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.