[Cofactors in the course of HIV infection]

Cohorts of patients infected with the human immunodeficiency virus (HIV), and followed-up since their infection, have identified risk factors of progression to acquired immunodeficiency syndrome (AIDS). The risk of progression increases with the subject's age at contamination by 40% for each decade. Other host factors such as certain HLA subtypes would be related to progression. Virus-related factors have also been described. Sexual or transfusional transmission from a highly immunodepressed subject increases the risk of progression in the infected subject. Progression is more rapid in male homosexuals than in heterosexuals, even after exclusion of Kaposi's syndrome. There has been little success in isolating co-infections which might explain this finding. The more rapid progression in homosexuals could be due to infection with particularly virulent strains or particular subtypes. Finally, progresion is more rapid when signs of primary infection are major or prolonged, an observation which probably results from a complex host-virus interaction. Behavioral factors occurring after contamination (pregnancy, continued intravenous drug abuse, tobacco, alcohol) have not been demonstrated until now to play a role in progression.