KINETICS OF ANTI-M2 ANTIBODIES AFTER LIVER-TRANSPLANTATION FOR PRIMARY BILIARY-CIRRHOSIS

Background/Aims: Orthotopic liver transplantation is currently conside red as tbe treatment of choice for primary biliary cirrhosis in the te rminal stage and, as for other autoimmune liver disease, the risk of r ecurrence of the disease within the graft has been raised. There is, h owever, some discrepancy about the risk of recurrence based on patholo gical analysis. In addition, pathological recurrence of primary biliar y cirrhosis within the graft is not always associated with a rise in t he serological markers of the disease. In order to clarify this situat ion, we have monitored antimitochondrial antibodies before and after t ransplantation. Methods: Antimitochondrial antibodies were detected by indirect immunofluorescence (variation in antibody titers) and the an timitochondrial antibodies-2 by western blotting (variation in the num ber of peptides recognized) in 16 primary biliary cirrhosis patients f ollowed for at least 4 years after transplantation. Results: Antimitoc hondrial antibody titers had normalized 1 year after transplantation i n seven patients, declined in seven others and remained unchanged in t wo. Over the 4 years of follow up, four patients demonstrated a subseq uent increase in antimitochondrial antibody titers. Western blot analy sis demonstrated the loss of one or more bands in seven patients durin g the first operative year after transplantation and in three other pa tients thereafter; in six patients the western blotting profile remain ed identical to that obtained before transplantation. The important ch anges generally occurred during the first year post-transplantation, w ithout significant changes thereafter, except for three patients who d emonstrated a secondary reappearance of the initially last band. Disap pearance of all bands was never observed. There was no concordance bet ween the normalization of antimitochondrial antibody titers (indirect immunofluorescence) and the reduction in the number of peptides recogn ized (western blotting). Serum bilirubin and alkaline phosphatase leve ls had normalized by 1 year after transplantation, and remained normal thereafter. Routine liver biopsies performed on a yearly basis did no t disclose any pattern suggestive of primary biliary cirrhosis recurre nce. Conclusions: Antimitochondrial antibody titers decreased in prima ry biliary cirrhosis patients after liver transplantation, although an timitochondrial 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 re currence.