A Clustering Phenomenon of HCV-1a Strains from HIV-co-infected Patients Could Be Related to the Epidemics of HIV-BF: Buenos Aires, Argentina

FEDERICO BOLCIC; NATALIA LAUFER; LEANDRO JONES; JORGE QUALERI

Conferencia; 19th Conference on Retrovirus and Opportunistic Infections; 2012

Background: The HIV and hepatitis C virus (HCV) share the same transmission routes, which lead to high co-infection rates. Among HIV+ individuals HCV co-infection rates reached 21% in Argentina, the most predominant subtype being HCV-1a. HIV-BF is the most frequent HIV subtype in Argentina and it has been suggested that it emerged in Latin America around 1970. The aim of this work was to infer the phylodynamics and the phylogenetic relatedness among HCV-1a and HIV strains from Argentinean HCV/HIV-co-infected patients. Methods: From Argentinean patients co-infected with HIV, 25 HCV-1a strains were studied based on sequences from the E2 and NS5A genes. Maximum likelihood phylogenetic trees were inferred for E2, NS5A, and E2-NS5A concatenated sequences: 6 HIV isolates could be amplified for pol region and maximum likelihood trees performed. HIV recombinant analysis was performed by jumping profile Hidden Markov Model probabilistic approach. The time of the most recent common ancestor for Argentinean sequences was estimated by the Beast program using the relaxed clock assuming an uncorrelated lognormal prior distribution. Results: Phylogenetic analyses of the HCV-1a sequences indicated that 12 strains were highly related to each other, constituting a highly supported monophyletic group named called the Argentinean Cluster. The remaining HCV strains were interspersed along the phylogenetic trees. Bayesian coalescent analyses for HCV-1a Argentinean Cluster isolates indicated that the time of the most recent common ancestor (tMRCA) was nearly 20 years ago overlapping with the recently estimated age for the HIV-BF epidemics in Argentina. The genomic characterization based on pol gene analysis from HIV viremic patients showed that most of the HIV isolates from patients co-infected with HCV-1a Argentinean Custer were BF recombinants with identical recombination patterns. Conclusions: A new cluster of HCV-1a sequences has emerged in Argentinean HIV co-infected patients. The coincidence observed between the tMRCA of the HCV-1a Argentinean Cluster and the Argentinean HIV-BF epidemics as well as the concordance in the HIV recombination pattern of isolates included in this cluster, supports the hypothesis that a lineage of HCV-1a could have been coincidentally introduced into Argentina with the HIV-BF epidemics.