CCR5 expression and duration of high risk sexual activity among HIV-seronegative men who have sex with men

Thomas, Susan M.; Tse, David K.; Ketner, D. Scott; Rochford, Gemma; Meyer, Daniel A.; Zade, David D.; Halkitis, Perry N.; Nádas, Arthur; Borkowsky, William; Marmor, Michael

doi:10.1097/01.aids.0000244207.49123.ff

Cited by 21 publications

(14 citation statements)

References 24 publications

(26 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…CCR5 plays a major role in host susceptibility to HIV-1 infection [10], [34], [39]. In Blantyre, Malawi, among mothers with low viral loads, this study found a reduction in the risk of MTCT in babies bearing specific CCR5 variants.…”

Section: Discussionmentioning

confidence: 57%

CCR5 Haplotypes and Mother-to-Child HIV Transmission in Malawi

et al. 2007

View full text Add to dashboard Cite

BackgroundCCR5 and CCR2 gene polymorphisms (SNPs) have been associated with protection against HIV transmission in adults and with delayed progression to AIDS. The CCR5 Δ32 deletion and SNP -2459G are associated with reduced expression of the CCR5 protein.Methodology/Principal FindingsWe investigated the association between infant CCR2/CCR5 diplotype and HIV mother to child transmission (MTCT) in Malawi. Blood samples from infants (n = 552) of HIV positive women who received nevirapine were genotyped using a post-PCR multiplex ligase detection reaction and haplotypes were identified based on 8 CCR2/CCR5 SNPs and the open reading frame 32 base pair deletion. Following verification of Hardy-Weinberg equilibrium, log linear regression was performed to examine the association between mutations and MTCT. Overall, protection against MTCT was weakly associated with two CCR5 SNPs, -2459G (Risk ratio [RR], 0.78; confidence interval [CI], 0.54–1.12), and the linked CCR5 -2135T (RR, 0.78; CI, 0.54–1.13). No child carried the CCR5 Δ32 SNP. Maternal Viral Load (MVL) was found to be an effect measure modifier. Among mothers with low MVL, statistically significant protection against MTCT was observed for -2459G (RR, 0.50; CI, 0.27–0.91), and -2135T (RR, 0.51; CI, 0.28–0.92). Statistically significant protection was not found at high MVL.Conclusions/SignificanceResults from this study suggest that CCR5 SNPs -2459G and -2135T associated with reduced receptor expression protect against MTCT of HIV at low MVLs, whereas high MVLs may over-ride differences in coreceptor availability.

show abstract

Section: Discussionmentioning

confidence: 57%

CCR5 Haplotypes and Mother-to-Child HIV Transmission in Malawi

et al. 2007

View full text Add to dashboard Cite

show abstract

“…The MSM sexual practices are described below according to the risk of exposure to HIV. [174][175][176][177][178][179][180][181] High-risk sexual behaviours ▸ Barebacking ▸ Unprotected anal intercourse (UAI) with an HIVseropositive partner ▸ Rimming (anal/oral sex play) ▸ Fisting (insertion of the hand into the anus) ▸ Use of sex toys and shared drug implements ▸ UAI with casual partners ▸ UAI with partners of an unknown or discordant HIV status ▸ Having multiple sex partners The number of datasets used for each calculation are given in parenthesis. *Considering the median equals mean (primarily the median and in its absence the mean).…”

Section: High-risk Msmmentioning

confidence: 99%

Analysis of duration of risk behaviour for key populations: a literature review

et al. 2012

View full text Add to dashboard Cite

BackgroundThe objective of this paper is to review literature in order to calculate regional estimates of the average duration of time individuals maintain a specific high-risk behaviour.MethodsThe review targeted the key populations of female sex workers (FSW), male clients of female sex workers (MCFSW), people who inject drugs (injecting drug users (IDU)) and high-risk men who have sex with men (MSM). To be included in the review the study had to provide information on (1) the time a person spent at risk until death or cessation of the risk behaviour, (2) the percentage of the sample who initiated the risk behaviour in less than a year or (3) the mean or median duration of the behaviour from a representative sample.Results49 papers were found for the FSW population describing the period of time FSW stay in sex work to be between 2.9 years (Asia) and 12 years (Latin America). Eight papers were found for MCFSW showing the duration of the risk behaviour in this category varying from 4.6 years in Africa to 32 years in Asia. 86 papers were reviewed for the population of IDU showing that the average time a person injects illegal drugs varies from 5.6 years (Africa) to 21 years (South America). No information was found for duration of high-risk behaviour among MSM; instead, the definitions found in the literature for high- and low-risk behaviour among MSM were described.ConclusionsThere is high variability of estimates of duration of high-risk behaviours at regional level. More research is needed to inform models and prevention programmes on the average duration of time individuals maintain a specific high-risk behaviour.

show abstract

“…That a polymorphism at a single amino acid site can have such profound consequences agrees with the first report of species-specific selection in primate lentiviruses, which demonstrate that efficient spread of SIVcpz in human cells depend on a single amino acid change in Gag[53]. Our proposal is indirectly supported by transmission studies in discordant couples with known CCR5 genotype; if the uninfected partner were heterozygous for the Δ32-CCR5 allele, and thus had lower levels of CCR5 on T cells and monocytes[43], HIV transmission decreased during both heterosexual[45] and homosexual[43, 44] contact, although one study found no effect[54]. …”

Section: Discussionmentioning

confidence: 82%