Association of Km 3 allotype with increased serum levels of autoantibodies against muscle acetylcholine receptor in myasthenia gravis

Abstract

Association of immunoglobulin allotypes with myasthenia gravis was examined in a set of 84 patients presenting autoantibodies against muscle acetylcholine receptor (AChR). Km and G1m(f)/G1m(z) allotypes were determined by PCR-amplification followed by hybridization with allele-specific oligonucleotides. The Km 3 kappa light chain allotype was found to be associated with significantly increased serum levels of anti-AChR autoantibodies in myasthenic patients ( P = 0.014). We hypothesize that an allelic polymorphism of a regulatory (enhancer) sequence closely linked to the Cκ gene segment could account for our finding.