Antiacetylcholine receptor and antinuclear antibodies in myasthenia gravis. Correlation with HLA, sex and Gm.

Sera from 27 subjects with myasthenia gravis (MG) were examined by immunoassay for antibodies to double-stranded DNA (ds-DNA), RNA-nucleoprotein complexes (ENA) and acetylcholine receptor (ACHR). The prevalence of the genetic markers of sex, HLA and Gm were analyzed in relation to various parameters of these autoantibodies. The highest levels of ds-DNA antibodies were associated with HLA B8 as compared to other HLA antigens (p less than 0.05), females as compared with males (p less than 0.05), and females with HLA B8 (p less than 0.05) when both sex and HLA were analyzed concurrently. An association between low titers and HLA B7 (p less than 0.05), with a significant difference between the B8 females and B7 males (p less than 0.05) was also noted. By contrast, no Gm association was noted for antinuclear antibody parameters, but was observed in females between high ACHR antibody titers and the homozygous phenotype (3; 5, 13) (p less than 0.05). This study of MG implicated HLA and sex factors in the production of a broad spectrum of antinuclear antibodies, while the contrasting Gm association noted with ACHR antibody titers was indicative of distinctive immunogenetic influences over autoantibody production in MG.