We investigated the genetics of Fc receptors, which function as activating receptors on immune cells and help to control HIV through antibody-mediated cellular cytotoxicity. Thus, Fc receptors may be important for virus immunity but might also promote immune hyperactivation that would enhance infection.

We measured abundance of low and high activity alleles in two Fc receptor genes, FCGR2A and FCGR3A, for persons with HIV disease, natural virus suppressors (HIV+, without disease) and healthy controls to show whether genotypes were associated with infection and disease. Individuals homozygous for the high activity allele of FCGR3A (158VV) were predominantly found among HIV progressors and this group was also skewed toward higher allele frequencies for the V158 variant. Both of the HIV positive groups (progressors and natural virus suppressors) had significantly higher frequencies of the V158 allele compared with uninfected controls. There were no apparent associations among FCGR2A alleles and HIV status.

Our results indicate that high activity alleles of FCGR3A may be risk factors for HIV infection or progression and we need to understand how allelic variants affect the balance between virus control and immune activation.