Primary biliary cirrhosis is associated with specific changes in liver IgG-bearing cell subpopulations

Background/Aims: The density of total IgG-bearing cells and the distribution of their subclasses were studied in the liver of patients with primary biliary cirrhosis. Methods: Immunohistochemistry and computerized image analysis were used to compare liver specimens from 18 patients with primary biliary cirrhosis and 28 with chronic hepatitis of different etiology. Results: The density of total IgG-bearing cells was similar in the two groups. However, in patients with primary biliary cirrhosis the proportion of IgG3-positive cells was significantly higher than in patients with chronic hepatitis (53±7% vs. 7.5±2.4%) (p<10−8). Conversely, IgG1-positive cells were significantly less prevalent in patients with primary biliary cirrhosis than in chronic hepatitis patients (27±6.9% vs. 68±7.2%, p<10−8). Stratification of patients with primary biliary cirrhosis according to histology did not show any difference in the distribution of IgG subclasses associated with the progression of disease. Conclusion: These data suggest a pathogenetic role of local IgG3-bearing cells in primary biliary cirrhosis.