A Case of Endothelial Damage-dominant Nephritis Related to IgA Vasculitis after 11 Years' Use of Infliximab for Rheumatoid Arthritis

A 43-year-old Japanese woman with rheumatoid arthritis treated by infliximab and methotrexate for 11 years was admitted for proteinuria and purpura. A kidney biopsy revealed endothelial damage-dominant ne-phritis with IgA deposition. Infliximab and methotrexate were discontinued, and tocilizumab was started; however, proteinuria persisted. Therefore, tocilizumab was discontinued, and oral prednisolone and methyl-prednisolone pulse therapy were administered. After 6 months, urinary protein was less than 0.1 g/day, and purpura subsided. To our knowledge, this is the first case of endothelial damage-dominant nephritis related to IgA vasculitis involving the skin and kidney after long-term use of infliximab and methotrexate.