Myriam Delhaye

Atypical presentation of IgG4-related autoimmune pancreatitis - be awake to early detecting subsequent renal involvement: case report and literature review

We report a case of atypical radiological presentation of type 1 autoimmune pancreatitis (AIP) associated with sclerosing cholangitis, corresponding to a recently described systemic disorder named IgG4-related systemic disease (IgG4-RSD). In our patient (a 62 year-old man), magnetic resonance cholangiopancreatography showed atypical stenosis of the main pancreatic duct with upstream dilatation and 2 pseudocysts, unusual in AIP. Pancreatic carcinoma was initially suspected because of a mass on computed tomography and high serum CA19-9 level, but not supported by normal brush cytology of the pancreatic duct. Considering the high serum IgG4 levels and numerous IgG4+ plasma cells in duodenal papillary tissue biopsy, a diagnostic of sclerosing cholangitis and type 1 AIP was retained. Steroid therapy markedly improved clinical, biological and radiological features. Diffusion-weighted magnetic resonance imaging (DW-MRI) DEMONSTRATED cortical nodular lesions in both kidneys. Two years later, biological and radiological relapse was associated with enhanced level of plasma creatinine. As a progressive chronic kidney disease occurred in our case and based on a review of published cases of IgG4-related tubulointerstitial nephritis associated with AIP, we underline the usefulness of DW-MRI for early detection of renal lesions and the importance of biological screening of renal function during the long term follow up of such patients. Correspondence to: Agnieszka AP, Department of Nephrology, Transplantation and Dialysis, Erasme Hospital, Université Libre de Bruxelles,Route de Lennik 808, B-1070 Brussels, Belgium E-mail: agnieszka.pozdzik@chc.be