Epidemiological Study of the Co-receptor Tropism of HIV-1 Subtype A Spread in the Russian Federation Among naïve and ART-experienced Patients Using V3-based Genotyping Tools

This study is a multicenter, single-step; with estimation of the prevalence of R5, X4, and R5X4-tropic HIV variants in a population of HIV-infected Russians naïve to CCR5-antagonists antiretroviral (ARV) therapy. Additional study objectives are to identify dependence of R5- and X4-tropic HIV variants relations from the duration of infection, stage of HIV infection, the values of CD4-lymphocytes; and to compare the prevalence of R5- and X4-tropic HIV variants in cohorts of naïve and ARVT experienced patients. The study consists of single visit of all patients, during which the following procedures will be performed: obtaining of informed consent, initial evaluation of the possibility of including of the patients in the study, stratification of the patient, and if the quota for this cohort has not yet been reached, inclusion of the patient in the study. Also the detailed information will be collected on the date of birth, place of residence (region, city), date of the 1st HIV+ immune blot test, route of infection, estimation year (month) of infection, stage of HIV infection, all the known results of CD4 cell count and viral load measurements, as well as all the known schemes of ARV therapy. Additionally, the study provides a single blood sampling (of 6.4 mL volume) into a test tube in order to study the HIV tropism by sequencing. It is expected that the inclusion in the study will be completed within approximately 3 months, but this period may be extended depending on the actual inclusion of patients in each of the study centers. The Coordination Center of the study is the Central Research Institute for Epidemiology (hereinafter - the Coordination Center). Patient selection will be performed in 13 participating centers:

• The Federal Research and Methodological Center for AIDS, Moscow
• The North-West District AIDS Center, St. Petersburg
• The St. Petersburg City AIDS Center, St. Petersburg
• The Republican Clinical Hospital of Infectious Diseases, St. Petersburg
• The Volga District AIDS Center, Nizhny Novgorod
• The Republic AIDS Center of the Republic of Tatarstan, Kazan
• The Southern District AIDS Center, Rostov-on-Don
• The Ural District AIDS Center, Ekaterinburg
• The Sverdlovsk Oblast AIDS Center, Ekaterinburg
• The Yamalo-Nenets Autonomous District AIDS Center, Noyabrsk
• The Siberian Federal District AIDS Center, Omsk
• The Krasnoyarsk Regional AIDS Center, Krasnoyarsk

The study will include approximately 900 HIV-infected patients of both sexes aged 18 years or older, citizens of Russia. Patient will be selected from the AIDS centers and the Republican Clinical Hospital for Infectious Diseases, which are participants of the study. List of the study participants includes 12 AIDS centers and one Republican Clinical Infectious Diseases Hospital, so the expected number of patients will be 70 people per participant. The minimum number of patients included in the study must be at least 40 people for each participant, but the actual amount will depend on the success of patient recruitment in each of the study centers. Starting from the 4th month of study, a competitive selection of patients will be allowed, which will end as soon as the total number of enrolled patients will reach 900 people. According to the objectives of the study, HIV tropism in patients not received ART with different immune status, and experienced in ART will be analyzed, so the inclusion of patients in the study should take place according to the following quotas:

1. Naïve patients

2. The level of CD4-lymphocytes >500 (optimum is 16 (12-18 patients))

3. The level of CD4-lymphocytes is 350-500 (optimum is 16 (12-18 patients))

4. The level of CD4-lymphocytes <350 (optimum is 16 (12-18 patients))

5. Patients experienced in ARV