“The Poison Ivy Treatment” – An Intriguing CFS Case Study by Dr. Bell

by Dr. David S Bell, MD, FAAP*
February 2, 2011

This ME/CFS patient case history is one of 10 that Dr. David Bell included in his book Faces of CFS – Case Histories of Chronic Fatigue Syndrome, published in August, 2000.* Each case illustrates a different aspect of the illness that he observed in managing patients affected by the ‘Lyndonville Outbreak’ in New York, and none remains more fresh or intriguing than this one.

Reprinted with the kind permission of ProHealth: 2/2/11

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“This minor test is one of hundreds that prove to me that CFS is real and can be studied.” – David S Bell

I had been treating patients in my Lyndonville clinic for 10 years when, one day, I happened to pick up the chart of a patient whose name was unfamiliar to me. He was awaiting me in my examining room.

I quickly learned that Edwin Maxwell was the man who owned the beautiful farm on the Stillwell road. I had admired this farm every time I passed it on my way to the nearby hospital. The old barns were always maintained with care. I had come to expect an orderly procession of snowdrops, tulips and lilies on tended patches of lawn every spring and summer. I could see that a lovely stream ran through the rear of the property, which looked like a European forest – tidy, but natural, as wonderfully wild as anything could be and still be called a farm.

I also knew whoever tended this farm had a certain mysterious wisdom. If hay had just been cut on the Maxwell farm on a summer day, you could count on three sunny days to follow. Even the weather seemed to respect this farmer; his sixth sense was more reliable than any TV forecast.

I observed, as well, that there was no rush, no great urgency, to this farmer’s life. He tended his fields with patience, as if he knew that the earth would unfold its crops the way life unfolds its secrets – all in due time.

I liked the 45-year-old Edwin Maxwell immediately. He began our conversation by letting me know he was Dr. Wilson’s patient and would remain Dr. Wilson’s patient. He wanted to talk to me about this new disease I was studying, however, because he knew something about it.

He allowed as how he had every intention of paying for his visit, but he wanted me to understand that he was there to tell me something about CFS, not to be treated.

I settled back in my chair and waited. By then – the autumn of 1988 – there had been so much publicity about CFS that literally hundreds of people, some of them writing to me or calling me from the four corners of the earth, had already offered me their theories about what was causing CFS.

These theories of causation ranged from discarded plutonium at the nearby West Valley nuclear processing plant, to PCB’s in the salmon of Lake Ontario, to yeast in the intestinal tracts of sufferers. Then, as now, I listened to every one of these ideas with honest interest.

I continue to believe that, someday, someone would come up with the correct answer. Nevertheless, even then, these theories were growing pretty thin, sometimes bordering on the weird.

Edwin continued by stating that he, too, suffered from the disease I was studying. He was not looking for confirmation from me; in fact, his expression brooked no argument. He explained that he had been comparing notes on his symptoms with a number of his friends and neighbors who had CFS and were my patients.

I confess I was surprised: Most people with CFS show up in my clinic in a state of perplexed misery, wondering if I can tell them what is causing their joint pain and headaches and exhaustion. Edwin, in contrast, seemed to have a rare intellectual grasp on the disease.

When I tentatively asked him to tell me about his symptoms, he explained that the fatigue was the worst.

Three years before, he said, he could lift six, maybe seven, wagons of hay bales if he had to, and feed them onto the conveyor belt to the barn loft. He could plow and roll 17 acres of land in one day. Had for years – until three years ago. He added that he suffered from scratchy, sore throats. He had muscle pain, but he also pointed out that there was no reason, at his age, to have muscle pain. Hell, his father was still baling hay at 70.

He reported with obvious chagrin that he needed to wear sunglasses while he worked, even though he had always disliked sun glasses; they were something city people took to the beach.

So Edwin Maxwell could have CFS, I mused. Okay – now what? I waited.

“This spring,” Edwin said, “I had a lot of fields to plant in a short time.” He was choosing his words carefully. “The winters are okay, because it’s easy to cut the days down and get the extra rest. But not in the spring. There is so much to be done after the geese leave.”

Lyndonville happens to be on the migration pathway of Canadian geese. These great birds descend on the land for four to six weeks in the early spring, and when the fields begin to dry out from the winter snow, the geese head across the lake toward Canada. It is a time of great excitement in Lyndonville. The days begin lengthening in earnest now, and the geese are incredibly noisy.
You don’t even mind being woken at five in the morning by two thousand geese in the back cornfield. They leave when the ground begins to dry, the beginning of the plowing season.

“I remembered that the spring before,” Edwin continued, “I got poison ivy on my arm while cutting some brush in the back of the house. The poison ivy was nasty, but I noticed that the fatigue was better.

“I didn’t think much more about it. Then, this spring, just before plowing, I decided to pull up some poison ivy roots and rub them on my arms. Afterward, the itching was horrible, but my fatigue got better for about two full weeks. I could work just like before I got this disease, and I got all my planting done in time. But I noticed that as the poison ivy wore off, the fatigue came back.”

Edwin Maxwell was a careful observer of not only nature, but of himself, I realized. He asked for nothing in return. He was imparting some information to me, in case I was interested.

I was interested. New concepts about CFS either fit, or they did not fit, based on the selective “principles” I have developed over years of observation, principles framed by my experience. I realized immediately I had just heard a new “principle.”

Edwin’s revelation meant that the fatigue in CFS was not fixed; it could be variable. It could come and go, and was just a symptom; perhaps not even a necessary symptom. Theoretically, you could have CFS without being tired!

Consider the implications: if you were shot, or had a broken bone, little would be changed if you also acquired poison ivy; neither would exposure to the weed impact on your tuberculosis or your depression or your radiation sickness.

Poison ivy was an allergic response generated by the immune system, and localized at the point of exposure. Edwin was suggesting that this immune response – a sharp blip in the day to day functioning of the immune system, resulting from exposure to an allergen – might somehow diminish the fatigue in so-called “chronic fatigue syndrome.”

I had already discovered that among my CFS patients who were children, particularly, at least half had early childhood histories of either asthma, or allergies to various common substances.

I knew that there were a number of papers already published in the medical literature connecting CFS to medical histories of “atopic” illness, also known as allergies. A history of allergies appeared to be a risk factor for acquiring CFS. In fact, it was one of my established “principles” of the disease that a complex, if poorly understood, relationship existed between having CFS and allergies.

Yet, Edwin was telling me that if you applied an allergen to a small patch of an arm – if you localized an allergic response, in other words – you could make the fatigue in CFS go away while the allergic response lasted.

It didn’t really matter to me whether this held true for anyone else in the world. If it was true for one person with CFS, then it provided an hypothesis that could be tested in other CFS patients. The key was to learn whether this phenomenon represented a fundamental physiologic mechanism of the disease, or was just an interesting fluke.

If consistently true of all CFS sufferers, then any theory of the cause of CFS would have to hold an explanation as to why a poison ivy attack gave Edwin Maxwell an energy boost.

Sometimes when you think a great deal about something, you get so used to your own thoughts that they begin to seem dull. It takes someone else’s ideas to wake you up again. Edwin watched me as I struggled mentally to fit these new pieces of the puzzle together. He could see that I was taking his comments seriously.

I was ready to accept that fatigue need not be present for someone to have CFS.

I knew several people who lived in families where one member or more was thoroughly debilitated with full-blown CFS, and who suffered from severe intellectual problems along with other symptoms highly suggestive of CFS, even though they lacked the accompanying exhaustion. In fact, they had no more
than ordinary fatigue.

Could you jettison fatigue from the definition of the disease? I think you could, although this view would be unlikely to be published in a medical journal, especially since, even today, members of the scientific establishment are unwilling to agree that any of the symptoms of CFS are “real” and not psychiatric in origin. To persuade this same community that you can have what they call “chronic fatigue syndrome” without having “fatigue” would be next to impossible.

Nevertheless, the variability of fatigue – the idea that some people could have the disease without being tired – had become for me a defining principle. In truth, if this principle proved true, then the margins of CFS would begin to blur with the margins of attention deficit disorder (ADD), and other learning disabilities, especially in children. That was the population in which I most commonly saw patients with all the symptoms of CFS, minus one: fatigue.

Edwin Maxwell’s story got me thinking more intensively about the cause of the fatigue in CFS. I was intrigued that a natural substance, one manufactured by the body, called interleukin, might be the culprit.

While it may seem naive to look for a single substance responsible for fatigue, it did not seem a hopeless task. Scientists have been experimenting with one type of interleukin, interleukin-2 (or IL-2), as a therapy for several kinds of cancer. What researchers inevitably find, however, is that it doesn’t take very much IL-2 to induce symptoms in cancer patients that are almost as bad as the cancer.

Amidst the numerous side effects that include confusion and mood changes, IL-2 also causes profound fatigue when it is administered as a drug therapy.

Some months before Edwin Maxwell’s visit to my clinic, I had published a scientific paper with a collaborator, internal medicine specialist Paul Cheney, in which we reported that children and adults with CFS had startlingly high levels of the receptor molecule for IL-2. These levels were so high that it implied that the chemical IL-2 could be causing the fatigue and other symptoms of the disease.(1)

I realized that Edwin – if he was willing – could help me test my nascent theory that measuring IL-2 levels might be a way to quantitate the fatigue in CFS in a laboratory. He was willing.

I told him we would take blood samples from him when he was exhausted and measure IL-2 receptor. Then, we would apply poison ivy to his arm and wait until the fatigue improved. When the poison ivy kicked in and the fatigue went away, we would draw more blood. I suggested we do this three times, to be sure of our results.

Edwin liked my idea. It made sense to him. One sunny afternoon at the end of July that summer, I drew blood from Edwin’s arm during a “normal” period when the farmer’s exhaustion was pretty severe. I asked him to maintain a kind of symptom severity journal, as well, which required him to rate the severity of fatigue and 11 other symptoms on a scale of one to ten, with ten being the worst.

After I drew his blood, Edwin himself rubbed poison ivy on his arm. A week later I met him in the emergency room where they kept a camera and photographed the rash on his arms. A few days later, Edwin’s fatigue had subsided substantially, and I drew another sample of blood. We waited for the good effects of the poison ivy to wear off. Then we repeated the entire process.

We did not get to the third trial because by then Edwin had begun to dread the effects of the poison ivy as much as he had grown to dread the fatigue. He begged off, and I respectfully complied with his wishes. I already thought him very brave to offer himself up to medical science as he had done.

Also, the emergency ward staff was beginning to look at me in a funny way because I kept photographing the poison ivy someone was giving himself. Ah, science……

Ours was never anything more than an informal experiment, one that ended somewhat prematurely, but its results were provocative.

Just as Edwin had reported, his fatigue, as well as his other symptoms, were diminished when he was suffering from acute poison ivy. Somehow, this classic allergic response mitigated his most debilitating symptoms: fatigue, compromised intellectual capabilities, and physical pain.

However, the results failed to confirm beyond all doubt my theory about the relationship between IL-2 levels in the blood and fatigue. The results did suggest that fatigue severity was not just a coincidence, the normal ups and downs of CFS symptoms. It was intriguing to speculate that this relationship could even be someday turned into an effective treatment of the symptoms.

Unfortunately, the options are not that good. Edwin preferred the regular CFS symptoms to severe poison ivy symptoms. Maybe it’s not such a great treatment.

Medical science is cumbersome. Hints, such as the hints produced by this experiment, cannot be published in medical journals without real proof. And to conduct a proper experiment takes a great deal of time, money and paperwork, all of which are in short supply for the clinician. But the most frustrating part is the inability of clinicians to communicate to those able to do real experiments that CFS is real and must be taken seriously.

Two weeks ago I attended a neurology conference and CFS was dismissed by the lecturer as a minor psychosomatic nuisance for which there were no tests. The real problem is that academics and governmental public health personnel refuse to put aside their biases and look for the proofs. They seem content to criticize experiments like Edwin’s as incomplete. And of course they are correct.

But Edwin’s poison ivy treatment was over 10 years ago [now more than 20], and still nothing has come from it. This minor test is one of hundreds that prove to me that CFS is real and can be studied. From a scientific perspective, the relationship between the debilitating symptoms of CFS and allergic response is fascinating. I have been naive to think that it would be fascinating for others.

The misperception that CFS is psychosomatic comes only from scientists’ inability to look beyond their psychosomatic biases and look for the proofs.

Edwin doesn’t care, and in this respect he is unique. He gets on with his life, tends the springtime garden with care, manages to get the hay in every summer. He is able to accept the presence of symptoms as he accepts hail which damages the apple crop. And he is lucky, his symptoms are relatively mild and he can ration his time. If he worked in a factory assembly line with rigid hours, he would not be as lucky.

I rarely see Edwin now. Sometimes, while driving by his beautiful farm on the Stillwell road on my way to the hospital, I wave to him in the flower bed, or when he is putting the tractor into the barn. He is busy getting on with the business at hand, he doesn’t have time to feel sick.

– Dr. David S Bell, MD, Lyndonville, New York, August 15, 2000
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1. Citation: “Interleukin-2 and the Chronic Fatigue Syndrome,”  Annals of Internal Medicine, Feb 15, 1989, by Paul R. Cheney, MD, PhD; Susan E. Dorman; David S. Bell, MD.

* This article is excerpted with kind permission from Dr. Bell’s classic book Faces of CFS – Case Histories of Chronic Fatigue Syndrome; © David S Bell, MD, 2000.

Killer cell immunoglobulin-like receptor (KIR) alleles suggested to be associated with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic and debilitating disease with unknown cause. Involvement of infection and immune dysregulation has been suggested, including changes in immune cell subsets and abnormal functions of natural killer (NK) cells.

The regulatory NK cell receptors, killer cell immunoglobulin-like receptors (KIR) have previously been investigated in small cohorts of ME/CFS patients with conflicting results regarding gene content. Here, we studied KIR genes also at the allelic level using high-resolution sequencing, in 418 ME/CFS patients and 473 healthy controls.

Human leukocyte antigen (HLA) class I genotype data were included for KIR ligand annotation. Our healthy control data represent KIR frequencies for a Norwegian population, which have not previously been reported. We found no association between ME/CFS and KIR gene content or copy number variations. However, our data suggested that specific KIR alleles at loci encoding inhibitory receptors were associated with ME/CFS, which was further supported by allelic haplotype analyses.

Three alleles were more frequent in patients, i.e. KIR3DL3*002 (OR = 1.43, 95 %CI (1.09-1.86), p = 0.009), KIR3DL1*020 (OR = 2.20, 95 %CI (1.19-4.06), p = 0.01) and KIR3DL2*009 (OR = 1.56, 95 %CI (1.09-2.23), p = 0.01), while two alleles had a reduced patient frequency, i.e. KIR3DL3*013 (OR = 0.60, 95 %CI (0.42-0.86), p = 0.005) and KIR3DL2*010 (OR = 0.46, 95 %CI (0.30-0.71), p = 0.0005). Our data support an involvement of NK cells in ME/CFS.

Source: Ramadan DJ, Kichula KM, Tao S, Porfilio T, Lande A, Fluge Ø, Mella O, Strand EB, Saugstad OD, Norman PJ, Lie BA, Viken MK. Killer cell immunoglobulin-like receptor (KIR) alleles suggested to be associated with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Brain Behav Immun. 2025 Aug 31:106098. doi: 10.1016/j.bbi.2025.106098. Epub ahead of print. PMID: 40897283. https://www.sciencedirect.com/science/article/pii/S0889159125003332 (Full text)

Heightened innate immunity may trigger chronic inflammation, fatigue and post-exertional malaise in ME/CFS

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by unexplained fatigue, post-exertional malaise (PEM), and cognitive dysfunction. ME/CFS patients often report a prodrome consistent with infection. We present a multi-omics analysis based on plasma metabolomic and proteomic profiling, and immune responses to microbial stimulation, before and after exercise.

We report evidence of an exaggerated innate immune response after exposures to microbial antigens; impaired energy production involving the citric acid cycle, beta-oxidation of fatty acids, and urea cycle energy production from amino acids; systemic inflammation linked with lipid abnormalities; disrupted extracellular matrix homeostasis with release of endogenous ligands that promote inflammation; reduced cell-cell adhesion and associated gut dysbiosis; complement activation; redox imbalance reflected by disturbances in copper-dependent antioxidant pathways and dysregulation of the tryptophan-serotonin-kynurenine pathways.

Many of these underlying abnormalities worsened following exercise in ME/CFS patients, but not in healthy subjects; many abnormalities reinforced each other and several were correlated with the intensity of symptoms. Our findings may inform targeted therapeutic interventions for ME/CFS and PEM.

Source: Che X, Ranjan A, Guo C, Zhang K, Goldsmith R, Levine S, Moneghetti KJ, Zhai Y, Ge L, Mishra N, Hornig M, Bateman L, Klimas NG, Montoya JG, Peterson DL, Klein SL, Fiehn O, Komaroff AL, Lipkin WI. Heightened innate immunity may trigger chronic inflammation, fatigue and post-exertional malaise in ME/CFS. medRxiv [Preprint]. 2025 Jul 24:2025.07.23.25332049. doi: 10.1101/2025.07.23.25332049. PMID: 40778181; PMCID: PMC12330418. https://pmc.ncbi.nlm.nih.gov/articles/PMC12330418/ (Full text available as PDF file)

Exploring the Joint Potential of Inflammation, Immunity, and Receptor-Based Biomarkers for Evaluating ME/CFS Progression

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating chronic condition with no identified diagnostic biomarkers to date. Its prevalence is as high as 0.89% according to metastudies, with a quarter of patients bed-or home-bound, which presents a serious public health challenge. Investigations into the inflammation-immunity axis is encouraged by links to outbreaks and disease waves. Recently, research of our group revealed that antibodies to beta2adrenergic (anti-β2AdR) and muscarinic acetylcholine (anti-M4) receptors demonstrate sensitivity to the progression of ME/CFS.

The purpose of this study is to investigate the joint potential of inflammatome -characterized by interferon (IFN)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-2, IL-21, Il-23, IL-6, IL-17A, Activin-B, immunome (IgG1, IgG2, IgG3, IgG4, IgM, IgA) and receptor-based biomarkers (anti-M3, anti-M4, anti-β2AdR) determined for evaluating ME/CFS progression, and to identify an optimal selection for future validation in prospective clinical studies.

Methods: A dataset was used originating from 188 persons, including 54 healthy controls, 30 patients classified as “mild” by severity, 73 as “moderate,” and 31 as “severe,” clinically assessed by Fukuda/CDC 1994 and International consensus criteria. Markers characterizing inflammatome, immunome, and receptor-based biomarkers were determined in blood plasma via ELISA and multiplex methods.

Statistical analysis was done via correlation analysis, principal component, and linear discriminant analysis, and random forest classification; inter-group differences tested via nonparametric Kruskal-Wallis H test followed by the two-stage linear step-up procedure of Benjamini, Krieger, and Yekutieli, and via Mann-Whitney U test.

The association between inflammatome and immunome markers is broader and stronger (coupling) in severe group. Principal component factoring separate components affiliated with inflammatome, immunome, and receptor biomarkers. Random forest modeling demonstrates an out-of-box accuracy for splitting healthy/with condition groups of over 90%, and of 45% for healthy/severity groups. Classifiers with the highest potential are anti-β2AdR, anti-M4, IgG4, IL-2, and IL-6.

Discussion: Association between inflammatome and immunome markers is a candidate for controlled clinical study of ME/CFS progression markers that could be used for treatment individualization. Thus, coupling effects between inflammation and immunity have a potential for the identification of prognostic factors in the context of ME/CFS progression mechanism studies.

Source: Uldis Berkis, Simons Svirskis, Angelika Krumina, Sabine Gravelsina, Anda Vilmane, Diana Araja, Zaiga Nora-Krukle, Modra Murovska. Exploring the Joint Potential of Inflammation, Immunity, and Receptor-Based Biomarkers for Evaluating ME/CFS Progression. Frontiers in Immunology. Sec. Autoimmune and Autoinflammatory Disorders : Autoimmune Disorders. Volume 14- 2023.  https://www.frontiersin.org/articles/10.3389/fimmu.2023.1294758/abstract

Sex differences in vascular endothelial function related to acute and long COVID-19

Abstract:

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has been at the forefront of health sciences research since its emergence in China in 2019 that quickly led to a global pandemic. As a result of this research, and the large numbers of infected patients globally, there were rapid enhancements made in our understanding of Coronavirus disease 2019 (COVID-19) pathology, including its role in the development of uncontrolled immune responses and its link to the development of endotheliitis and endothelial dysfunction.

There were also some noted differences in the rate and severity of infection between males and females with acute COVID. Some individuals infected with SARS-CoV-2 also experience long-COVID, an important hallmark symptom of this being Myalgic Encephalomyelitis-Chronic Fatigue Syndrome (ME-CFS), also experienced differently between males and females.

The purpose of this review is to discuss the impact of sex on the vasculature during acute and long COVID-19, present any link between ME-CFS and endothelial dysfunction, and provide evidence for the relationship between ME-CFS and the immune system. We also will delineate biological sex differences observed in other post viral infections and, assess if sex differences exist in how the immune system responds to viral infection causing ME-CFS.

Source: Kayla KA, Bédard-Matteau J, Rousseau S, Tabrizchi R, Noriko D. Sex differences in vascular endothelial function related to acute and long COVID-19. Vascul Pharmacol. 2023 Dec 1:107250. doi: 10.1016/j.vph.2023.107250. Epub ahead of print. PMID: 38043758. https://www.sciencedirect.com/science/article/abs/pii/S1537189123001106 (Full text)

Comparison of T-cell Receptor Diversity of people with Myalgic Encephalomyelitis versus controls

Abstract:

Objective: Myalgic Encephalomyelitis (ME; sometimes referred to as Chronic Fatigue Syndrome or CFS) is a chronic disease without laboratory test, detailed aetiological understanding or effective therapy. Its symptoms are diverse, but it is distinguished from other fatiguing illnesses by the experience of post-exertional malaise, the worsening of symptoms even after minor physical or mental exertion. Its frequent onset after infection might indicate that it is an autoimmune disease or that it arises from abnormal T-cell activation.

Results: To test this hypothesis, we sequenced the genomic loci of a/d, b and g T-cell receptors (TCR) from 40 human blood samples from each of four groups: severely affected people with ME/CFS; mildly or moderately affected people with ME/CFS; people diagnosed with Multiple Sclerosis, as disease controls; and, healthy controls. Seeking to automatically classify these individuals’ samples by their TCR repertoires, we applied P-SVM, a machine learning method. However, despite working well on a simulated data set, this approach did not partition samples into the four subgroups, beyond what was expected by chance alone.  Our findings do not support the hypothesis that blood samples from people with ME/CFS frequently contain altered T-cell receptor diversity.

Source: Joshua J Dibble, Ben Ferneyhough, Matthew Roddis et al. Comparison of T-cell Receptor Diversity of people with Myalgic Encephalomyelitis versus controls, 19 July 2023, PREPRINT (Version 1) available at Research Square [https://doi.org/10.21203/rs.3.rs-3164397/v1]  https://www.researchsquare.com/article/rs-3164397/v1 (Full text)

Biomarkers for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): a systematic review

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a multifaceted condition that affects most body systems. There is currently no known diagnostic biomarker; instead, diagnosis is dependent on application of symptom-based case criteria following exclusion of any other potential medical conditions. While there are some studies that report potential biomarkers for ME/CFS, their efficacy has not been validated. The aim of this systematic review is to collate and appraise literature pertaining to a potential biomarker(s) which may effectively differentiate ME/CFS patients from healthy controls.

Methods: This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Cochrane review guidelines. PubMed, Embase and Scopus were systematically searched for articles containing “biomarker” and “ME/CFS” keywords in the abstract or title and if they included the following criteria: (1) were observational studies published between December 1994 and April 2022; (2) involved adult human participants; (3) full text is available in English (4) original research; (5) diagnosis of ME/CFS patients made according to the Fukuda criteria (1994), Canadian Consensus Criteria (2003), International Consensus Criteria (2011) or Institute of Medicine Criteria (2015); (6) study investigated potential biomarkers of ME/CFS compared to healthy controls. Quality and Bias were assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Case Control Studies.

Results: A total of 101 publications were included in this systematic review. Potential biomarkers ranged from genetic/epigenetic (19.8%), immunological (29.7%), metabolomics/mitochondrial/microbiome (14.85%), endovascular/circulatory (17.82%), neurological (7.92%), ion channel (8.91%) and physical dysfunction biomarkers (8.91%). Most of the potential biomarkers reported were blood-based (79.2%). Use of lymphocytes as a model to investigate ME/CFS pathology was prominent among immune-based biomarkers. Most biomarkers had secondary (43.56%) or tertiary (54.47%) selectivity, which is the ability for the biomarker to identify a disease-causing agent, and a moderate (59.40%) to complex (39.60%) ease-of-detection, including the requirement of specialised equipment.

Conclusions: All potential ME/CFS biomarkers differed in efficiency, quality, and translatability as a diagnostic marker. Reproducibility of findings between the included publications were limited, however, several studies validated the involvement of immune dysfunction in the pathology of ME/CFS and the use of lymphocytes as a model to investigate the pathomechanism of illness. The heterogeneity shown across many of the included studies highlights the need for multidisciplinary research and uniform protocols in ME/CFS biomarker research.

Source: Maksoud R, Magawa C, Eaton-Fitch N, Thapaliya K, Marshall-Gradisnik S. Biomarkers for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): a systematic review. BMC Med. 2023 May 24;21(1):189. doi: 10.1186/s12916-023-02893-9. PMID: 37226227; PMCID: PMC10206551. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10206551/ (Full text)

Natural killer cytotoxicity in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): a multi-site clinical assessment of ME/CFS (MCAM) sub-study

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a multisystem illness characterized by substantial reduction in function accompanied by profound unexplained fatigue not significantly relieved by rest, post-exertional malaise, and other symptoms. Reduced natural killer (NK) cell count and cytotoxicity has been investigated as a biomarker for ME/CFS, but few clinical laboratories offer the test and multi-site verification studies have not been conducted.

Methods: We determined NK cell counts and cytotoxicity in 174 (65%) ME/CFS, 86 (32%) healthy control (HC) and 10 (3.7%) participants with other fatigue associated conditions (ill control [IC]) from the Multi-Site Clinical Assessment of ME/CFS (MCAM) study using an assay validated for samples shipped overnight instead of testing on day of venipuncture.

Results: We found a large variation in percent cytotoxicity [mean and (IQR) for ME/CFS and HC respectively, 34.1% (IQR 22.4-44.3%) and 33.6% (IQR 22.9-43.7%)] and no statistically significant differences between patients with ME/CFS and HC (p-value = 0.79). Analysis stratified on illness domain measured with standardized questionnaires did not identify an association of NK cytotoxicity with domain scores. Among all participants, NK cytotoxicity was not associated with survey results of physical and mental well-being, or health factors such as history of infection, obesity, smoking, and co-morbid conditions.

Conclusion: These results indicate this assay is not ready for clinical implementation and studies are needed to further explore immune parameters that may be involved in the pathophysiology of ME/CFS.

Source: Querec TD, Lin JS, Chen Y, Helton B, Kogelnik AM, Klimas NG, Peterson DL, Bateman L, Lapp C, Podell RN, Natelson BH, Unger ER; MCAM Study Group. Natural killer cytotoxicity in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): a multi-site clinical assessment of ME/CFS (MCAM) sub-study. J Transl Med. 2023 Apr 3;21(1):242. doi: 10.1186/s12967-023-03958-2. PMID: 37013608. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03958-2 (Full text)

Investigating the Genetic and Immunological Aetiology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

This thesis describes two investigations into the disease Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), specifically its genetic aetiology and immune system alterations.

The first study investigated the genetic basis of ME/CFS using Genome-wide Association Studies (GWAS) by attempting to replicate and extend results previously found using UK Biobank cohort data. GWAS attempt to identify associations between DNA variants and phenotypes. T his GWAS was novel, conducted on new phenotypes constructed by combining those in the most up-to-date UK Biobank data release. A new, previously unseen, genome-wide significant association was found on chromosome 6 for males with ME/CFS within the gene PDE10A. Further results were not genome-wide significant, but many were suggestive and hence independent replication may justify further research.

A previous analysis on the UK Biobank cohort had identified an indicative association in females between variants around the SLC25A15 gene at genome-wide significance. I adopted a hypothesis that the dietary protein intake of people with the CFS risk variants would be lower than those with the alternative alleles, due to potentially reduced production of mitochondrial ornithine transporter 1 (ORNT1). However, this association with dietary protein intake was not supported by UK Biobank data.

Additionally, I investigated associations between the human leukocyte antigen (HLA) alleles and the ME/CFS phenotype using UK Biobank data. Associations between alleles within the HLA-C and -DQB1 genes had previously been found in a cohort of Norwegian people with ME/CFS, and my goal was to seek replication of these results in a larger dataset. None of the associations found in the UK Biobank proved to be genome-wide significant.

In my second study I investigated the use of T-cell clonal diversity as a potential biomarker for ME/CFS. This project used cells from CureME Biobank samples in collaboration with Systems Biology Laboratory (SBL). I developed a data analysis pipeline to analyse T-cell receptor (TCR) genomic DNA data based on the best practices currently used in the fields of immunology and mathematical biology. This approach used a mathematical notion of entropy as a measure for the diversity of TCR repertoires, in this way combining all of the most commonly used metrics in mathematical biology. When combined, these measures form a profile for each repertoire, a set of which can be sorted using a machine learning algorithm to partition the repertoires into subgroups.

My hypothesis was that the T-cell clonal expansion of people with ME/CFS would be greater than for healthy controls, and comparable to disease (multiple sclerosis) controls. Although this method was able to effectively classify TCR chains using simulated data, results from experimentally-derived data did not support the hypothesis, with the most effective classifications for both CD4+ and CD8+ cells failing to pass corrections for multiple hypothesis significance testing.

Lay summary

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a disease that affects millions of people around the world. Very little is understood about the cause or progression of the disease, and there is no known cure. At present, there is also no reliable clinical test to determine whether a person has ME/CFS.

This thesis explores the potential for a genetic or immunological basis for ME/CFS, with the goal to eventually find a biomarker that could be used in diagnosis.

The first part of this thesis investigates whether genetic variants are more (or less) common among those with ME/CFS than in the general population. In particular, the region of the genome that encodes immune system proteins was of interest, as previous studies have shown associations between this region and the disease.

Using strict statistical thresholds, none of the previously found associations were replicated. However, one new association was found, with the gene PDE10A, which is implicated in central nervous system diseases, such as Parkinsons and Huntingtons disease. This association has never been seen before, and would require replication in a new cohort before its role in ME/CFS could be confirmed. However, it represents a promising avenue for new research.

The second part of this thesis investigates T-cells. These are highly specialised immune cells in the blood, each of which targets an antigen (foreign substance) such as from a virus. When a T-cell recognises this antigen, it clones itself repeatedly. This clonal expansion is measurable, and can serve as evidence of immune system activation.

My hypothesis was that this immune signature could be used to distinguish people with ME/CFS from healthy controls and others diagnosed with another disease.

I used a mathematical measure of diversity and a machine learning method to sort their immune profiles into groups. However, the pattern of immune activation was not sufficiently clear to provide consistent classification. Hence, the role of the immune system in ME/CFS is still unclear, and the utility of this method as a diagnostic biomarker is not proved.

Source: Joshua James Dibble. Investigating the Genetic and Immunological Aetiology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. PhD Thesis [University of Edinburgh]  https://era.ed.ac.uk/bitstream/handle/1842/39763/DibbleJJ_2022.pdf?sequence=1&isAllowed=y (Full text)

Stress-Induced Transcriptomic Changes in Females with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Reveal Disrupted Immune Signatures

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic, complex multi-organ illness characterized by unexplained debilitating fatigue and post-exertional malaise (PEM), which is defined as a worsening of symptoms following even minor physical or mental exertion. Our study aimed to evaluate transcriptomic changes in ME/CFS female patients undergoing an exercise challenge intended to precipitate PEM.
Our time points (baseline before exercise challenge, the point of maximal exertion, and after an exercise challenge) allowed for the exploration of the transcriptomic response to exercise and recovery in female patients with ME/CFS, as compared to healthy controls (HCs). Under maximal exertion, ME/CFS patients did not show significant changes in gene expression, while HCs demonstrated altered functional gene networks related to signaling and integral functions of their immune cells.
During the recovery period (commonly during onset of PEM), female ME/CFS patients showed dysregulated immune signaling pathways and dysfunctional cellular responses to stress. The unique functional pathways identified provide a foundation for future research efforts into the disease, as well as for potential targeted treatment options.
Source: Van Booven DJ, Gamer J, Joseph A, Perez M, Zarnowski O, Pandya M, Collado F, Klimas N, Oltra E, Nathanson L. Stress-Induced Transcriptomic Changes in Females with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Reveal Disrupted Immune Signatures. International Journal of Molecular Sciences. 2023; 24(3):2698. https://doi.org/10.3390/ijms24032698 https://www.mdpi.com/1422-0067/24/3/2698 (Full text)