Objective: To investigate the value of serum levels of IgG4 and CA19-9, and autoantibodies in the diagnosis of IgG4-related sclerosing cholangitis (IgG4-SC).
Methods: We detected the serum IgG4 and CA19-9 of 45 IgG4-SC patients, 173 non-IgG4-SC patients and 48 healthy controls by immunoassay and chemiluminescence, respectively, with antinuclear antibody (ANA), anti-neutrophil antibody (ANCA), anti-smooth muscle antibody (SMA) and anti-mitochondrial antibody (AMA) level detected by indirect immunofluorescence. Then analyze the detection results.
Results: (1) The positive rates of ANA, ANCA, SMA and AMA in patients with IgG4-SC were 40%, 6.67%, 0 and 2.22%. Among them, the positive rate of ANA was significantly higher than that of the healthy control group (p < .01), and the positive rate of ANA, ANCA, SMA and AMA were significantly different from that of the non-IgG4-SC group (p < .05). (2) Serum levels of IgG4 and CA19-9 increased significantly in patients with IgG4-SC compared with the healthy controls (p < .01). The areas under the ROC curve (AUC) of IgG4 and CA19-9 were 0.9750 and 0.6498, respectively (p < .05).
Conclusion: The high levels of serum IgG4 and CA19-9, and autoantibodies detections are of great important clinical value in diagnosis and differential diagnosis of IgG4-SC.
Keywords: CA19-9; IgG4; IgG4-related sclerosing cholangitis; autoantibodies; bile duct cancer; pancreatic cancer.