Background Multiple sclerosis (MS) is a chronic autoimmune disorder affecting the central nervous system (CNS). Reactivation of Human herpesvirus 6 (HHV-6) and Epstein-Barr virus (EBV) is observed in MS.

Objectives This study investigates immunoglobulins (Ig)G, IgM, and IgA directed against EBV nuclear antigen EBNA-366-406, HHV-6 and EBV deoxyuridine-triphosphatase (dUTPase), and different immune profiles in 58 patients with relapsing remitting MS (RRMS) compared to 60 healthy controls.

Methods We employed enzyme-linked immunosorbent assays (ELISA) to measure the immunoglobulins to viral antigens. Multiplex immunoassays were used to measure cytokines, chemokines and growth factor levels that were used to compute immune profiles, including M1 macrophage, T helper (Th)-1, Th-17, and overall immune activation. We assessed disabilities using the Expanded Disability Status Scale (EDSS) and disease progression using the Multiple Sclerosis Severity Score (MSSS).

Results IgG/IgA/IgM directed to the three viral antigens were significantly higher in RRMS than in controls. RRMS was significantly discriminated from controls by using IgG and IgM against HHV-6 dUTPase, yielding an accuracy of 91.5% (sensitivity=87.3% and specificity=95.2%). Neural network analysis showed that using IgG to EBV-dUTPase, IgM to EBV-dUTPase, and immune profiles yielded an area under the ROC curve of 1 and a predictive accuracy of 97.1%. There were strong associations between IgG/IgM responses to HHV-6 and EBV-dUTPases and the EDSS/MSSS scores and aberrations in M1, Th-17, profiles, and overall immune activation.

Conclusions HHV-6 and EBV reactivation play a key role in RRMS and these effects are mediated by activation of cytokine profiles.

The authors have declared no competing interest.

Funding for the project was provided by the C2F program at Chulalongkorn University in Thailand, grant number 64.310/436/2565 to AFA, the Thailand Science Research, and Innovation Fund at Chulalongkorn University (HEA663000016), and a Sompoch Endowment Fund (Faculty of Medicine) MDCU (RA66/016) to MM. For performance of all antibody assays, funds were provided by Immunosciences Lab., Inc., Los Angeles, CA, USA, and Cyrex Labs, LLC, Phoenix, AZ, USA.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The investigation received approval from the Ethics Committee of the College of Medical Technology at the Islamic University of Najaf, Iraq (Document No. 11/2021). All procedures adhered to both Iraqi and international ethical standards and written informed consent was obtained from all patients and control participants.

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AA managed the blood sample collection and patient-related procedures. AV and AFA conducted the serum biomarker quantification. MM performed the statistical analysis. MM, AV, and EV performed visualization. The initial draft was written by AA and MM, and subsequently revised by AV, YZ, and EV. All authors approved of the last version.