Merkel cell polyomavirus infection in HIV-positive men

To evaluate Merkel cell polyomavirus (MCPyV) DNA prevalence and load among men with human immunodeficiency virus (HIV) (hereafter referred to as HIV-positive men) and among healthy male control subjects.

Prospective study from February 4, 2009, through April 24, 2010.

Dermatology department of a university hospital.

A total of 449 male adults were prospectively recruited, including 210 HIV-positive men who have sex with men and 239 healthy controls. Cutaneous swabs were obtained once from the surface of the forehead in all participants.

Swabs were evaluated for the presence of MCPyV DNA using single-round and nested polymerase chain reaction. The MCPyV DNA load (the number of MCPyV DNA copies per β-globin gene copy) was determined in MCPyV-positive samples using quantitative real-time polymerase chain reaction.

Among 449 forehead swabs analyzed, MCPyV DNA was detected in 242 (53.9%). Compared with healthy controls, HIV-positive men more frequently had MCPyV DNA on nested polymerase chain reaction (49.4% vs 59.0%, P = .046) and on single-round polymerase chain reaction (15.9% vs 28.1%, P = .002). The MCPyV DNA loads in HIV-positive men were similar to those in HIV-negative men, but HIV-positive men with poorly controlled HIV infection had significantly higher MCPyV DNA loads than those who had well-controlled HIV infection (median and mean MCPyV DNA loads, 2.48 and 273.04 vs 0.48 and 11.84; P = .046).

Cutaneous MCPyV prevalence is increased among HIV-positive men who have sex with men. Furthermore, MCPyV DNA loads are significantly higher in HIV-positive men with poorly controlled HIV infection compared with those who have well-controlled HIV infection. This could explain the increased risk of MCPyV-associated Merkel cell carcinoma observed among HIV-positive individuals.