Nagalingeswaran Kumarasamy

Pretreatment HIV Drug Resistance and HIV-1 Subtype C Are Independently Associated With Virologic Failure: Results From the Multinational PEARLS (ACTG A5175) Clinical Trial

BACKGROUNDnEvaluation of pretreatment HIV genotyping is needed globally to guide treatment programs. We examined the association of pretreatment (baseline) drug resistance and subtype with virologic failure in a multinational, randomized clinical trial that evaluated 3 antiretroviral treatment (ART) regimens and included resource-limited setting sites.nnnMETHODSnPol genotyping was performed in a nested case-cohort study including 270 randomly sampled participants (subcohort), and 218 additional participants failing ART (case group). Failure was defined as confirmed viral load (VL) >1000 copies/mL. Cox proportional hazards models estimated resistance-failure association.nnnRESULTSnIn the representative subcohort (261/270 participants with genotypes; 44% women; median age, 35 years; median CD4 cell count, 151 cells/µL; median VL, 5.0 log10 copies/mL; 58% non-B subtypes), baseline resistance occurred in 4.2%, evenly distributed among treatment arms and subtypes. In the subcohort and case groups combined (466/488 participants with genotypes), used to examine the association between resistance and treatment failure, baseline resistance occurred in 7.1% (9.4% with failure, 4.3% without). Baseline resistance was significantly associated with shorter time to virologic failure (hazard ratio [HR], 2.03; P = .035), and after adjusting for sex, treatment arm, sex-treatment arm interaction, pretreatment CD4 cell count, baseline VL, and subtype, was still independently associated (HR, 2.1; P = .05). Compared with subtype B, subtype C infection was associated with higher failure risk (HR, 1.57; 95% confidence interval [CI], 1.04-2.35), whereas non-B/C subtype infection was associated with longer time to failure (HR, 0.47; 95% CI, .22-.98).nnnCONCLUSIONSnIn this global clinical trial, pretreatment resistance and HIV-1 subtype were independently associated with virologic failure. Pretreatment genotyping should be considered whenever feasible.nnnCLINICAL TRIALS REGISTRATIONnNCT00084136.

Ethnic variation in certain hematological and biochemical reference intervals in a south Indian healthy adult population

BACKGROUNDnWe established the biochemical and hematological reference intervals among a south Indian healthy adult population attending an HIV referral centre in Chennai, southern India.nnnMETHODSnIn a cross sectional study, 213 study subjects (129 male and 84 female) were studied between March and August 2005. All of the parameters were analyzed using standard hematological and biochemical techniques.nnnRESULTSnCertain biochemical (viz. total bilirubin, alanine transaminase, albumin, creatinine, total protein, lipid profile, creatine phosphokinase, uric acid and lactate) and hematological (mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration and lymphocyte levels) parameters presented higher upper limits. In addition, the upper limits of white blood cell count, platelet count, hematocrit, red blood cell count and hemoglobin level were low in comparison to the currently reported ranges.nnnCONCLUSIONnEthnic variation in reference intervals was observed in certain biochemical and hematological analytes in a south Indian adult population.

GB virus infection: a silent anti-HIV panacea within?

The GB virus (GBV)/hepatitis G virus is a member of the Flaviviridae family and belongs to the hepatitis group of viruses transmitted parenterally, common among intravenous drug users. The strong association between GBV and HIV infection suggests that the two viruses may share similar epidemiological and transmission features. GBV infection is widely believed to prolong HIV disease progression as well as decreasing the HIV viral load and increasing the CD4(+) T-cell level. GBV-driven anti-E2 antibodies have been shown to inhibit HIV replication in vitro. Preliminary studies also suggest that GBV infection of peripheral blood mononuclear cells leads to increased production of beta-chemokines, which may explain the in vitro inhibitory effects and warrants further studies. With sufficient knowledge of resistance patterns studied in tropical south India, researchers are now keen to study the competitive interactions between GBV-induced chemokines and HIV ligands to bind CCR5.

Hiv-1 Drug Resistance Among Newly Hiv-1 Infected Individuals Attending Tertiary Referral Center in Chennai, India

CONTEXTnIn the era of free HAART, accessibility and availability of ARV has been dramatically increased in India. However, rates of treatment literacy and adherence appear to be sub-optimal. Therefore, it is essential to monitor the extent of primary drug resistance in such settings.nnnMATERIALS AND METHODSnBetween July and October 2006, 18 anti-retroviral-naοve individuals were identified as recent infected by the BED-Capture enzyme immunoassay in a VCTC clinic in Chennai. Specimens from these individuals were subjected to genotypic drug resistance testing. Phylogenetic trees were generated using MEGA for Windows version 4.0 using neighbor-joining method. The significant differences in polymorphic mutation frequencies between the study specimens and established subtype C-specific polymorphisms were examined using the Chi-square test.nnnRESULTSnAmino acid substitution (K103N and V106MV) at drug resistance positions occurred in two (11%) isolates, conferring high-level resistance to the non-nucleoside reverse-transcriptase inhibitors nevirapine (NVP), efavirenz (EFV), delavirdine (DLV) and notably extensive genetic variations were observed. K122E (94.4%) and K49R/KR (11.1%) polymorphisms identified in this study have not been previously described in established subtype-C specific polymorphisms. The rate of polymorphisms showed marked difference at the locations V60, D121, V35, and D123 (P < 0.0001). All the sequences showed maximum homology with Indian HIV-1 subtype C reference strain C.IN.95IN21068.nnnCONCLUSIONSnThe finding of resistance to NNRTIs is of public health importance. There is an urgent need to establish surveillance for primary drug resistance in large scale. Further studies are required to determine the phenotype impact of newer polymorphic mutations in relation to drug resistance and viral fitness.

HIV-1 reverse transcriptase nucleotide substitutions in subtype C-infected, drug-naive, and treatment-experienced patients in South India.

In this large cohort of patients infected with HIV-1 subtype C, virologic failure during antiretroviral therapy was associated with high rates of resistance; however, many nucleotide changes were not congruent with previously documented resistance associated mutations. These data may have implications in interpreting genotypic resistance of HIV-1 subtype C during therapy failure.