Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Retrovirology cung cấp cho các bạn kiến thức về ngành y đề tài: Frequent CXCR4 tropism of HIV-1 subtype A and CRF02_AG during late-stage disease - indication of an evolving epidemic in West Africa. | Esbjornsson et al. Retrovirology 2010 7 23 http content 7 1 23 RETROVIROLOGY RESEARCH Open Access Frequent CXCR4 tropism of HIV-1 subtype A and CRF02_AG during late-stage disease - indication of an evolving epidemic in West Africa 1 2 1 3 5 Joakim Esbjornsson Fredrik Mansson Wilma Martinez-Arias Elzbieta Vincic Antonio J Biague Zacarias J da Silva5 Eva Maria Fenyo3 Hans Norrgren4 Patrik Medstrand1 Abstract Background HIV-1 is one of the fastest evolving pathogens and is distinguished by geographic and genetic variants that have been classified into different subtypes and circulating recombinant forms CRFs . Early in infection the primary coreceptor is CCR5 but during disease course CXCR4-using HIV-1 populations may emerge. This has been correlated with accelerated disease progression in HIV-1 subtype B. Basic knowledge of HIV-1 coreceptor tropism is important due to the recent introduction of coreceptor antagonists in antiretroviral therapy and subtype-specific differences regarding how frequently HIV-1 CXCR4-using populations appear in late-stage disease need to be further investigated. To study how frequently CXCR4-using populations appear in late-stage disease among HIV-1 subtype A and CRF02_AG we evaluated the accuracy of a recombinant virus phenotypic assay for these subtypes and used it to determine the HIV-1 coreceptor tropism of plasma samples collected during late-stage disease in Guinea-Bissau. We also performed a genotypic analysis and investigated subtypespecific differences in the appearance of CXCR4 tropism late in disease. Results We found that the recombinant virus phenotypic assay accurately predicted HIV-1 coreceptor tropism of subtype A and CRF02_AG. Over the study period 1997-2007 we found an increasing and generally high frequency of CXCR4 tropism 86 in CRF02_AG. By sequence analysis of the V3 region of our samples we developed a novel genotypic rule for predicting CXCR4 tropism in CRF02_AG based on the combined criteria .
