Rituximab Induced Rare Cystic Lesion in Lungs in a Nephrotic Child: A Case Report.

Rituximab has been extensively used for managing B-cell lymphomas due to its anti-CD20 monoclonal antibody activity. Over the last decade, its application has been extended to manage frequent relapsing or steroid-dependent nephrotic syndrome. Its use has been comparatively safe, but few cases of adverse effects on the lung have been reported in the adult population. These lung injury presentations are rarely reported in a pediatric group with only four cases in the literature. Below is a rare case of rituximab-induced lung injury in a 9-year-old boy with frequent relapse of nephrotic syndrome, which developed after four days of rituximab infusion. Suspecting infection and sepsis, several antibiotics were started, but with no improvement in respiratory complaints, even antifungal and antituberculosis treatments were initiated. Finally, setting up a casual relation with the time of infusion to the development of complaints, association with rituximab was suspected. The patient responded to steroid therapy with complete resolution of respiratory complaints. To our knowledge, this is the first reported case of rituximab-induced cystic lesion in lungs from India.