- HCV infection is tied to a 63% lower risk for multiple sclerosis (MS), according to data from a large population study.
Why this matters
- MS etiology is unknown, but increased risk has been demonstrated after infection with the Epstein-Barr virus; in contrast, risk is decreased among people living with HIV.
- Study of 42,522 patients with HCV, matched by age, sex, and location with up to 5 non-HCV individuals (n=202,694), all identified through nationwide Swedish inpatient and outpatient care registers from 2001 to 2013.
- Mean observation time in the HCV and comparator cohorts was 6.59 and 7.42 years, respectively.
- Funding: AbbVie.
- MS incidence was 0.087% (n=37) in the HCV cohort vs 0.27% (n=544) in the comparator cohort.
- HCV patients had a lower risk for MS diagnosis (standardized incidence ratio [SIR], 0.37; 95% CI, 0.26-0.50).
- MS rates were lower in the HCV vs comparator cohort for both men (0.075% vs 0.18%) and women (0.11% vs 0.43%).
- MS risk was lower in both HCV-infected men (SIR, 0.48; 95% CI, 0.30-0.73) and women (SIR, 0.29; 95% CI, 0.16-0.47).
- MS risk remained lower in 4 sensitivity analyses that improved diagnostic stringency.
- No data on treatment, MS risk factors in the HCV cohort.