MARKED GAMMA-DELTA T-CELL DECREASE IN PERIPHERAL-BLOOD OF PATIENTS WITH PRIMARY BILIARY-CIRRHOSIS (PBC)

PBC is a cholestatic liver disease of unknown etiology with autoimmune features that is often associated with other autoimmune diseases. We analyzed peripheral blood T-cell subsets in patients groups with PBC ( n = 11), non-PBC hepatobiliary disease (n = 11) and an age and sex mat ched control group (n = 11) by two color FACS-analysis. Seven out of e leven PBC patients exhibited markedly lowered and nearly undetectable levels of gamma delta T-cells (<0.8%). None of the individuals in the non-PBC hepatobiliary disease (HBD) group or the normal control group had gamma delta values below 1%. The other four individuals in the PBC group had gamma delta values within the normal range. Overall, the PB C group had a statistically significant, lowered mean percentage of ga mma delta T-cells (1.50%) as compared to the hepatobiliary disease gro up (3.76%) and the control group (4.22%, p = 0.01). The percentages of CD4(+) and CD8(+) and alpha beta TCR(+) CD4-CD8(-) double negative ce lls in PBC patients did not differ from the control group. PBC patient s with normal gamma delta cell counts did not differ from the PBC grou p with low gamma delta values in autoantibody titers, liver tests or t reatment of the disease. As a possible cause for the observed decrease of gamma delta T-cells three sera of PBC patients with low gamma delt a T-cell counts were screened by single color, indirect immunofluoresc ence for antibodies to gamma delta T-cell enriched lymphocytes, but no differences to control sera were observed. In conclusion, we describe what appears to be a disease-specific but inexplicable marked decreas e in gamma delta T-cells in the peripheral blood of a group of patient s with PBC. The possible role of a gamma delta-specific superantigen i n the pathogenesis of the disease is discussed.