CMV gastric ulcer in a patient with pauci immune crescentic glomerulonephritis on rituximab - a rare combination.

Cytomegalovirus (CMV) infections are asymptomatic in immunocompetent patients but in immunocompromised patients, CMV infections have varying manifestations depending on their location. Patient who are organ transplant recipients, taking immunosuppressive therapy for a long time are at increased risk of CMV infections. CMV-induced gastric ulcer is very rare but many cases have been reported in the literature. No case describing association between CMV-related gastric ulcer and glomerulonephritis has been reported in the literature so far. In this article, we describe a case of pauci immune crescentic glomerulonephritis in a patient who was on rituximab and long-term steroid therapy and found to have CMV-related gastric ulcer. The association of small vessel vasculitis and CMV-related gastrointestinal infection has not been studied in the literature. Pauci immune crescentic glomerulonephritis is a subtype of rapidly progressive glomerulonephritis manifested by continuous loss of renal functions with features of dysmorphic red blood cells and glomerular proteinuria. Treatment of such condition is a genetically engineered chimeric murine/human monoclonal IgG1 kappa antibody directed against the CD20 antigen known as Rituximab. We also discussed the pathogenesis of CMV- induced gastric ulcer after rituximab therapy. This case emphasizes the importance of opportunistic infections in glomerulonephritis patients and raises the awareness that glomerunephritis patients are at increased risk of opportunistic infections as well. Rituximab was considered to be a safer drug but over the years, the incidence if opportunistic infections in patients on rituximab has been increasing.