Rituximab-related late-onset neutropenia in patients with rheumatic diseases: Successful re-challenge of the treatment

Objective: Unusual or unexpected effect of treatment Background: We describe here 2 patients who developed late-onset neutropenia after Rituximab treatment. While this phenomenon is well described among patients suffering from hematological malignancies, such adverse effects are rare among patients with rheumatic diseases. Case Report: Two patients, the first with rheumatoid arthritis and the second with granulomatosis with polyangiitis, were treated by Rituximab after all previous treatments failed. The patients developed late-onset neutropenia after several courses of treatment. The first patient, with symptomatic neutropenia, recovered after a single dose of granulocyte macrophage stimulating factor, and the second patient’s neutrophils increased spontaneously. Both patients were retreated by rituximab in their scheduled time without further complications. Conclusions: Our case series is unique because the same phenomenon appeared in patients with different rheumatic diseases. This case series confirms the possibility of continuing the treatment without further adverse effects.