Herpesviruses serology distinguishes different subgroups of patients from the United Kingdom Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Biobank, by Tiago Dias Domingues, Anna D Grabowska, Ji-Sook Lee, Jose Ameijeiras-Alonso, Francisco Westermeier, Carmen Scheibenbogen, Jacqueline M Cliff, Luis Nacul, Eliana M Lacerda, Helena Mourino, Nuno Sepulveda in Frontiers in Medicine (Lausanne) Vol 8, p 686736, July 5, 2021 [doi.org/10.3389/fmed.2021.686736]
The evidence of an association between Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and chronic herpesviruses infections remains inconclusive. Two reasons for the lack of consistent evidence are the large heterogeneity of the patients’ population with different disease triggers and the use of arbitrary cutoffs for defining seropositivity.
Serology is the scientific study of serum (a component of blood) and other body fluids. (from Wikipedia)
In this work we re-analyzed previously published serological data related to 7 herpesvirus antigens. Patients with ME/CFS were subdivided into four subgroups related to the disease triggers:
- S0-42 patients who did not know their disease trigger;
- S1-43 patients who reported a non-infection trigger;
- S2-93 patients who reported an infection trigger, but that infection was not confirmed by a lab test; and
- S3-48 patients who reported an infection trigger and that infection was confirmed by a lab test.
In accordance with a sensitivity analysis, the data were compared to those from 99 healthy controls allowing the seropositivity cutoffs to vary within a wide range of possible values. We found a negative association between S1 and seropositivity to Epstein-Barr virus (VCA and EBNA1 antigens) and Varicella-Zoster virus using specific seropositivity cutoff. However, this association was not significant when controlling for multiple testing.
We also found that S3 had a lower seroprevalence to the human cytomegalovirus when compared to healthy controls for all cutoffs used for seropositivity and after adjusting for multiple testing using the Benjamini-Hochberg procedure. However, this association did not reach statistical significance when using Benjamini-Yekutieli procedure.
In summary, herpesviruses serology could distinguish subgroups of ME/CFS patients according to their disease trigger, but this finding could be eventually affected by the problem of multiple testing.
This new finding was only possible due to the stratification of patients according to a question related to the occurrence of an infection at disease onset together with a sensitivity analysis of the seropositivity cutoff used. Patients’ stratification or subtyping was performed in line with past recommendations for ME/CFS research (28). Following this recommendation, we previously performed an immunological investigation based on a stratification of ME/CFS patients according to the severity of their symptoms (32). By using this stratification, we showed perturbations in the T-cell compartment, namely, in effector CD8+ T cells and in the mucosal-associated invariant T cells.
In another study using similar stratification of the samples from the UKMEB, the levels of the cellular stress biomarker GDF15 were found to be increased in severely affected patients at different time points (45). We speculate that other immunological perturbations could be detected if our alternative stratification could have been used. This investigation will be carried out in the near future.
…As final remarks, we should also note that cutoffs for detecting associations between herpesviruses and ME/CFS might vary from one lab to another and with the serological kits used. In addition, a high cutoff for the data might not define seropositivity per se, but rather a high antibody response whose detection could be the primary objective of the analysis (30, 31). The use of a high cutoff is also in accordance with a modeling approach where seropositivity might be subdivided into different levels (60–62).
Therefore, our sensitivity-like approach seems to have the capacity to detect further serological associations beyond the ones based on the classical seroprevalence. Such a capacity could increase the chance of reaching scientific reproducibility. We then recommend the routine use of this approach in future serological investigations of ME/CFS.