Virology & Mycology
Open Access
ISSN: 2161-0517
ISSN: 2161-0517
Marina N Nosik, S Sevostyanihin, A Sobkin and G A Zaharyan
Mechnikov Research Institute of Vaccines and Sera, Russia
Moscow Tuberculosis Clinic, Russia
Scientific Tracks Abstracts: Virol Mycol
Chemokine co-receptors CCR5 (R5) and CXCR4 (X4) are the main HIV-1 receptors. It is considered that in the early stages of HIV-infection dominate R5-tropic viruses. At late stages of HIV infection in 50% -60% of HIV-infected individuals X4- tropic variants of the virus or viruses with double tropism are detected, which is associated with a faster decrease in the number of CD4+ cells and as a consequence with the progression of the disease and the worst prognosis. Maraviroc (MVC) a CCR5- antagonist- is included in the scheme of antiretroviral therapy (ART) if the patient is infected exclusively with an R5-tropic variant of the virus. It is shown that the inclusion of MVC in the therapy scheme leads to a significant reduction in viral load and an increase in the number of CD4+ cells. However, lately in Russia among the newly diagnosed HIV-infected individuals, 32-43% of patients are diagnosed at the late stages of HIV infection. Such patients have a longer CD4+ cell count recovery and more often they have incomplete immune restoration. Also, it should be noted that co-receptor switch is well studied in HIV-1-positive individuals infected by HIV-1 subtype B. In the territory of Russia at present time dominates HIV-1 subtype A6 (IDU-A) â�?�? 85.6%. Given the importance of cell tropism and its significance for clinical implications the goal of the study was to study co-receptors usage in newly HIV-infected individuals diagnosed at the late stages of HIV-infection. Seventy-two drug-na�?¯ve HIV- individuals with advanced HIV-infection (CD4+ cells â�?¤ 200 cells/�?¼l) were enrolled in the study. The analysis of the V3 loop sequences showed that 66.7% of the patients were infected with R5-tropic virus (FPR- false positive threshold level- â�?¥20%) and 33.3% (FPRâ�?¤20%) with X4-tropic variant. Among the R5-tropic variants, 85.5% were of A6 HIV-1 subtype; 10.9% of CRF02_AG recombinant subtype and 3.6% of subtype B. Among X4-tropic variants subtype B prevailed (75%). Thus 66.7% of drug-na�?¯ve patients diagnosed at the late stages of HIV infection were of R5-tropic variant and 85.5% of R5-tropic viruses were of A6 subtype. This indicates that with disease progression in individuals infected with A6 subtype the switch from R5-tropic variant to X4-tropic variant observed in HIV-1 subtype B does not occur. In view of this, it is advisable to include CCR5-antagonist in the scheme of therapy for newly diagnosed HIV-individuals even at the late stages of the disease.
Marina N Nosik had received her PD at the MP Chumakov Institute of Poliomyelitis and Viral Encephalitis, Russian Academy of Medical Sciences, 1992. In 1996 -1998 she was the Head of WHO Collaborating Centre on Smallpox in Moscow, OG Andzaparidze Research Institute for Viral Preparations, RAMS. She has coordinated and led several national and international projects. She has two Government Awards for the work in the field of biology and health protection. At present time she is the Head of the Laboratory. Her main field of research activities is HIV drug resistance; characterization of HIV isolates circulating in the territory of the Russia and former Soviet republics; TB/HIV-co-infection.
E-mail: mnossik@yandex.ru