Early onset neutropenia and thrombocytopenia following rituximab in lupus nephritis

Biologics have emerged as an important modality of treatment in rheumatic diseases and have allowed the rheumatologist to explore varied therapeutic uses of these drugs. Rituximab, a monoclonal antibody against CD20 receptor is an important member of the biologic armamentarium for the treatment of various refractory autoimmune inflammatory rheumatic diseases. The drug is now widely used in systemic lupus erythematosus for several complications which are refractory to conventional therapy. Although relatively safe, the post‐marketing surveillance of rituximab has revealed a few rare but important adverse reactions. Cytopenia including neutropenia following rituximab, has been vastly reported as a late event (>4 weeks), but a few cases of early onset neutropenia (EON) and thrombocytopenia are also found in the literature. We describe a case of a 35‐year‐old woman with refractory lupus nephritis who developed asymptomatic EON and thrombocytopenia following rituximab infusion. The neutropenia responded well to granulocyte colony‐stimulating factor treatment and the platelets spontaneously recovered. This case report is aimed at highlighting the importance of identifying early onset cytopenia following rituximab which may have an important bearing on the final outcome for the patient.