A case of IgG4-related tubulointerstitial nephritis with left hydronephrosis after a remission of urinary tract tuberculosis.

IgG4-related systemic disease encompasses multi-organ disorders, including tubulointerstitial nephritis. This disease is accompanied by a high serum IgG4 concentration and IgG4-positive plasma cell infiltration. We herein describe a 63-year-old woman with renal failure and dryness of the eyes and mouth, who had been treated with antituberculosis agents for urinary tract tuberculosis. She had a negative finding for a PCR analysis for Mycobacterium tuberculosis, a positive QuantiFERON-TB test, high serum IgG4 concentrations (2,660 mg/dl), and low serum IgM and IgA concentrations (34 and 82 mg/dl, respectively). Imaging tests revealed swelling in the submandibular glands, pancreas, and right kidney. A renal biopsy showed IgG4-positive plasma cell infiltration in the interstitium and tubular atrophy. This case was diagnosed as IgG4-related systemic disease. Corticosteroid therapy improved renal failure and swelling in the submandibular glands, pancreas, and right kidney. The case suggests that an abnormal reaction to tuberculosis may be associated with a predominance of type-2 helper T-cell immunity, thus resulting in IgG4-related systemic disease.