BILIARY IGA SECRETION IN OBSTRUCTIVE-JAUNDICE - THE EFFECTS OF ENDOSCOPIC DRAINAGE

Background: Immunoglobulin A is the predominant immunoglobulin in the bile. Data on the effects of biliary obstruction on IgA secretion are few. Methods: The serum and bile IgA levels in patients with common du ct stones (n = 27) or with malignant obstructive jaundice (n = 20) wer e collected by insertion of nasobiliary catheters. Single samples of c ommon duct bile from patients with gallstones (n = 24) were collected as controls. Bile samples collected were measured for total IgA, secre tory IgA, and free secretory component levels by sandwich enzyme-linke d immunosorbent assays. Results: Bile total IgA, secretory IgA, and fr ee secretory component in the common duct stones group (82.7 +/- 11.4 mu g/ml, 18.4 +/- 1.7 mu g/ml, 0.74 +/- 0.15 mu g/ml) and the malignan t obstructive jaundice group (81.6 +/- 10.7 mu g/ml, 18.2 +/- 2.4 mu g /ml, 0.57 +/- 0.12 mu g/ml) were found to be significantly lower than those of the control gallstone patients (104.8 +/- 3.4 mu g/ml, 33.2 /- 2.9 mu g/ml, 1.03 +/- 0.12 mu g/ml) (P < 0.05). Serum secretory IgA levels in the common duct stones (26.53 +/- 1.75 mu g/ml) and maligna nt obstructive jaundice groups (26.03 +/- 3.48 mu g/ml) were significa ntly higher than the gallstone group (18.45 +/- 4.56 mu g/ml). The bil e-to-serum concentration ratio of total IgA, secretory IgA, and free s ecretory component levels rose significantly within 48 hours after rel ief of obstruction. Conclusions: Biliary obstruction secondary to both calculus or malignancy of the hepatobiliary system causes suppression of bile IgA secretion and elevated serum level of secretory IgA. Bile secretory IgA secretion recovers with endoscopic drainage of the obst ructed system.