IgG4- Related TIN: Masquerading as Malignant Infiltrative Disorder

Abstract

Immunoglobulin G4 Related Disease (IgG4-RD) is an autoimmune disease first described in pancreas. IgG4 RD has been reported in various organs and its renal involvement is known as IgG4-Related Kidney Disease (IgG4-RKD). Here, authors report a case of a 37- year-old male who presented with chronic kidney disease. He had generalized lymphadenopathy and hepatomegaly. Investigations revealed proteinuria, raised serum creatinine and high serum protein with marked hypergammaglobulinemia. Radiology revealed bilateral nephromegaly. Renal biopsy was done to rule the infiltrative disorder. Histopathological examination showed extensive periglomerular fibrosis, tubular atrophy and plasma cell-rich inflammatory infiltrate. Foci of storiform fibrosis were also seen. Serum IgG4 levels were found to be 49.3 g/L (reference range 0.03 to 2 g/L). Hence, a diagnosis of IgG4-TIN (Tubulointerstitialnephritis) was rendered. In a background of multiple organ involvement with characteristic histomorphological features a possibility of IgG4 RKD must always be considered.

Keywords

• kidney disease
• malignancy
• pancreas