Serum IgG subtypes features and differential diagnosis of autoimmunepancreatitis patients

Abstract

To investigate clinical value of serum IgG subclass distribution in differential diagnosis of autoimmune pancreatitis. Inpatients were enrolled as follow, autoimmune pancreatitis (AIP, n=28), acute and chronic pancreatitis (ACP, n=112), pancreatic cancer (PC, n=15), cholangiocarcinoma (CC, n=9), retroperitoneal fibrosis (RPF, n=37), together with healthy controls (n=52). IgG subtypes, amylase, lipase, glucose and CA19-9 were tested.For patients with autoimmune pancreatitis and pancreatic cancer, radiographic CT of abdomen and pathological staining were included for comparison. IgG4 subtype distributed in a wide range as 7.6(1.7-13.8) g/L in AIP, 0.4(0.2-0.7) g/L in ACP, 0.7(0.2-0.9) g/L in PC, 0.5(0.4-6.5) g/L in CC and 0.4(0.2-0.7) g/L in control group, the difference was significant (H=40.536, P<0.001). There were no significant differences of IgG1, IgG3 level in AIP, RPC and control group (all P>0.05). While IgG4 level was 7.6(1.7-13.8), 1.3(0.5-2.6), 0.4(0.2-0.7) g/L in AIP, RPC and control group, respectively. The difference was significant (H=36.833, P<0.001). IgG4 level in RPC group was lower than that in AIP group (P<0.05). And it was meaningful in the differential diagnosis. Serum IgG4 subtype plays an important role in differentiation of autoimmune pancreatitis from associated diseases.