Involvement of HLA in clinical courses of myasthenia gravis

The relationship between the histocompatibility leukocyte antigen (HLA) phenotypes and the clinical course of myasthenia gravis (MG) was studied in 53 Japanese patients with MG. The frequency of HLA-DRw9 antigen was high in the MG patients who did not need immunosuppressive therapy but only anticholinesterase agents (RR = 4.52; CP less than 0.02), who achieved remission of the disease (RR = 2.98; CP less than 0.05) or who showed a decrease in AChR antibody (Ab) titer (RR = 6.32; CP less than 0.0002), whereas the frequency of HLA-DRw8 antigen was increased in MG patients who underwent immunosuppressive therapy (RR = 4.03; CP less than 0.01), who did not have remission (RR = 4.75; CP less than 0.1) or who showed an increase in AChR Ab titer (RR = 6.48; CP less than 0.01). These data suggest that immunogenetic heterogeneity in MG might be reflected in its clinical course.