IgG4-related tubulointerstitial nephritis

A 73-year-old man with previous cerebral infarction, diabetes mellitus and IgG4-related disease had received rituximab treatment 2 years prior. He reported poor appetite for a week and was found to have grade I pitting oedema on both legs on physical examination. Contrast-enhanced CT revealed multiple low-density lesions in both kidneys (figure 1), dilatation of the common bile duct and intrahepatic ducts, diffuse enlargement of the pancreas and diffuse thickening of the retroperitoneum. Laboratory data showed elevated serum IgG4, hypocomplementemia, negative anti-phospholipase A2 receptor antibody, non-nephrotic range proteinuria without hematuria and markedly elevated creatinine. The renal biopsy demonstrated chronic tubulointerstitial nephritis (TIN) with an IgG4/IgG ratio of 20% (figure 2). After 1 month of high-dose glucocorticoid treatment, the patient’s leg oedema and serum creatinine levels gradually improved. After discharge, low-dose glucocorticoid with mycophenolate mofetil was prescribed. At 6 months post-treatment, C3/4 levels had normalised, but serum creatinine, IgG4...
Source: Annals of the Rheumatic Diseases - Category: Rheumatology Authors: Tags: ARD, Images in rheumatology Source Type: research