HBV and VZV seroprotection loss in MS patients under DMT.

Background: Strategies recommended to decrease the risk of infection associated with the use of multiple sclerosis disease-modifying treatments include screening and immunization against common viral infections such as varicella-zoster (VZV) and hepatitis B (HBV). However, the data concerning the durability of those vaccine responses and the need for re-test is scarce.
Objectives: We aimed to evaluate HBV and VZV seroprotection loss in MS patients under DMT.
Methods: We conducted a cohort study including patients with basal seroprotective titers against HBV/VZV viruses and a subsequent serology performed at least 3 months apart. We evaluated predictors of seroprotection loss through a binary regression.
Results: HBV seroprotection loss occurred in one-fifth of patients in a median interval of 21.3 months. Anti-CD20 treatment (OR 8.559 95%CI 3.467- 21.130, p < 000.1), age at last serology higher or equal to 55 years (OR 7.506, 95% CI 2.473-22.786, p < 0.001) and basal HBsAb titer (OR 0.992, 95%CI 0.987 -0.996, p=0.001) increase the risk of seroprotection loss. VZV seroprotection loss occurred rarely in a median interval of 21.3 months. We could not identify any factor associated with an increased risk of VZV seroprotection loss.
Conclusions: Anti-CD20 drugs are associated with a loss of seroprotection against HBV in a short-interval follow-up.
Competing Interests: Declaration of Competing Interest The authors report no conflicts of interest.
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