Platelet count is associated with plasma HIV type 1 RNA and disease progression.

Thrombocytopenia is a common finding among HIV-1-infected individuals. In addition to their function in hemostasis, platelets have been found to play a role in host immune defenses and to directly interact with HIV-1. To explore the role of platelets in HIV-1 infection, we examined the relationship between platelet number and the natural history of HIV-1 disease in the well-characterized Hemophilia Growth and Development Study cohort. In a multivariate analysis platelets were found to be inversely related to plasma HIV-1 RNA with increasing platelets associated with lower plasma HIV-1 RNA levels (p < 0.001). Despite this, increasing platelet count was independently associated with enhanced risk of progression to AIDS and death (p < 0.001 for both). While there may be multiple explanations for these novel observations, they do generate hypotheses related to the potential influence platelets may have on the natural history of HIV-1 disease.