We characterized the cytokine profile in the liver of patients with primary
biliary cirrhosis (PBC). Total RNA was extracted from the biopsy specimens
of 9 patients with early-stage PBC, 10 with chronic hepatitis C (CHC), and
4 normal controls. cDNA was prepared and amplified with a polymerase chain
reaction using primers for interferon (IFN)-gamma and interleukin (IL)-2,
-4, -5, -6, -10, -12 (p40), and -15. Cytokines such as IFN-gamma and IL-5,
-6, -10, -12, and -15 were expressed in most cases of PBC. Expression rates
of IL-5 and IL-6 were higher than in CHC and controls. The higher expressi
on rate of IL-5 in PBC was associated with eosinophil infiltration. IL-2 an
d IL-4 were rarely detected. Semiquantitative analysis revealed that the ex
pression of IFN-gamma and IL-10 was reversed in PBC and CHC: high IFN-gamma
and low IL-10 in PBC and high IL-10 and low IFN-gamma in CHC. These result
s suggest that cytokine expression is skewed in PBC and both Th1 and Th2 cy
tokines may play a role in the pathogenesis.