Elevated serum levels of antibodies to carbonic anhydrase I and II in patients with chronic pancreatitis

An immune-mediated reaction to pancreatic structures has been postulated fo r the pathogenesis of chronic pancreatitis (CP). Several reports demonstrat e the presence of antibodies to the pancreatic ductal epithelium in some pa tients suffering from CP. Serum antibodies to carbonic anhydrase I (anti-CA I) and II (anti-CA II) are present in patients affected by idiopathic CP. The aim of this study was to evaluate the presence of anti-CA I and anti-CA II in a series of patients with CP. We studied 78 consecutive CP patients (62 male, 16 female; mean age 48.6 +/- 10.2 years) referred to the Verona U niversity Center for the Study of the Pancreas. As a control group, we stud ied 26 healthy subjects recruited from among the medical and nursing staff of the center. Serum anti-CA I and anti-CA II levels were quantified by enz yme-linked immunosorbent assay using a standard method with minor modificat ions. The mean absorbance of antibodies was higher in CP patients than in c ontrol subjects (anti-CA I: 0.064 +/- 0.042 vs. 0.047 +/- 0.015, p = 0.051; and anti-CA II: 0.038 +/- 0.02 us. 0.029 +/- 0.014, p = 0.033). Positive r esults were arbitrarily defined as absorbance values >0.067 for anti-CA I a nd 0.047 for anti-CA II. We found anti-CA I and anti-CA II positivity in 21 of 78 (27%) and 20 of 78 (26%) of CP patients, respectively, and in only t wo of 26 control subjects (7.7%) (p = 0.032 and 0.039). Twenty-two of 36 su bjects in the control group (84.6%) and 48 of 78 patients (61.5%) in the CP group tested negative For both antibodies (p = 0.03). None of the control subjects and 12 of 78 (16.6%) of the CP patients tested positive for both a nti-CA I and anti-CA II. We observed a significant correlation between anti -CA I and anti-CA II serum levels in control subjects (R = 0.423; p = 0.016 )and in CP patients (R = 0.584; p < 0.0001). No correlation was found betwe en serum antibody levels and any of the following variables: length of dise ase, alcohol consumption, smoking habits, pancreatic surgery, pancreatic ca lcifications, diabetes, and steatorrhea. Serum levels of anti-CA I and anti -CA II are elevated in some patients suffering from CP.