To characterize cases of tubo-ovarian abscesses in women with multiple sclerosis (MS) treated with B-cell depleting therapy (BCT).

Monoclonal antibodies targeting CD20 have become a mainstay of MS treatment but carry established infection risk. Most common infections include respiratory and urinary tract infections, though more severe infections are known to occur. Tubo-ovarian abscesses (TOA) are serious infections seen in women with MS on BCT and often require hospitalization, prolonged antibiotics, and surgical intervention. Clinical characterization and management for these cases is still uncertain.

Retrospective chart review of patients with MS, treated with BCT, at Mass General Brigham, presented as a case series.

Eight women with MS (7 relapsing remitting MS, 1 secondary progressive MS) developed TOAs following BCT. Average age was 40.7 years (24-58) and the average duration of BCT prior to TOA was 3.9 (2.1-5.9) years. All patients were B-cell suppressed (CD19/20 < 0.6). Three of the patients had preceding hypogammaglobulinemia with IgG less then 700 mg/dL (lowest 349 mg/dL). None of the TOAs were associated with sexually transmitted infections (STI). Five cases were associated with an intrauterine device (IUD), requiring removal. All patients fully recovered with antibiotics +/- drainage but three required salpingectomy/salpingo-oophorectomy. Two patients were switched to alternative MS treatment; two patients were maintained on BCT with dose reduction or extended infusion interval; the remaining four patients maintained original regimen. 

BCT in women with MS may be associated with development of TOA in women of childbearing potential without typical association to STI. This has clinical implications on MS treatment and reproductive health.