Multiple sclerosis-associated retrovirus in early multiple sclerosis: a six-year follow-up of a Sardinian cohort

Area of Science:

• Neuroimmunology
• Virology
• Retroviruses

Background:

• Human endogenous retroviruses (HERV)-W family includes MS-associated retrovirus (MSRV).
• MSRV is detected in multiple sclerosis (MS) patients.
• Previous preliminary findings suggested MSRV in CSF of early MS patients indicates poor prognosis over three years.

Purpose of the Study:

• To extend the clinical observation of MSRV presence in CSF of early MS patients up to six years.
• To evaluate the association between MSRV presence and long-term disease progression in MS.
• To assess the impact of MSRV on disability accumulation and relapse rates.

Main Methods:

• Nested RT-PCR assays specific for the pol MSRV gene were used to detect MSRV in CSF.
• A cohort of 18 early MS patients (10 MSRV+ and 8 MSRV-) was followed blindly for six years.
• Clinical data including Expanded Disability Status Scale (EDSS) and annual relapse rate were collected and compared between MSRV+ and MSRV- groups.

Main Results:

• After six years, MSRV+ patients showed significantly higher mean EDSS scores (4.3 vs. 2.2) and annual relapse rates (0.5 vs. 0.3) compared to MSRV- patients.
• Two MSRV+ patients progressed to the chronic progressive phase, while none in the MSRV- group did.
• A significantly higher proportion of MSRV+ patients (9/10) received immunomodulatory or immunosuppressive drugs compared to MSRV- patients (2/8).

Conclusions:

• The presence of MSRV virions in CSF at MS onset is associated with significant disability accumulation and increased clinical re-exacerbations over six years.
• MSRV detection in CSF may serve as a prognostic biomarker for MS progression.
• Further research into the pathogenic role of MSRV in MS is warranted.