Summary
Thrombopoietin‐receptor agonists (Tpo‐RAs) are highly effective in immune thrombocytopenia (ITP). Recently, cases of durable remission after Tpo‐RA discontinuation in adult ITP have been ...reported. We aimed to describe the subset of patients in whom transient Tpo‐RA therapy may induce a durable response. We studied all adults with primary ITP treated with at least one Tpo‐RA over a 5‐year period (n = 54) and seen at one of three participating referral centres in France. Tpo‐RAs were discontinued in 20 of 28 patients who achieved a complete response. We excluded six patients because a previous treatment at the start of Tpo‐RA treatment may have interfered with the response. Overall, eight patients with chronic ITP showed a sustained response median follow‐up: 13·5 months (range 5–27 months). We could not identify a predictive factor of sustained response. In conclusion, a substantial proportion of ITP patients receiving Tpo‐RAs can maintain a durable response after treatment discontinuation.
Abstract Introduction B-cell depletion with rituximab (RTX) is widely used to treat autoimmune diseases, especially as second-line therapy for immune thrombocytopenia (ITP). The incidence of ...RTX-induced hypogammaglobulinemia is unknown because of heterogeneous follow-up and confounding factors such as concomitant immunosuppressive treatments in most patients. We describe 3 cases and attempted to determine the incidence of RTX-induced hypogammaglobulinemia by a systematic review of the literature. Methods We retrospectively analyzed 189 ITP patients receiving RTX in 3 referral centers in France and conducted a systematic review of 32 studies (results published 2001–2014) reporting the use of RTX for ITP, particularly searching for symptomatic secondary hypogammaglobulinemia. We also searched for case reports of hypogammaglobulinemia after RTX initiation for ITP. Results Of the 189 patients, 3 showed symptomatic hypogammaglobulinemia more than 2 years after RTX infusion (initial immunoglobulin level was normal). All 3 presented recurrent severe infections. In 2, the outcome suggested common variable immunodeficiency. In patient 3, the peripheral blood lacked CD19+ CD20+ B cells and the bone-marrow B-cell precursor level was impaired. Among 1245 ITP patients in the literature who received RTX for ITP, gammaglobulin level was monitored before and after RTX initiation for 351 (28%). For 192 (55%), dosages were available and we identified 21 patients with secondary hypogammaglobulinemia, usually not symptomatic, 14 of whom had received concomitant dexamethasone. Finally, we found 4 case reports of ITP and symptomatic hypogammaglobulinemia possibly related to RTX according to the authors. Conclusions This large analysis led us to recommend monitoring serum immunoglobulin level before and repeatedly after RTX initiation for ITP. Physicians should be aware of hypogammaglobulinemia as a rare but severe complication of RTX.