Infliximab treatment for Crohn's disease in a patient with IgA nephropathy.

We describe herein a case of IgA nephropathy in a 34-year-old woman with Crohn's disease (CD) treated with infliximab. CD first appeared at the age of 15 years. An elemental diet was started for remission maintenance. Ten years later, the patient suffered from a recto-vaginal fistula and subtotal colectomy with stoma formation was performed. At the age of 33 years, the patient was investigated for painless macroscopic hematuria and proteinuria. Renal biopsy revealed IgA nephropathy. Mizoribine was started but proteinuria persisted. Due to diarrhea she was admitted to our hospital, and scheduled maintenance therapy with infliximab was initiated. After the first infliximab infusion, the patient presented significant clinical improvement in both diarrhea and proteinuria with concomitant decrease of C-reactive protein to normal levels and proteinuria ~1 g/day. This represents the first report of infliximab treatment in a patient with IgA nephropathy associated with CD and clarifies the importance of tumor necrosis factor-alpha (TNFα) in immunity to renal disease. Further studies are needed to draw firm conclusions for the safety of infliximab in patients with IgA nephropathy.