of pwMS had 'participation restriction', which not surprisingly increased with higher EDSS scores from 40% (EDSS<4) to 82% (EDSS>5.5). Social participation was more restricted than home integration; for example, fewer than 20% of pwMS were able to shop for groceries alone. Cognitive problems were more closely linked with participation restrictions than motor problems or physical disabilities; i.e. balance, gait and hand dexterity limitations.

The results of this study confirm how disabling MS is socially and supports our campaign to rebrand MS a preventable dementia. Please note an impact on social functioning is one of the core diagnostic features of a dementia. 

Knowing this who wouldn't want their disease treated early and effectively to prevent the downstream social consequences of MS? 



I have uploaded the Community Integration Questionnaire that was used in this study. If you are interested you can complete it yourself. Please note this comes with a warning as it may inform you about the impact MS has had on your social life. 



Cattaneo et al. Participation restriction in people with multiple sclerosis: prevalence and correlations with cognitive, walking, balance and upper limb impairments. Archives of Physical Medicine and Rehabilitation Available http://dx.doi.org/10.1016/j.apmr.2017.02.015

Objective: To calculate percentage of participation restrictions according to disability level in Multiple Sclerosis (MS) and to assess relationship between participation restriction, and cognitive, gait, balance and upper limb deficits.

Design: Cross sectional study

Setting: Rehabilitation unit

Participants: 105 people with MS and 20 healthy subjects (HS) were screened in Belgium and Italy.

Interventions: Not applicable

Main outcome measures: The Community integration questionnaire was used to assess participation in Home, Social and Productive Activities. Percentages of people with MS scores lower than the 10th percentile of those of HS were calculated for each sub scale to categorize the persons with participation restrictions. Cognitive deficits (Symbol Digit Modalities Test), walking disability (25-foot walking test / EDSS), balance disorders (Bohannon Standing Balance Test) and manual dexterity (Nine Hole Peg Test), were recorded.

Results: 77% of participants showed participation restrictions, which increased with higher EDSS scores from 40% (EDSS<4) to 82% (EDSS>5.5). Social participation was more restricted than home integration with less than 20% of participants doing shopping for groceries alone. Cognitive deficits were more highly associated (r=0.60) with participation restrictions than balance (r=0.47), gait (r=-0.45) and hand dexterity (r=0.45) limitations.

Conclusions: Participation restrictions are present in MS and increase with disability level. However, the results also show that multiple sclerosis does not restrict participation in all domains. Participation restriction at home is less restricted compared to social participation. Cognitive disorders are more associated to participation restrictions than physical limitations

End of year round-up may end on a good note for Biogen

Eur J Neurol. 2017 Mar 22. doi: 10.1111/ene.13272. [Epub ahead of print]

Effect of delayed-release dimethyl fumarate on no evidence of disease activity in relapsing-remitting multiple sclerosis: integrated analysis of the phase III DEFINE and CONFIRM studies.

Havrdova E, Giovannoni G, Gold R, Fox RJ, Kappos L, Phillips JT, Okwuokenye M7, Marantz JL.


Abstract
BACKGROUND AND PURPOSE:

Significant effects on clinical/neuroradiological disease activity have been reported in patients with relapsing-remitting multiple sclerosis treated with delayed-release dimethyl fumarate (DMF) in phase III DEFINE/CONFIRM trials. We conducted a post hoc analysis of integrated data from DEFINE/CONFIRM to evaluate the effect of DMF on achieving no evidence of disease activity (NEDA) in patients with relapsing-remitting multiple sclerosis.

METHODS:

The analysis included patients randomized to DMF 240 mg twice daily, placebo or glatiramer acetate (CONFIRM only) for ≤2 years. A time-to-event method was used to estimate the percentage of patients achieving NEDA. Clinical NEDA (no relapses/no 12-week confirmed disability progression) was analysed in the intention-to-treat (ITT) population. Neuroradiological (no new/newly enlarging T2 hyperintense lesions/no gadolinium-enhancing lesions) and overall NEDA (clinical and neuroradiological NEDA) were analysed in the magnetic resonance imaging (MRI) cohort.

RESULTS:

The ITT and MRI populations comprised 1540 and 692 patients, respectively. The percentage of patients with clinical NEDA (ITT population) and neuroradiological NEDA (MRI cohort) was higher with DMF versus placebo over 2 years [clinical NEDA: 38.9% relative reduction; hazard ratio (HR), 0.61; 95% confidence interval (CI), 0.52-0.72; P < 0.0001; neuroradiological NEDA: 40.0% relative reduction; HR, 0.60; 95% CI, 0.49-0.73; P < 0.0001]. The percentage of patients achieving overall NEDA (MRI cohort) was also higher with DMF (26%) versus placebo (12%) over 2 years, with a relative risk reduction of 42.7% (HR, 0.57; 95% CI, 0.48-0.69; P < 0.0001).

CONCLUSIONS:

A significantly higher percentage of patients treated with DMF achieved NEDA status over 2 years compared with placebo.


The year 2016 was a colossal mistake for most and ditto for many of our large biotechs. Firstly, the increasing momentum on biosimilars in the US, closely followed by the twitterings of Donald Trump on soaring drug prices, which certainly did not do any favors for consumer confidence. So if you were pharma, how would you set about re-couping some modicum of composure that you did not have the day before?...Why, remind everyone of your infallibility, that is!!!

As far as treatment success is concerned in MS therapeutics, it's all about NEDA, or No Evidence of Disease Activity (a composite readout based on clinical and MRI measures of disease activity). Biogen, with natalizumab (in their posthoc analysis of the AFFIRM study) were the first to report on such back in 2009; registering under 40% absence of disease activity with natalizumab vs. under 10% in the placebo/no treatment arm over 2 years. Here, again Havrdova et al. evaluate the achievement of NEDA, but this time with the first line oral drug dimethyl fumerate (DMF or tecfidera) using combined analysis from the DEFINE and CONFIRM studies. The bottom line is that percentage of overall NEDA was 26% in the DMF vs 12% in the placebo arm over 2 years (see figure below).

Figure: Effect of delayed‐release DMF (blue) on NEDA in relapsing–remitting multiple sclerosis vs placebo (red): integrated analysis of the phase III DEFINE and CONFIRM studies

So what does this data add to what we already know about DMF? It tells us that DMF is not only effective at single end-points, such as relapse rate reduction and MRI activity, but can achieve a certain degree of overall NEDA as well. NEDA individuals of course have a better prognosis for the future than those who don't achieve NEDA, and that is the key here. Therefore, even on first-line therapy it is possible to achieve this. Of course, the caveat to this is that the success rate of achieving NEDA is even greater with the most highly-active treatments, such as natalizumab and alemtuzumab, but the trade-off is the risk-benefit profile with the latter.

The key, therefore, it would seem in the current climate of MS therapeutics is to be able to cater for all comers. Have the option of the highly-active treatment, but at the same time offer a less effective one with a better risk profile; and there within comes the power to swap strategies to one's complete inner satisfaction.