ABSTRACT
Objectives: To study the association between common AIDS restriction genes and slow disease progression among perinatally-infected children in India. Methods: ART-naïve children were identified and selected host factors including CCR5-Δ32, SDF1-3’A, CCR5-59029G, HLA-B*27, B*57 were studied using allele-specific PCR-RFLP and SSPGo HLA typing kits. Results: Among 165 children, 10 (6%) long-term non-progressors and 8 (5%) slow progressors were identified. For comparison, 12 children with normal progression of HIV were included. The frequencies of CCR5-Δ32 deletion, SDF1-3’A and CCR5-59029G did not differ significantly. HLA-B*27 and B*57 were observed only in long-term non-progressors or slow progressors, who also harbored either SDF1-3’A and/or CCR5-59029G. Conclusions: There is an association between host genetic factors and slow disease progression in this population.
ABSTRACT
Background & objectives: Monitoring of HIV-infected individuals on antiretroviral treatment (ART) ideally requires periodic viral load measurements to ascertain adequate response to treatment. While plasma viral load monitoring is widely available in high-income settings, it is rarely used in resource-limited regions because of high cost and need for sophisticated sample transport. Dried blood spot (DBS) as source specimens for viral load measurement has shown promise as an alternative to plasma specimens and is likely to be a useful tool for Indian settings. The present study was undertaken to investigate the performance of DBS in HIV-1 RNA quantification against the standard plasma viral load assay. Methods: Between April-June 2011, 130 samples were collected from HIV-1-infected (n=125) and non-infected (n=5) individuals in two district clinics in southern India. HIV-1 RNA quantification was performed from DBS and plasma using Abbott m2000rt system after manual RNA extraction. Statistical analysis included correlation, regression and Bland-Altman analysis. Results: The sensitivity of DBS viral load was 97 per cent with viral loads >3.0 log10 copies/ml. Measurable viral load (>3.0 log10 copies/ml) results obtained for the 74 paired plasma-DBS samples showed positive correlation between both the assays (r=0.96). For clinically acceptable viral load threshold values of >5,000 copies/ml, Bland-Altman plots showed acceptable limits of agreement (-0.21 to +0.8 log10 copies/ml). The mean difference was 0.29 log10 copies/ml. The cost of DBS was $2.67 lower compared to conventional plasma viral load measurement in the setting. Interpretation & conclusions: The significant positive correlation with standard plasma-based assay and lower cost of DBS viral load monitoring suggest that DBS sampling can be a feasible and economical means of viral load monitoring in HIV-infected individual in India and in other resource-limited settings globally.