Protective immunity associated with a strong serological response to a Cryptosporidium-specific antigen group, in HIV-infected individuals.

This study assessed whether serological responses to Cryptosporidium antigens are associated with a reduced risk of diarrheal illness in cases of infection with human immunodeficiency virus (HIV). The association between serological responses to the Cryptosporidium 15/17-kDa and 27-kDa antigen groups and reported diarrheal illness was examined by use of data from a previously published study of cases of HIV infection. In immunosuppressed individuals, a strong serological response to the 27-kDa antigen group was associated with a reduced risk of diarrhea without weight loss. This finding suggests that acquired protective immunity to cryptosporidiosis may be important in controlling the burden of cryptosporidiosis in immunosuppressed individuals.