MUSK and inflammatory bowel disease: On the other hand, there are two subtypes of autoimmune pancreatitis that are considered extraintestinal manifestations of IBD.39Type II, the most prevalent, may share pathomechanisms with anti-AchRAB MG, with overexpression of cellular adhesion molecule Mad-1.39Type I is part of the spectrum of IgG4 diseases, similar to anti-MUSK MG.39In fact, up to 4% of the IBD patients can have increased IgG4 levels.39