Tuesday, 17 January 2017

Is there chronic blood loss in progressive MS?

Wellcome Open Res. 2016 Nov 15;1:10.

Free serum haemoglobin is associated with brain atrophy in secondary progressive multiple sclerosis.

Lewin A, Hamilton S, Witkover A, Langford P, Nicholas R, Chataway J, Bangham CR.



Abstract


Background A major cause of disability in secondary progressive multiple sclerosis (SPMS) is progressive brain atrophy, whose pathogenesis is not fully understood. The objective of this study was to identify protein biomarkers of brain atrophy in SPMS. Methods We used surface-enhanced laser desorption-ionization time-of-flight mass spectrometry to carry out an unbiased search for serum proteins whose concentration correlated with the rate of brain atrophy, measured by serial MRI scans over a 2-year period in a well-characterized cohort of 140 patients with SPMS. Protein species were identified by liquid chromatography-electrospray ionization tandem mass spectrometry. Results There was a significant (p<0.004) correlation between the rate of brain atrophy and a rise in the concentration of proteins at 15.1 kDa and 15.9 kDa in the serum. Tandem mass spectrometry identified these proteins as alpha-haemoglobin and beta-haemoglobin, respectively. The abnormal concentration of free serum haemoglobin was confirmed by ELISA (p<0.001). The serum lactate dehydrogenase activity was also highly significantly raised (p<10-12) in patients with secondary progressive multiple sclerosis. Conclusions An underlying low-grade chronic intravascular haemolysis is a potential source of the iron whose deposition along blood vessels in multiple sclerosis plaques contributes to the neurodegeneration and consequent brain atrophy seen in progressive disease. Chelators of free serum iron will be ineffective in preventing this neurodegeneration, because the iron (Fe2+) is chelated by haemoglobin.


This work is performed using the serum samples from the MS-STAT study which showed a small yet significant reduction in the rate of brain volume with high-dose (80mg) simvastatin. The aim of this study was to find potential biomarkers of brain atrophy.

Here, Lewin et al. report a new potential candidate; free serum haemoglobin. It does not come as news to me that this wasn't picked up by other seasoned proteomics researchers before, as it's easy to overlook proteins where there is lack of substantiating evidence in the disease under question. That is, this may be present in previous screens but not flagged as significant by the researchers reporting it! In the same way I'm surprised that neurofilament proteins were not flagged in Lewin's work as I know them to be a consistent finding in sample screens for progressive MS and increased with brain volume loss...

Proteomics also suffers from pre-analytical variations i.e. sample processing, storage etc., which may lead to differential findings from group to group. This is why, a confirmatory check is needed (i.e. the same change is demonstrated by another methodology, for example ELISA), which is what is performed here. They demonstrate that there is a similar rise in serum haemoglobin using commercial test (provided by Abcam). But they do not provide any validation data on this, which is a paramount requirement in this field of research. The European Biomarker Consortium provided a guidance document with regard to reporting on new biomarkers (Guidelines for uniform reporting of body fluid biomarker studies in neurologic disorders. Gnanapavan S, Hegen H, Khalil M, Hemmer B, Franciotta D, Hughes S, Hintzen R, Jeromin A, Havrdova E, Tumani H, Bertolotto A, Comabella M, Frederiksen J, Álvarez-Cermeño JC, Villar L, Galimberti D, Myhr KM, Dujmovic I, Fazekas F, Ionete C, Menge T, Kuhle J, Keir G, Deisenhammer F, Teunissen C, Giovannoni G), to avoid scientists spending time on researching random findings! I suppose it's fine because the authors state that "these results do not suggest that free serum haemoglobin concentration is useful in the differential diagnosis of neurological disease", which is smart!

Let's look at the hypothesis, this is an interesting one and well worth taking a second look. We know that in all neurodegenerative disorders, including MS, there is an increase in the iron deposition in the brain. Normally, there is iron bound to haemoglobin in red blood cells. When you spin blood to obtain the serum the red blood cells (which are heavier) separate out at the bottom of the tube. Therefore, any free blood in the sample, outside of rubbish venepuncture technique (I'm assuming that haemolysed samples were excluded prior to analysis, as this is a requirement for proteomic studies), is indicative of blood break down (or haemolysis). There is then a possibility, that this may cause problems (see above figure for a potential mechanism); although I don't think this is a direct causal evidence for brain atrophy (i.e. may be epiphenomena), as autoimmune haemolytic anaemia (blood disorder which is both genetic and caused by other illnesses) has no reported mention of brain volume loss. Clearly, more work is needed in this area. Moreover, other groups looking at this also need to examine haptoglobin levels, as haptoglobin binds free serum haemoglobin and genetic variations in haptoglobin between individuals has been reported to affect free serum haemoglobin levels.

Finally, there is no observed treatment effect on free serum haemoglobin of high-dose simvastatin. Lewin et al. state "This effect was independent of the beneficial treatment effect of simvastatin, because there was no association between free haemoglobin concentration and simvastatin treatment", they also state "The results presented here show that a rise in the concentration of free haemoglobin in the serum was associated with the rate of brain atrophy in this cohort of patients with SPMS". Are they, therefore, implying that high-dose simvastatin does not in fact lower the likelihood of brain atrophy! Maybe, I'm putting words in their mouth!! Please place me on a direct line to a good statistician!

Monday, 16 January 2017

#ClinicSpeak: have you been taken for a ride by a prostitute called Turmeric?

We need an evidence base to support the use of Turmeric in MS. #ClinicSpeak #MSBlog

So many of my patients have asked what I  think of Turmeric as a treatment for MS and my stock answer has been that there is no class 1 or 2 evidence (randomised controlled trials) to support the claims that it helps people with MS. Nothing has changed except I can now say that there is now no biological evidence that Turmeric has any medicinal effects

The editorial from last week's Nature on a meta-analysis suggests we have all been duped by the chemical properties of the curcumin, the proposed active ingredient in Turmeric. They show that curcumin is a promiscuous compound and interferes with most drug-screening assays, which have led to false claims about its biological effects. It is a molecular prostitute, i.e. binding promiscuously to many proteins and membranes, and giving false signals or faking it.


I would be interested to know how many of you have tried Turmeric for your MS.



Monya Baker. Deceptive curcumin offers cautionary tale for chemists. Nature 541, 144–145 (09 January 2017) doi:10.1038/541144a

Spice extract dupes assays and leads some drug hunters astray.

Excerpts:

..... Inside the golden-yellow spice turmeric lurks a chemical deceiver: curcumin, a molecule that is widely touted as having medicinal activity, but which also gives false signals in drug screening tests. For years, chemists have urged caution about curcumin and other compounds that can mislead naive drug hunters.

......  the most comprehensive critical review yet of curcumin — concluding that there’s no evidence it has any specific therapeutic benefits, despite thousands of research papers and more than 120 clinical trials. The scientists hope that their report will prevent further wasted research and alert the unwary to the possibility that chemicals may often show up as ‘hits’ in drug screens, but be unlikely to yield a drug......

...... “Curcumin is a cautionary tale,” says Michael Walters, a medicinal chemist at the University of Minnesota in Minneapolis, and lead author of the review (K. M. Nelson et al. J. Med. Chem. http://dx.doi.org/10.1021/acs.jmedchem.6b00975; 2017), published on 11 January......

......  Commonly used drug screens detect whether a chemical latches on to a binding site of a protein implicated in disease — a hint that it may be the starting point for a drug. But some molecules, such as curcumin, seem to show such specific activity when there is none. The molecules may fluoresce naturally, foiling attempts to use fluorescence as a signal of protein binding. They may disrupt cell membranes, duping assays that try to spot drugs targeting specific cell-membrane proteins. And they may surreptitiously degrade into other compounds that have different properties, or contain impurities that have their own biological activity......

...... Chemists call these irritants PAINS (pan-assay interference compounds) — and curcumin is one of the worst.....

...... Misinterpretations feed on themselves, Walters says. Curcumin gets reported as having an effect even if the assay was flawed. “People accept what is in the literature as being correct and then build a hypothesis, even though it doesn’t hold up.” And scientists don’t seem to check the literature to see whether compounds have been flagged as problematic. At least 15 articles on curcumin have been retracted since 2009 and dozens more corrected......

....... But the review shows that getting real answers will be tough, says Bill Zuercher, a chemical biologist at the University of North Carolina at Chapel Hill. “It may very well be the case that curcumin or turmeric extracts do have beneficial effects, but getting to the bottom of that is complex and might be impossible,” he says. Walters isn’t confident that his report will stop poorly conducted research. “The people who should be reading this probably won’t,” he says ......

Nelson et al. The Essential Medicinal Chemistry of Curcumin. J Med Chem. 2017 Jan 11. doi: 10.1021/acs.jmedchem.6b00975.

Curcumin is a constituent (up to ∼5%) of the traditional medicine known as turmeric. Interest in the therapeutic use of turmeric and the relative ease of isolation of curcuminoids has led to their extensive investigation. Curcumin has recently been classified as both a PAINS (pan-assay interference compounds) and an IMPS (invalid metabolic panaceas) candidate. The likely false activity of curcumin in vitro and in vivo has resulted in >120 clinical trials of curcuminoids against several diseases. No double-blinded, placebo controlled clinical trial of curcumin has been successful. This manuscript reviews the essential medicinal chemistry of curcumin and provides evidence that curcumin is an unstable, reactive, nonbioavailable compound and, therefore, a highly improbable lead. On the basis of this in-depth evaluation, potential new directions for research on curcuminoids are discussed.

Sunday, 15 January 2017

#ClinicSpeak & #ResearchSpeak: obesity comes up trumps

How do we stop the adolescent obesity crisis? It is important for MS. #ClinicSpeak #ResearchSpeak 

Adolescent obesity is a risk factor for developing MS. Is it Chicken or Egg? Is obesity simply associated with MS due to another factor or does obesity act in the MS causal pathway. An example of an association would be that its actually low vD levels, or lack of outdoor activity and less sun exposure, that is the causal factor. People who have less outdoor activity tend to be more sedentary and hence more likely to be obese. The risk factor here is less outdoor activity and not the associated obesity. Obesity could be causal if some part of adipose tissue biology interacts with the MS causal pathway. An example of this is could be one of pro-inflammatory mediators that adipose tissue produces, and there are many such mediators, may prime the immune system to develop autoimmunity. In other words if there was less adipose  tissue, and as a result less adipose tissue induced systemic inflammation, then the risk of autoimmunity will drop. 

Another way adipose tissue may interfere with the causal pathway is actually via vD metabolism. Adipose tissue may lower systemic vD levels by consuming vD as part of its metabolism. The low vitamin D level, and not the obesity, that is the risk factor here.

One way to answer the association vs. causation question is to do a randomised controlled trial of a dietary, or pharmacological intervention, which reverses or prevents adolescent obesity, and to see if the intervention reduces the risk of developing MS. This type of trial would be very difficult to do and may actually not be feasible. 

Is there a cheaper, cleverer, way to do randomised-controlled trial to prove causation? Yes, there is a clever way using Mendelian randomization and seeing if the genetic variants that are linked to obesity are risk factors for developing MS. The study below done using people from California registered with the Kaiser Permanente HMO and a replication sample from Sweden showed just that. The investigators constructed a weighted genetic risk score using genetic variants previously established to predict obesity. Subjects with higher genetically-induced obesity scores had a higher risk of developing MS. Although the investigators controlled for birth year, sex, education, smoking status, ancestry, and genetic predictors of MS they clearly couldn't control for other important con-founders that are very relevant to this analysis, for example dietary factors, exercise - in particular out-door activity - and vD levels. Despite this this study does suggest that obesity is probably part of the MS causal pathway and that if we want to reduce the incidence of MS in the population we need to tackle the problem of adolescent obesity. Now that is much easier said than done!


Gianfrancesco et al. Causal Effect of Genetic Variants Associated With Body Mass Index on Multiple Sclerosis Susceptibility. Am J Epidemiol. 2017 Jan 9. doi: 10.1093/aje/kww120.

Background: Multiple sclerosis (MS) is an autoimmune disease with both genetic and environmental risk factors. Recent studies indicate that childhood and adolescent obesity double the risk of MS, but this association may reflect unmeasured confounders rather than causal effects of obesity. 

Methods: We used separate-sample Mendelian randomization to estimate the causal effect of body mass index (BMI) on susceptibility to MS. Using data from non-Hispanic white members of the Kaiser Permanente Medical Care Plan of Northern California (KPNC) (2006-2014; 1,104 cases of MS and 10,536 controls) and a replication data set from Sweden (the Epidemiological Investigation of MS (EIMS) and the Genes and Environment in MS (GEMS) studies, 2005-2013; 5,133 MS cases and 4,718 controls), we constructed a weighted genetic risk score using 97 variants previously established to predict BMI. 

Results: Results were adjusted for birth year, sex, education, smoking status, ancestry, and genetic predictors of MS. Estimates in KPNC and Swedish data sets suggested that higher genetically induced BMI predicted greater susceptibility to MS (odds ratio = 1.13, 95% confidence interval: 1.04, 1.22 for the KPNC sample; odds ratio = 1.09, 95% confidence interval: 1.03, 1.15 for the Swedish sample). 

Conclusions: Although the mechanism remains unclear, to our knowledge, these findings support a causal effect of increased BMI on susceptibility to MS for the first time, and they suggest a role for inflammatory pathways that characterize both obesity and the MS disease process.

No Evidence of Disease activity with daclizumab

#Clinical Speak. Where to position daclizumab

#AchillesHealSpeak.Is MS a Tcell issue

Kappos L, Havrdova E, Giovannoni G, Khatri BO, Gauthier SA, Greenberg SJ, You X, Wang P, Giannattasio G. No evidence of disease activity in patients receiving daclizumab versus intramuscular interferon beta-1a for relapsing-remitting multiple sclerosis in the DECIDE study. Mult Scler. 2016 Dec 1:1352458516683266.


BACKGROUND:

No evidence of disease activity (NEDA) is a composite endpoint being increasingly applied as an outcome measure in clinical trials as well as proposed for individual therapeutic decisions in multiple sclerosis (MS).

OBJECTIVE:

Assess the proportion of patients with relapsing-remitting MS achieving NEDA in the DECIDE study of daclizumab 150 mg subcutaneous versus intramuscular interferon beta-1a 30 µg for 96-144 weeks.

METHODS:

NEDA was defined as no relapses, no onset of 12-week confirmed disability progression (CDP), no new/newly enlarging T2 hyperintense lesions (NET2), and no gadolinium-enhancing (Gd+) lesions. Logistic regression models adjusted for baseline covariates compared treatment groups for baseline to week 96, weeks 0-24, and weeks 24-96.

RESULTS:

From baseline to week 96, more daclizumab versus intramuscular interferon beta-1a patients achieved NEDA (24.6% vs 14.2%; odds ratio (OR; 95% confidence interval): 2.059 (1.592-2.661); p < 0.0001). ORs for clinical NEDA (no relapses, no CDP) and magnetic resonance imaging (MRI) NEDA (no NET2, no Gd+ lesions) were 1.651 (1.357-2.007; p < 0.0001) and 2.051 (1.628-2.582; p < 0.0001), respectively. ORs in favor of daclizumab for weeks 24-96 were consistently higher than for weeks 0-24.

CONCLUSION:

More daclizumab versus intramuscular interferon beta-1a patients achieved NEDA early in DECIDE, with effects increasing over time.

Here is one for ProfG to do as he is a coauthor of the paper, he may have an answer and maybe this is going to be something that he will have to wrestle with, that is if NICE approve the treatment. I suspect they will after abit of haggling over price.  

But the big question is going to be where is this drug going to be positioned?

Based on its effect on relapses it is in the moderately effective treatments and is injected every month. Looking at the rate of NEDA, it is better than beta interferon but a long way behind the highly effective agents.  

There is a risk of skin reactions with this agents and in a few percent of cases it can be quite severe. Maybe this is because it depletes T reg cells because they express CD25 and daclizumab blocks CD25. 

This is the high affinity interleukin-2 (T cell growth factor). 
Does this work because it blocks activated T cells which express the IL-2 receptor? This was surely the logic for trying it because if they knew about Tregs then surely T cell immunologists would not have attempted to use it.

Block Tregs and MS should get worse if we follow the dogma, because T regs block autoimmunnity. This the dogma and something that must make the T cell brigade wiggle
Surely MrT will agree with this. 

Maybe MrT will give the answer...it doesn't deplete Tregs enough for it to be important. Maybe the job of the Treg is to stop autoimmunity occuring in the first place, but once immunity has been intitiated they don't do much?

However, it doesn,t make MS worse so again what does this say about T cells causing MS? 

However when you block the CD25 the circulating levels of IL-2 increase this binds to the intermediate affintiy interleukin 2 receptor and this is expressed on natural killer cells and so they expand. Natural killer cells are a type of immune cells involved in killing cancers and infections. So is this how daclizumab works, by being more anti-viral?  So is this saying that there is a virus linked to MS?

Is it working some other way than T cells, this agent has to tell us something about MS because after all it is doing something.

The big dilema is how to position this drug? 
It has efficacy of some first line drugs, but side effect that may lead to second line (being too expensive normally guarentees this with NICE). 
How do the companies marketing the drug, position the drug? As they have 
loads in their stable.

Not being a clinician I don't have to conudrm

CoI Prof G is author

Saturday, 14 January 2017

#BrainHealth & #ClinicSpeak: is the couch potato effect the chicken or the egg?

How good are you at sticking to your New Year's resolutions? #BrainHealth #ClinicSpeak




“There is a fatality about good resolutions – that they are always made too late”


How are you feeling this morning? Tired, lethargic, hungover, depressed? To much red wine last night? Full of self-loathing for having eaten too much and for missing your exercise routine this week? Lifestyle optimisation is one of the hardest things to achieve in life. How do we, HCPs, prescribe a healthy lifestyle and get people to adhere to it? 

The study below, although small, links sedentary behaviour to brain volume loss in pwMS. The less active you are the smaller your brain. This is an important observation and needs to be confirmed. It is important because brain size, or neuronal reserve, and cognitive reserve (education) protects you against age-related and MS-related cognitive impairment. The issue that needs to be established is this observation simply an association or is it causal. 

It would be associative if MS caused people to exercise less; in other words the more severe your MS, the more brain volume you lose. It is easy to understand that the more severe your MS, the more neurological impairments you will have, the less likely you are to exercise. Please note these neurological impairments could be physical, for example leg weakness that may make it harder to exercise, or hidden, for example MS-related anxiety and depression may reduce your motivation to exercise. 

The observation would be causal if we could show that exercise could maintain brain volume independent of other factors associated with preservation of brain reserve in MS, e.g. DMTs, diet, lack of or treatment of comorbidities, not smoking, low alcohol intake, etc. 

Finding out whether this observation is causal is very difficult and it will require a large randomised-controlled trial, which for an exercise intervention is very difficult and some would say impossible to achieve. The other approach is simple, there is enough evidence that exercise is good for you regardless of whether, or not, it is maintaining your brain volume. Exercise improves sleep, fatigue, mood and anxiety. Exercise helps maintain you metabolically, i.e. your weight, glucose levels, blood pressure, etc. Exercise outside of the MS space protects, or delays, you from developing age-related cognitive impairment. So why wouldn't you want to exercise? The problem is that if you have disabilities exercising may be difficult. This is why you may need to see a physio, or physical, therapist to help. Our physiotherapists tell us that regardless of disability there are exercise programmes that can be designed specifically for you. I know that the above is easier said than done, but unless you try you won't know. 

If you are a healthcare professional you need to practice what you preach. You can't be recommending healthy lifestyle interventions to your patients unless you are trying to adopt them yourself. You have to walk the talk. This is why we launched the Barts-MS Brain Health Challenge last year; to motivate you to improve your health and wellness so that when you advise your patients you sound more credible and you have the moral high ground. To quote one of my favourite clichés 'Just Do It'


Klaren et al. Objectively measured sedentary behavior and brain volumetric measurements in multiple sclerosis. Neurodegener Dis Manag. 2017 Jan 11. doi: 10.2217/nmt-2016-0036.

AIM: This study examined the association between sedentary behavior patterns and whole brain gray matter (GM), white matter (WM) and subcortical GM structures in persons with multiple sclerosis (MS).

METHODS: 36 persons with MS wore an accelerometer and underwent a brain MRI. Whole brain GM and WM and deep GM structures were calculated from 3D T1-weighted structural brain images.

RESULTS: There were statistically significant (p < 0.01) and moderate or large associations between number of sedentary bouts/day and brain volume measures. The primary result was a consistent negative association between number of sedentary bouts/day and whole brain GM and WM, and deep GM structures.

CONCLUSION: We provide novel evidence for decreased brain volume as a correlate of a sedentary behavior pattern in persons with MS.