EBV/HHV-6A dUTPases contribute to Myalgic Encephalomyelitis/Chronic-Fatigue-Syndrome pathophysiology by enhancing TFH cell differentiation and extrafollicular activities

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a chronic, debilitating multisystem illness of unknown etiology for which there is no cure and no diagnostic tests available. Despite increasing evidence implicating EBV and human herpesvirus-6A (HHV-6A) as potential causative infectious agents in a subset of ME/CFS patients, there are few mechanistic studies to address a causal relationship.

In this study we examined a large ME/CFS cohort (n=351) and 77 controls and demonstrate a significant increase in activin A and IL-21serum levels, which correlated with seropositivity for antibodies to the EBV and HHV-6 protein deoxyuridine-triphosphate nucleotidohydrolase (dUTPase), but not CXCL13. These cytokines are critical for T follicular helper (TFH) cell differentiation, generation of high-affinity antibodies and long-lived plasma cells. Notably, ME/CFS serum was sufficient to drive TFH cell differentiation via an activin A-dependent mechanism.

The lack of simultaneous CXCL13 increase with IL-21 indicates impaired TFH-function in ME/CFS. In vitro studies revealed that virus-dUTPases strongly induced activin A secretion while in vivo, EBV-dUTPase induced the formation of splenic marginal zone B and invariant NKTFH cells. Altogether, our data indicate abnormal germinal center (GC) activity in ME/CFS subjects and highlight a mechanism by which EBV and HHV6-dUTPases may alter GC and extrafollicular Ab responses.

Source: Cox BS, Alharshawi K, Mena-Palomo I, Lafuse WP, Ariza ME. EBV/HHV-6A dUTPases contribute to Myalgic Encephalomyelitis/Chronic-Fatigue-Syndrome pathophysiology by enhancing TFH cell differentiation and extrafollicular activities. JCI Insight. 2022 Apr 28:e158193. doi: 10.1172/jci.insight.158193. Epub ahead of print. PMID: 35482424. https://pubmed.ncbi.nlm.nih.gov/35482424/

Potential of Activin B as a Clinical Biomarker in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

Reliable serum biomarkers are of immense need for diagnostic purposes of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)-a disabling and complex disease for which diagnosis is mainly based on clinical symptoms. The aim of this study was to evaluate a possible diagnostic potential of activin B by directly comparing 134 cases of ME/CFS with 54 healthy controls.

Analyses of human activin B level in plasma samples were performed using a validated human activin B ELISA assay. The results of the study show that activin B levels did not differ statistically significantly between ME/CFS patients and healthy controls (p = 0.6511). No gender or age-related differences in activin B levels were observed in the ME/CFS group and healthy controls. The level of activin B tended to decrease with increasing visual analogue scale score (r = -0.2004; p = 0.5085) nevertheless the results obtained so far does not support the clinical utility of activin B as a biomarker for ME/CFS.

Source: Gravelsina S, Nora-Krukle Z, Vilmane A, Svirskis S, Vecvagare K, Krumina A, Murovska M. Potential of Activin B as a Clinical Biomarker in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Biomolecules. 2021 Aug 11;11(8):1189. doi: 10.3390/biom11081189. PMID: 34439855. https://pubmed.ncbi.nlm.nih.gov/34439855/

Rethinking ME/CFS Diagnostic Reference Intervals via Machine Learning, and the Utility of Activin B for Defining Symptom Severity

Abstract:

Biomarker discovery applied to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), a disabling disease of inconclusive aetiology, has identified several cytokines to potentially fulfil a role as a quantitative blood/serum marker for laboratory diagnosis, with activin B a recent addition. We explored further the potential of serum activin B as a ME/CFS biomarker, alone and in combination with a range of routine test results obtained from pathology laboratories.

Previous pilot study results showed that activin B was significantly elevated for the ME/CFS participants compared to healthy (control) participants. All the participants were recruited via CFS Discovery and assessed via the Canadian/International Consensus Criteria. A significant difference for serum activin B was also detected for ME/CFS and control cohorts recruited for this study, but median levels were significantly lower for the ME/CFS cohort.

Random Forest (RF) modelling identified five routine pathology blood test markers that collectively predicted ME/CFS at ≥62% when compared via weighted standing time (WST) severity classes. A closer analysis revealed that the inclusion of activin B to the panel of pathology markers improved the prediction of mild to moderate ME/CFS cases. Applying correct WST class prediction from RFA modelling, new reference intervals were calculated for activin B and associated pathology markers, where 24-h urinary creatinine clearance, serum urea and serum activin B showed the best potential as diagnostic markers. While the serum activin B results remained statistically significant for the new participant cohorts, activin B was found to also have utility in enhancing the prediction of symptom severity, as represented by WST class.

Source: Lidbury BA, Kita B, Richardson AM, Lewis DP, Privitera E, Hayward S, de Kretser D, Hedger M. Rethinking ME/CFS Diagnostic Reference Intervals via Machine Learning, and the Utility of Activin B for Defining Symptom Severity. Diagnostics (Basel). 2019 Jul 19;9(3). pii: E79. doi: 10.3390/diagnostics9030079. https://www.mdpi.com/2075-4418/9/3/79 (Full article)

Activin B is a novel biomarker for chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) diagnosis: a cross sectional study

Abstract:

Background: Investigations of activin family proteins as serum biomarkers for chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME). CFS/ME is a disease with complex, wide-ranging symptoms, featuring persistent fatigue of 6 months or longer, particularly post exertion. No definitive biomarkers are available.

Methods: A cross-sectional, observational study of CFS/ME patients fulfilling the 2003 Canadian Consensus Criteria, in parallel with healthy non-fatigued controls, was conducted. Comparisons with a previously defined activin reference population were also performed. For the total study cohort the age range was 18–65 years with a female: male participant ratio of greater than 3:1. All participants were assessed via a primary care community clinic. Blood samples were collected for pathology testing after physical examination and orthostatic intolerance assessment. Cytokines, activin A, activin B and follistatin were also measured in sera from these samples. All data were compared between the CFS/ME and control cohorts, with the activins and follistatin also compared with previously defined reference intervals.

Results: Serum activin B levels for CFS/ME participants were significantly elevated when compared to the study controls, as well as the established reference interval. Serum activin A and follistatin were within their normal ranges. All routine and special pathology markers were within the normal laboratory reference intervals for the total study cohort, with no significant differences detected between CFS/ME and control groups. Also, no significant differences were detected for IL-2, IL-4, IL-6, IL-10, IL-17A, TNF or IFN-gamma.

Conclusion: Elevated activin B levels together with normal activin A levels identified patients with the diagnostic symptoms of CFS/ME, thus providing a novel serum based test. The activins have multiple physiological roles and capture the diverse array of symptoms experienced by CFS/ME patients.

 

Source: Brett A. Lidbury, Badia Kita, Donald P. Lewis, Susan Hayward, Helen Ludlow, Mark P. Hedger and David M. de Kretser. Activin B is a novel biomarker for chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) diagnosis: a cross sectional study. Journal of Translational Medicine 201715:60, DOI: 10.1186/s12967-017-1161-4 http://translational-medicine.biomedcentral.com/articles/10.1186/s12967-017-1161-4 (Full article)