Analysis of T cell activation pathways in patients with liver cirrhosis, impaired delayed hypersensitivity and other T cell‐dependent functions
Patients with cirrhosis of the liver frequently demonstrate anergy in intracutaneous tests and fail to respond to vaccination, suggesting impaired delayed hypersensitivity and other T cell‐dependent functions in vivo. T cell activation through the coordinated interaction of different cells of the immune system (B cell, antigen‐presenting cells (APC)) is an important step in the induction of cellular and humoral immune responses. Impaired T cell‐dependent functions in patients with liver cirrhosis may thus be explained by defective T cell activation. We prospectively investigated T cell activation pathways in 12 patients (nine males, three females) with alcoholic liver cirrhosis (seven Child Pugh stage A and B (CP A+B), five Child Pugh stage C (CP C)) and five healthy controls and compared the in vitro results of T cell activation with data obtained in vivo, e.g. intracutaneous tests and vaccination against hepatitis B surface antigen (HBs‐Ag). Five out of eight patients who completed vaccination against hepatitis B virus infection were non‐responders; one of the three responders had a non‐protective anti‐HBs titre. Moreover, three of five patients with alcoholic liver cirrhosis CP A+B, and two out of three with CP C were anergic in intracutaneous tests to a set of diverse antigens. All parameters of T cell activation were normal, including proliferation mediated by CD2, CD3–T cell receptor (TCR) complex, and CD28; acquisition of responsiveness to exogenous IL‐2 and IL‐4; activation of proteinkinase C (PKC) by phorbol ester and calcium influx by addition of ionomycin. The ability of monocytes to deliver costimulatory signals was preserved in patients with alcoholic cirrhosis. In addition, serum of patients with alcoholic liver disease did not inhibit T cell proliferation. We conclude that, although in patients with alcoholic liver cirrhosis T cell‐dependent functions are impaired in vivo, T cell activation pathways are not responsible for the observed immune defect.