DIVERGENCE OF HIV-1 QUASI-SPECIES IN AN EPIDEMIOLOGIC CLUSTER

Background: During treatment with blood components prepared from an HI V-infected donation, two recipients became infected in 1985. One recip ient infected her sexual partner. Objective: To evaluate the evolution of the originally-shared HIV-1 quasispecies in different human hosts over lime, sequence data were obtained from serum from the actual dona tion sample of blood, and from plasma samples collected from the four members of the epidemiologic cluster over a period extending from 1986 to 1993. Methods: The V3 hypervariable region of env and the gag p17 gene were analysed. CD4 and CD8 counts, as well as HIV RNA burden data , were collected. Results: One patient died from AIDS during the study . This patient showed a greater degree of diversity in the V3 region, with a higher positive charge over time, than the other individuals. P hylogenetic analysis revealed that the V3 sequences from each of the f our individuals occupied separate branches of a phylogenetic reconstru ction (tree). Two distinct subgroups evolved in the donor, one with GP GR and the other with GSGR/GSGK at the tip of the V3 loop. This latter group was not detected in the other individuals. The sequences in the sexual partner were no more related to those in the infecting transfu sion recipient than to sequences from the other members of the cluster , consistent with sexual transmission having occurred at a time shortl y after the recipient was infected. Conclusion: The shared HIV-1 quasi species in this epidemiologic cluster diverged in an individual-specif ic manner.