High prevalence of CXCR4 usage among treatment-naive CRF01_AE and CRF51_01B-infected HIV-1 subjects in Singapore

作者：Ng Kah Ying; Chew Kuan Kiat; Kaur Palvinder; Kwan Joe Yap; Khong Wei Xin; Lin Li; Chua Arlene; Tan Mei Ting; Quinn Thomas C; Laeyendecker Oliver; Leo Yee Sin; Ng Oon Tek^*

来源：BMC Infectious Diseases, 2013, 13(1): 90.

DOI：10.1186/1471-2334-13-90

• CXCR4 usage
• HIV-1
• treatment-naive

Background: Recent studies suggest HIV-1 inter-subtype differences in co-receptor usage. We examined the correlation between HIV-1 subtype and co-receptor usage among treatment-naive HIV-1 subjects in Singapore. Additionally, we investigated whether the subtype co-receptor association was influenced by stage of infection.
Methods: V3 sequences of HIV-1 envelope protein gp120 were obtained from 110 HIV treatment-naive patients and genotypic co-receptor tropism determination was performed using Geno2pheno. Two false-positive rate (FPR) cut-offs, 10% and 5.75% were selected for tropism testing.
Results: Subtype assignment of viral strains from 110 HIV-infected individuals based on partial sequencing of HIV-1 pol, gp120 and gp41 were as follows: 27 subtype B, 64 CRF01_AE, 10 CRF51_01B, and 9 other subtypes. At FPR=10%, 10 (100%) CRF51_01B-infected subjects and 26 (40.6%) CRF01_AE-infected subjects had CXCR4-using virus, compared to 7 (25.9%) subtype B subjects and 1 (11.1%) CRF33_01B-infected subject (P < 0.001). At FPR=5.75%, 10 (100%) CRF51_01B-infected subjects and 20 (31.3%) CRF01_AE-infected subjects had CXCR4-using virus, compared to 4 (14.8%) subtype B and 1 (11.1%) CRF33_01B-infected subjects (P < 0.001). Among those with evidence of seroconversion within 2 years prior to study enrolment, 100% of CRF51_01B-infected subjects had CXCR4-using virus, independent of Geno2pheno FPR.
Conclusion: CRF51_01B and CRF01_AE-infected individuals have higher prevalence of CXCR4-usage compared to subtype B infected individuals. Further studies examining these differences could help optimise the use of CCR5-antagonist in populations with these subtypes, and increase our understanding of HIV-1 biology.

• 出版日期2013-2-19