[Autoimmune pancreatitis with normal IgG4-Levels: 4 case reports and review of the literature]

We report four cases of autoimmune pancreatitis in an 18-, a 22- and a 26-year-old male patient and a 20-year-old female patient. The 20-year-old female patient was admitted to the hospital with upper abdominal pain and jaundice, the 18-year-old patient with recurrent acute pancreatitis and cholestasis, the 26-year-old patient with right upper abdominal pain for four weeks and laboratory findings suggesting an acute pancreatitis. The 22-year-old patient presented with painless jaundice. EUS-guided fine needle aspiration was performed in all patients. The cytological findings and the EUS were decisive for the diagnosis of autoimmune pancreatitis in all four cases. In contrast, no patient showed elevated IgG4, or antibodies for carboanhydrase-II, for lactoferrin, or rheumatoid factor, serum markers reported to be positive in autoimmune pancreatitis. All patients were treated successfully with steroids, one patient relapsed after discontinuing the steroid medication and required renewed therapy. These case reports demonstrate that autoimmune pancreatitis should be considered in the differential diagnosis in cases of pancreatitis and/or jaundice also in western countries. As demonstrated, the diagnosis should not be based solely on the elevation of IgG4 or autoantibodies.