Researchers
Nuno Sepúlveda, João Malato, Franziska Sotzny, Anna D Grabowska, André Fonseca, Clara Cordeiro, Luís Graça, Przemyslaw Biecek, Uta Behrends, Josef Mautner, Francisco Westermeier, Eliana M Lacerda & Carmen Scheibenbogen
Institutes
Warsaw University of Technology, Poland; Charité – Universitätsmedizin Berlin, Germany; London School of Hygiene and Tropical Medicine, UK; and others
Publication
Frontiers in Medicine, 2022 June 24; 9:921101
Key findings
- Epstein-Barr virus (EBV) infection is commonly reported at the onset of ME/CFS, but could antibodies against EBV serve as biomarkers of the disease?
- No differences in antibody responses were found between blood samples from 92 ME/CFS patients and 50 healthy control subjects.
- However, when analysing only patients with a reported infectious onset of disease, antibody responses against two EBV-related antigens were stronger in the patient group; these results need confirmation.
Funding
NS, FW, EML and CS received funding from ME Research UK with the financial support of The Fred and Joan Davies Bequest.
Video
Nuno has also released a short YouTube video explaining more about his background in ME research and the results of his study, and acknowledging the support of ME Research UK and the Fred and Joan Davies Bequest.
Summary
The emergence of long COVID has highlighted the potential long-term consequences of a viral infection, leading to symptoms such as fatigue, muscle pain and brain fog that can last for weeks or months.
These symptoms are shared by people with ME/CFS, many of whom also report a viral trigger for their illness. But which viruses are associated with ME/CFS, and how might this information help in its diagnosis?
One candidate is Epstein-Barr virus (EBV), which belongs to a family of viruses known as human herpesviruses, and has long been suggested as a trigger for ME/CFS. In his recent work funded by ME Research UK, Dr Nuno Sepúlveda from the London School of Hygiene & Tropical Medicine has been taking another look at this important pathogen.
Nearly all of us are infected with EBV at some time in our lives, and in most cases our immune system can fight it off. But the virus is known to cause several diseases (including autoimmune conditions), and people with ME/CFS are often found to have active EBV infections or antibody reactivity against EBV.
In previous experiments – using data from Prof. Carmen Scheibenbogen’s group at Charité Universitätmedizin Berlin – Dr Sepúlveda identified a number of EBV-derived proteins (antigens) that were increased or decreased in ME/CFS patients compared with control subjects.
He has now extended this work by looking specifically for antibody signatures that could serve as biomarkers for ME/CFS, and focussing on patients with an infectious trigger at their disease onset. The research was conducted in collaboration with a number of other researchers, including Prof. Scheibenbogen in Berlin, and Dr Eliana Lacerda at the London School of Hygiene & Tropical Medicine.
The group analysed antibody responses against 3,054 EBV-derived antigens in 92 patients with ME/CFS and in 50 healthy control subjects. Fifty-four of the patients reported an acute infection at the time their disease began.
The first round of analyses did not find any antibodies associated with ME/CFS, but this changed when the patients were divided into subgroups based on their disease onset. While there were still no associations among those with a non-infectious or unknown disease trigger, in ME/CFS patients with an infection at disease onset two antibody responses were stronger than seen in healthy controls.
Further analyses showed that these two responses could distinguish this subgroup from controls with a high sensitivity and specificity, and may therefore have potential in the diagnosis of these ME/CFS patients with an infectious trigger, specifically those affected by EBV.
Importantly, the researchers plan to confirm these findings in other cohorts of patients from the UK ME/CFS Biobank. They also suggest that the specific EBV-derived antigens identified may provide some evidence of how the reactivation of EBV plays a role in the development of ME/CFS.
As Cort Johnson pointed out in his 2021 blog post, viruses haven’t gone away in ME/CFS, they’ve just got more interesting.
Abstract
Infections by the Epstein-Barr virus (EBV) are often at the disease onset of patients suffering from Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). However, serological analyses of these infections remain inconclusive when comparing patients with healthy controls (HCs). In particular, it is unclear if certain EBV-derived antigens eliciting antibody responses have a biomarker potential for disease diagnosis. With this purpose, we re-analyzed a previously published microarray data on the IgG antibody responses against 3,054 EBV-related antigens in 92 patients with ME/CFS and 50 HCs. This re-analysis consisted of constructing different regression models for binary outcomes with the ability to classify patients and HCs. In these models, we tested for a possible interaction of different antibodies with age and gender. When analyzing the whole data set, there were no antibody responses that could distinguish patients from healthy controls. A similar finding was obtained when comparing patients with non-infectious or unknown disease trigger with healthy controls. However, when data analysis was restricted to the comparison between HCs and patients with a putative infection at their disease onset, we could identify stronger antibody responses against two candidate antigens (EBNA4_0529 and EBNA6_0070). Using antibody responses to these two antigens together with age and gender, the final classification model had an estimated sensitivity and specificity of 0.833 and 0.720, respectively. This reliable case-control discrimination suggested the use of the antibody levels related to these candidate viral epitopes as biomarkers for disease diagnosis in this subgroup of patients. To confirm this finding, a follow-up study will be conducted in a separate cohort of patients.
