The 12th International Association for Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (IACFS/ME) Conference was held in Fort Lauderdale, USA from 27–30 October 2016. The conference had a theme of ‘Emerging science and clinical care’. Here is a summary of the discussion from Dr Rosamund Vallings.
The conference, opened by the president Fred Friedberg (NY, USA), was a day for patients, while the medical and research professionals could attend a series of workshops.
The keynote speaker for the opening address at the patient conference was Vicky Whittemore (USA), who heads the National Institute of Neurological Disorders and Stroke at the National Institutes of Health (NIH). A current study is recruiting 40 ME/CFS patients who are within five years of diagnosis. There will be an extensive analysis with bio-specimen collection (www.mecfs.ctss.nih.gov).
If applying for funding, there is a request for information — short term, intermediate term and long-term (www.nih.gov/mecfs). The top 14% of applicants are accepted, and the next 14–24% are good quality applications, but are usually turned down.
Emerging science and clinical care
This was the theme of the main conference the following day.
The plenary session was given by Øystein Fluge (Bergen, Norway) on B-lymphocyte depletion and disease mechanisms in ME/CFS. He described how the drug rituximab was a safe way to target B-cells, leading to B-cell depletion. Their first study involved 30 patients (15 CFS and 15 controls), and after six to 10 months, a positive response was evident in 67% of those on rituximab. Two out of 15 controls had a positive outcome. No adverse effects were reported. To get a sustained response, ongoing infusions were needed (500mg/m2).
In a further study, 18 out of 29 had a clinical response, while 11 out of 29 had no benefit. Of the 18 positive responders, 11 were in remission at three years and five were in remission at five years. Maintenance gives a prolonged response. Response takes time (8–66 weeks). Two patients had allergic reactions and two had late-onset neutropenia. Eight out of 28 had a temporary worsening of their ME/CFS symptoms. One had a sustained worsening.
They do not support treatment outside clinical trials at this stage, until more evidence is available. They are now doing a multi-centre trial on 152 patients. Two infusions are given two weeks apart, followed by maintenance infusions at three, six, nine, and 12 months. Symptoms are scored every second week. The SF36 is administered three times monthly. ‘Sensewear’ armbands are used for seven-day spells.
He posed the question that an autoimmune basis could be suggested for overlapping syndromes such as POTS, CRPS, etc. He questioned whether ME/CFS symptoms are caused by energetic effects such as endothelial dysfunction, i.e. is there inadequate auto-regulation of blood flow? The anaerobic threshold is reached at low workload in these patients. Cause of fatigue may be depletion of intracellular energy metabolism, increased lactate production, insufficient supply of oxygen.
The team are doing: autoantibody screen, peptide array, immune-phenotyping, cytokine analysis, immune-genetic analyses, exome sequencing and metabolic profiling. There is also a focus on amino-acid metabolism as shown in previous studies, and abnormalities were discussed. They are working with the hypothesis that there is a defect in central energy metabolism leading to changes in the serum amino-acid profile. A particular abnormality found in some women was impairment in the pyruvate dehydrogenase (PDH) complex. This was not seen in men. But there was increased 3-methylhistadine likely due to increased endogenous protein catabolism. They are also looking at gene expression in PBMCs — the hypothesis being that there may be obstruction in the central energetic pathway, at the PDH complex level.
Session 1: The latest research in immunology and the microbiome
Jose Montoya (Stanford, USA) showed that exercise testing highlighted the differences in cytokine profile and network between patients with ME/CFS and healthy sedentary controls. Exercise was shown to highlight abnormal cytokines and growth factor profiles in CFS, compared to resting values. The most discriminatory cytokines at 24 hours post-exercise included interleukin 1β, platelet activator inhibitor, CD40 ligand, MIP1α and INFγ. Twenty-four hours post-exercise was found to be the best discrimination between ME/CFS and controls.
Kenny de Meirlier (Brussels, Belgium) found a panel of biomarkers which accurately identifies CFS/ME patients, contributing to the understanding of this disease. High sensitivity and specificity was noted. A panel of four parameters were measured: Il-8, CD14, prostaglandin E2 and absolute CD3/CD57+lymphocytes. Each of these markers relates to the disorder. It is probable that lipopolysaccharide, likely from gut bacteria, plays an important role in pathophysiology of ME/CFS. This all represents a step towards identifying biomarkers.
Jose Montoya (Stanford, USA) gave a further presentation profiling circulating cytokines associated with disease severity. Seventeen cytokines correlated with severity, of which 13 were pro-inflammatory, likely substantiating symptoms experienced by patients.
Ludovic Giloteaux (NY, USA) discussed alterations in the enteric bacterial and viral microbiome. He related his presentation to the many gastrointestinal symptoms experienced by patients with ME/CFS. He concluded that results of the study indicate dysbiosis of the gut microbiota. This suggests an increased incidence of microbial translocation, which may play a role in inflammatory symptoms. His group hypothesise that changes in the virome may contribute to intestinal inflammation and bacterial dysbiosis. There were more beneficial bacteria in the controls. Looking at this, 83% of patients could be correctly classified.
Session 2: Treatment studies and clinical practice
Olav Mella (Bergen, Norway) gave an overview of reflections on the rituximab studies. Efforts are directed at understanding the disease mechanisms and attempting to find a drug treatment. They feel it is an advantage to be able to correlate laboratory findings with clinical manifestations and response to interventional treatment. It is probable that symptoms will have a molecular counterpart, as well as patients having a genetic susceptibility. Results of immune manipulation with the drugs rituximab and cyclophosphamide make an immunological malfunction plausible.
They are now in a phase-three trial using rituximab, and results will be available in October 2017. He warned that we must not take results for granted. He asked the question, ‘Is the immune system the common factor?’ in patients being studied. There is NOT an immune deficiency. Allergies do change, and it is likely there is hyper-immunity. Not all immune therapies work.
The drug cyclophosphamide is an old drug used for immune suppression. It is being used in breast cancer for high-dose chemotherapy with stem-cell transplantation. In low doses it can enhance immune response in advanced cancers. There is now an ongoing Phase 2 trial for patients with ME/CFS. One infusion is given every four weeks, six times. The endpoints are as in the rituximab trials. There is then to be a 12-month observation period, looking at toxicity, symptom level, etc. Already symptoms are seen to be improving. In the short-term, toxicity is worse than in the cancer patients. One to two weeks after infusion, ME/CFS symptoms are worse. This is a broader acting drug than rituximab. Patients are all very similar in responses, with multiple body symptoms. It is likely that there is an inhibition of energy metabolism. A bi-product is lactate and its consequences. This blocks production of energy. New ATP is not produced. There is also flow-mediated dilatation of blood vessels, and a lack of nitric oxide is seen. The immune dysfunction may cause a mitochondrial defect.
He noted that the reaction to rituximab gives relief of all symptoms, indicating mitochondrial involvement.
Lucinda Bateman (Salt Lake City,USA) reported on the Synergy Trial for CFS — the phase two study uses low-dose methylphenindate plus mitochondrial support. (A previous trial reported by Blockmans had been positive). In the phase one trial there was 25% improvement in 87% of patients. In the phase two trial there was a strong placebo response noted, and although symptoms were decreased in the majority of ME/CFS patients, statistical significance was not achieved. Two subgroups had the greatest response: the severe group and those with both fatigue and pain. There were no obvious ill effects. There was a long list of nutrients in the support formula.
D.C. Shungu (New York, USA) used N-acetyl-cysteine (NAC) to alleviate cortical glutathione (GSH) deficit with a view to improving symptoms in ME/CFS. Previous studies had shown 36% deficit in occipital cortex glutathione — the primary tissue antioxidant. The latest study report provided evidence that NAC crosses the blood-brain barrier to spur the in situ synthesis and elevation of cortical GSH. Symptoms were ameliorated. Further studies will be needed to look at clinical efficacy, dosage and treatment duration of NAC.
Madison Sunnquist (Chicago, USA) presented a re-examination of the CBT theory of CFS. Her study concluded that those with ME/CFS do not reduce activity level due to illness beliefs. Exercise-based interventions also lack empirical justification and may not be appropriate.
David Patrick (Vancouver, Canada) discussed the potential for immunosignature assay to aid in classification and prediction of rituximab response in ME/CFS. Two hundred peptides were selected and 77.8% of blinded samples were correctly identified. Looking at the Norwegian rituximab trials, 200 peptides differentiated treatment responders from non-responders 92% of the time. This could help towards identifying patients likely to respond to treatment using B-cell depletion.
Session 3: Gulf War Illness
Nancy Klimas (Miami FL, USA) gave an excellent overview of the problems associated with Gulf War Illness (GWI) which first came to light following the war in 1990. The unexplained illness with multiple symptoms has many similarities and some differences when compared to ME/CFS.
This was a short war, but there was tremendous exposure to a number of issues: sand, heat, bugs, pesticides, oil fires, the wearing of chemical protection suits, pyridostigmine, sarin gas, etc. Pesticide exposure was highly likely and neurotoxins were predominant. One-third of returning veterans were ill, and many remained ill. There are complex scientific and clinical challenges, with similar controversies to ME/CFS. There are many overlaps. The prognosis is not well defined and the illness can last years. There is more post-exertional malaise in ME/CFS, but a lot can be learnt from GWI.
There are now many ongoing clinical trials, examples being coenzyme Q10, low-dose naltrexone, acupuncture, etc.
Kirsty Sullivan (Boston, USA) discussed brain-immune interactions in GWI, with reference to cytokines and cognition. She explained how cytokines release pain modulatory substances. 14% of participants were female. Fatigue, pain and cognition were compared to evaluations of 16 cytokines. There were significant plasma cytokine biomarker differences correlating with reduced performance on tasks of information processing and sustained attention.
Lubov Nathanson (Florida, USA) and his team had used a genomic approach to find the mechanisms of GWI pathobiology. They found an increased abundance of hypomethylated promoters of genes participating in signal transduction in the cells of those with GWI. There was enrichment in hypermethylated promoters of genes involved in apoptosis and cell differentiation. It is probable that DNA methylation is one of the factors regulating gene expression in GWI.
Travis Craddock (Florida, USA) has been using gene expression signatures to identify novel treatment strategies in GWI. There was correlation of gene expression patterns in 18 illnesses overlapping considerably with GWI. These were mainly brain, muscular and auto-immune disorders. Of the associated drugs, immunosuppressants currently used in rheumatoid arthritis, and hormone based therapies were identified as the best available candidates for treating GWI symptoms.
Session 4: Diagnosing difficult ME/CFS clinical cases
This session was chaired by Nancy Klimas (Florida, USA), and involved a panel of expert ME/CFS clinicians. Each participant presented a case for the panel to discuss. There was also considerable audience participation. The cases were many and varied, and the most frequently reported symptoms related to post-exertional malaise (PEM) and orthostatic intolerance (OI).
Session 5: CFS, SEID, ME case definitions — clinical vs research
This session was presented by Leonard Jason (Chicago, USA), with discussion by Lucinda Bateman (Salt Lake City, USA) and John Kaiser (San Francisco, USA). Fatigue is evident in 15–25% of the population at any one time, prolonged fatigue occurs in about 8% and chronic fatigue in 4–5%. This 4–5% is embraced by the Oxford criteria. The Fukuda criteria have much variability and not all the core symptoms are included. The Empiric criteria (2005) include psychiatric patients, e.g. depression fits these criteria. 2.2% of the population at any one time have a depressive disorder. The Canadian criteria require the inclusion of core symptoms and are more accurate. The International criteria include the core symptoms of PEM, cognitive problems and non-refreshing sleep. The IOM criteria include SEID, but exclusionary illnesses are required for completeness.
For naming the illness, M.E. (Myalgic Encephalomyelitis) is the term most preferred by patients. Many people still refer to the illness as CFS (Chronic Fatigue Syndrome). Internationally, the acronym ME/CFS is used widely now.
Lucinda Bateman feels there is a critical lack of firm diagnosis, with a lot of overlap into co-morbid conditions. The purpose of the IOM meeting was to improve diagnosis, with emphasis on objectively measureable features. The core criteria are listed. Other co-morbid illnesses may be present, and must be diagnosed and treated.
John Kaiser would like to see big pharmaceutical companies involved. The lack of consistent name, cause and criteria means a lack of interest from these organisations. The Fukuda criteria are not specific enough (and often include depressive patients). The Canadian criteria seem too complex and are not taken up by clinicians — there is a need to involve GPs. The IOM criteria are more specific and accurate because of inclusion of PEM. He felt CFS as the name of the illness is not appropriate and ME/CFS is now more commonly used.
Co-morbid illnesses tend to muddy the research — they are allowed in clinical practice, but not in research. Ideally, the same criteria should be used clinically and in research. An ICD-10 code is needed.