Infliximab-Associated Xanthogranulomatous Pyelonephritis: A Rare Complication

Abstract

Xanthogranulomatous pyelonephritis (XGP) is one of the rare diseases characterized by chronic inflammation and destruction of the renal parenchyma, and it is usually associated with renal infection, and nephrolithiasis. Infliximab is an anti-tumor necrosis factor-alpha (anti-TNF-α) monoclonal antibody, which is widely used for treating inflammatory bowel disease, and it is known to increase the risk of rare and opportunistic infections. In this study, we report a case of XGP presenting after the initiation of infliximab treatment. We highlight one of the possible complications associated with immunosuppression due to infliximab. Furthermore, the importance of increasing the awareness among physicians for early recognition of this rare complication.

Keywords: anti-tumor necrosis factor blocker; infliximab; ulcerative colitis (uc); xanthogranulomatous pyelonephritis.

Figure 1. Abdominal CT scan without contrast shows horseshoe-shaped kidneys with suspicion of renal mass.

Figure 2. Renal biopsy revealed features of chronic inflammation of the kidney.

The interstitium shows moderate infiltration of mixed inflammatory cells comprised of lymphocytes, plasma cells, many histiocytes, eosinophils, and some neutrophils with focal area of necrosis.

Figure 3. Abdominal CT scan without contrast shows resolution of abscesses.