Kinetics of anti-M2 antibodies after liver transplantation for primary biliary cirrhosis

Background/Aims: Orthotopic liver transplantation is currently considered as tbe treatment of choice for primary biliary cirrhosis in the terminal stage and, as for other autoimmune liver disease, the risk of recurrence of the disease within the graft has been raised. There is, however, some discrepancy about the risk of recurrence based on pathological analysis. In addition, pathological recurrence of primary biliary cirrhosis within the graft is not always associated with a rise in the serological markers of the disease. In order to clarify this situation, we have monitored antimitochondrial antibodies before and after transplantation. Methods: Antimitochondrial antibodies were detected by indirect immunofluorescence (variation in antibody titers) and the antimitochondrial antibodies-2 by western blotting (variation in the number of peptides recognized) in 16 primary biliary cirrhosis patients followed for at least 4 years after transplantation. Results: Antimitochondrial antibody titers had normalized 1 year after transplantation in seven patients, declined in seven others and remained unchanged in two. Over the 4 years of follow up, four patients demonstrated a subsequent increase in antimitochondrial antibody titers. Western blot analysis demonstrated the loss of one or more bands in seven patients during the first operative year after transplantation and in three other patients thereafter; in six patients the western blotting profile remained identical to that obtained before transplantation. The important changes generally occurred during the first year post-transplantation, without significant changes thereafter, except for three patients who demonstrated a secondary reappearance of the initially last band. Disappearance of all bands was never observed. There was no concordance between the normalization of antimitochondrial antibody titers (indirect immunofluorescence) and the reduction in the number of peptides recognized (western blotting). Serum bilirubin and alkaline phosphatase levels had normalized by 1 year after transplantation, and remained normal thereafter. Routine liver biopsies performed on a yearly basis did not disclose any pattern suggestive of primary biliary cirrhosis recurrence. Conclusions: Antimitochondrial antibody titers decreased in primary biliary cirrhosis patients after liver transplantation, although antimitochondrial antibodies-2 never disappeared as assessed by western blotting. In the present study these features were not associated with biochemical or histoclogical evidence of primary biliary cirrhosis recurrence.