Similar rate of disease progression among individuals infected with HIV-1 genetic subtypes A-D

Objective: HIV-1 is characterized by a high degree of genetic variation and can be divided into at least 10 distinct genetic subtypes. The purpose of this study was to investigate whether the rate of disease progression shows subtype-specific differences. Design: The investigation was divided into two parts; one study in which 49 ethnic Africans were compared with 49 ethnic Swedes irrespective of the su btype of the infecting virus, and a second study in which 126 individuals i nfected with different genetic subtypes (28 with subtype A, 59 with subtype B, 21 with subtype C and 18 with subtype D) were compared. Methods: CD4 cell counts, the rate of CD4 cell decline, plasma HIV-1 RNA le vels, clinical status and antiviral treatment were prospectively and retros pectively recorded. The HIV-1 subtype had previously been determined by dir ect sequencing of the V3 domain of the env gene. Results: There were no significant differences in the rate of CD4 cell decl ine or clinical disease progression between Africans and Swedes over an obs ervation period of 2 years. Similarly, there were no differences in the rat e of CD4 cell decline, clinical progression or plasma HIV-1 RNA levels betw een individuals infected with subtypes A, B, C or D over a mean observation period of 44 months. Conclusion: Neither the genetic subtype of the virus nor the ethnicity of t he host appear to be major determinants of disease progression. (C) 1999 Li ppincott Williams & Wilkins.