Met-11 of HLA class II DP alpha 1 first domain associated with onchocerciasis.

Human infection with the pathogenic tissue nematode Onchocerca volvulus may result in a spectrum of clinical manifestations or in a putatively immune condition. A methionine at amino acid position 11 of the HLA class II DP alpha 1 chain correlates with the occurring disease after infection (relative risk 3.3). The alternative alanine at position 11 is, conversely, associated with protection from disease ("relative protection' 3.5). DPA1*0301 is associated with the localized form of disease after O. volvulus infection.