Associations between HLA and immune responses in individuals with chronic schistosomiasis japonica.

The association of an HLA specificity with low or high immune responsiveness to Schistosoma japonicum antigen (Sj) was demonstrated among individuals who had previously been exposed to S. japonicum infection. The frequency of HLA-Aw24 specificity among low responders in the IgG antibody response determined by the enzyme-linked immunosorbent assay (ELISA) was higher than that among high responders. Significant association between HLA-B7 and high responsiveness was observed in the IgE antibody response. The frequency of HLA-Bw52-Dw12 was also found to increase among individuals with higher levels of total serum IgE. These results suggest that antibody responses to Sj are regulated by an immune response (Ir) gene(s) linked to the major histocompatibility complex (MHC), although a possibility of the presence of non-MHC-linked Ir genes is not excluded. Serum IgE levels may also be controlled by a gene(s) linked to the MHC.