[Changes in the polymorphism and concentrations of components of the class II complement after orthotopic...

The genes of complement factor B, C2 and C4 are located within the major histocompatibility complex class III region on chromosome 6 in man. These components demonstrate a genetic polymorphism which, when determinated, can be used to define complotypes (association of C2, factor B, C4A and C4B allotypes). On the other hand the liver is the main source of the circulating complement component synthesis. The aim of this study was to analyse the kinetics of several complement component (C3, factor B and C4) concentrations in the plasma and to assess changes in the polymorphic pattern of the complotypes after orthotopic liver transplantation. Nephelometry was used for plasma level measurements and factor B, C2 and C4 typings were performed with high voltage electrophoresis or isofocalisation and immunofixation at intervals before, during and after orthotopic liver transplantation in eleven patients.

Complotypes changes were observed 24 hours after liver transplantation in all patients. A slight decrease in C3, C4, and factor B plasma levels was observed in the first hours after transplantation. A rapid increase in the levels of these components was observed subsequently, with normalization in less than 15 days.

These results demonstrate a rapid synthesis of complement components and the changes in complement polymorphic patterns after liver transplantation.