Protective Effects of Circumcision Explored

ORLANDO—Uncircumcised men are at increased risk of HIV infection. A new study presented at the 100th Annual Meeting of the American Urological Association (abstract 111) suggests that this is due to high numbers of HIV target cells in the foreskin. Carlos R. Estrada, MD, of Rush-Presbyterian-St. Luke’s Medical Center, Chicago, and his colleagues evaluated 8 pediatric and 6 adult foreskins with and without a history of HIV-1 infection. Cervical biopsy tissue served as a control.

Using immunohistochemistry and image analysis, the researchers quantified three cells targeted by HIV: T cells (CD4+), macrophages (CD68+), and Langerhan’s cells (CD1a+), as well as the HIV coreceptors CCR5 and CXCR4. The foreskins had high numbers of the three target cell types, compared with the cervical tissue, with higher proportions in the adult foreskins. Cells expressing CCR5 predominated, compared with CXCR4 expression.

The tissue specimens were then exposed to HIV-1. Analysis showed that CD4+ T cells and Langerhan’s cells in the inner mucosal surface of the foreskins were seven times more susceptible to HIV infection than cells in the cervical tissue.

"Increased risk of HIV-1 infection in uncircumcised men is likely caused by the presence in the foreskin of large numbers of HIV-1 target cells, especially T cells and Langerhan’s cells, expressing primarily CCR5," Dr. Estrada said. "Since uncircumcised men are likely at greater biological risk of heterosexual HIV-1 acquisition, male circumcision should be considered as an additional HIV protection strategy."