OBJECTIVETo investigate HIV-1 co-receptor usage in patients experienced anti-retroviral therapy (ART) in Anhui and Henan province of China.

METHODSA total of 45 HIV-1 infected individuals who have experienced ART and 109 un-experienced ART patients from Anhui and Henan province, which were called as treatment group and treatment-negative group, were selected as study subjects. HIV-1 strains were isolated from peripheral blood mononuclear cells of whole blood from patients. HIV-1 p24 in the culture supernatant was measured using a commercial enzyme-linked immunosorbent assay (ELISA) kit. HIV-1 co-receptor usage was identified using Ghost cell lines expressing CD4 and the chemokine receptor CCR5 or CXCR4.

RESULTSAmong 45 HIV strains from the treatment group, 22 (48.9%) strains used CCR5 as a co-receptor (R5 tropic strain), 21 (46.7%) strains used CXCR4/CCR5 as a co-receptor (X4/R5 duel tropic strain), and 2 (4.4%) used only CXCR4 as a co-receptor (X4 tropic strain). In 109 strains from treatment-negative group, 96 (88.1%) strains used CCR5 as a co-receptor (R5 tropic strain), 13 (11.9%) strains used CCR5/CXCR4 as a co-receptor use (X4/R5 strain). A significant difference was found between two groups in X4 co-receptor usages (χ(2) = 27.30, P < 0.05). Furthermore, after treated with AZT + DDI + NVP, the HIV-1 CXC4/CCR5 utilization was 59.09% (13/22), meanwhile after treated with D4T + DDI + NVP, the HIV-1 CXC4/CCR5 utilization was 43.48% (10/23), which the difference was not statistical significant (χ(2) = 1.10, P = 0.30).

CONCLUSIONHIV-1 CXCR4/CCR5 co-receptor utilization was higher in ART patients than treatment-negative patients.