Persistent parvovirus B19 DNAemia in B-cell depletion: Implications for family planning in multiple sclerosis and...

B-cell depletion has transformed the management of multiple sclerosis (MS) and can be a treatment option in other neuroimmunological disorders, such as neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein-associated disease (MOGAD). However, its immunosuppressive effects increase susceptibility to viral and bacterial infections. During a recent parvovirus B19 (B19V) outbreak across Europe, we noted cases of persistent B19V infections in B-cell depleted patients.

To determine the clinical implications of persistent B19V for the management of B-cell-depleted individuals with MS and related neuroimmunological disorders.

In this retrospective observational study, patients with neuroimmunological disorders followed between 2013 and 2023 and during a B19V outbreak in 2024 undergoing B-cell depletion and diagnosed with B19V infection were included. Clinical presentation, laboratory findings and treatment response were reviewed.

We identified three B-cell depleted individuals with confirmed B19V infection (two with relapse-remitting MS (RRMS) on ocrelizumab, one with MOGAD on rituximab), all female and of childbearing age. Two patients presented with symptomatic acute viral infection consistent with Fifth Disease, including neutropenia, anemia, and elevated liver enzymes. The third patient contracted B19V during early pregnancy, presented with mild flu-like symptoms not specific to B19V, however, her fetus developed signs of fetal anemia. Intravenous immunoglobulin treatment led to rapid clinical and laboratory improvement, yet all patients showed persistent B19V DNAemia.

Given the demographic characteristics of people with MS and related disorders, exposure to communicable childhood diseases may represent a relevant risk factor for potentially severe complications, including adverse pregnancy outcomes, during B-cell depletion therapy.