Improving screening and chemoprophylaxis among child contacts in India's RNTCP: a pilot study

BACKGROUND

While contact screening and chemoprophylaxis is recommended by India's Revised National Tuberculosis Control Programme for asymptomatic children aged <6 years who are household contacts of smear-positive pulmonary tuberculosis (PTB) patients, implementation is suboptimal.

OBJECTIVE

To evaluate the effectiveness of an isoniazid preventive therapy (IPT) register and card in improving the adherence of health care workers (HCWs) to programmatic guidelines.

METHODOLOGY

This prospective study was conducted in two Tuberculosis Units in South India. Child contacts of smear-positive PTB patients initiated on treatment between November 2009 and January 2010 were screened, and IPT was initiated in asymptomatic children. HCWs were trained in the use of the IPT register and card. The process was evaluated using patient and HCW interviews.

RESULTS

Of 87 children identified aged <6 years, 71 (82%) were traced by HCWs; 53 were screened for TB and initiated on IPT, and 39 completed treatment. HCWs expressed satisfaction with the use of the IPT card and register, saying that it helped them to remember to complete required tasks.

CONCLUSION

In a programme setting, with HCW training and introduction of specific documentation (IPT card and register), implementation of contact tracing and chemoprophylaxis for child contacts improved from 19% to 61%.

Inhibition of catalytic activities of botulinum neurotoxin light chains of serotypes A, B and E by acetate, sulfate and calcium

The catalytic domain, known as light chain (Lc), of the most poisonous botulinum neurotoxins (BoNTs), possesses endoprotease activity that triggers the ultimate poisonous effect to animals and humans. X-ray crystallographic structure of Lc of several BoNT serotypes has identified at least four small ligands at or near the respective active sites. They are sulfate ions in LcA, LcB, and LcE; an acetate ion in LcA; a calcium ion in LcB; and a potassium ion in LcD. Roles of these ligands on the structure and function of the proteins are not known. We have investigated the roles of sulfate, acetate, and calcium on the catalytic activities of LcA, LcB, and LcE using 17-35-residue synthetic peptide substrates. All three ligands inhibited all Lc activities. For LcA and LcB, the order of inhibition effectiveness was calcium>sulfate>acetate. The inhibition effectiveness expressed as IC(50), did not correlate with the occurrence or proximity of the ions to the active site. Moreover, addition of acetate or sulfate to LcA did not affect the near-UV circular dichroism spectra, tryptophan, and tyrosine fluorescence spectra, and mid points of thermal denaturation of LcA. Our results suggest that acetate, sulfate, and calcium nonspecifically interact with BoNT Lc, and their occurrence in the crystal structures could have been due to opportunistic binding to complementary pockets.

Oncogenic microRNA 17-92 cluster is regulated by epithelial cell adhesion molecule and could be a potential therapeutic target in retinoblastoma

PURPOSE

Several miRNAs have been reported as candidate oncogenes and tumor suppressors, which are involved in the pathways specifically altered during tumorigenesis or metastasis. The miR 17-92 cluster located in 13q31 locus might contribute to retinoblastoma (RB) oncogenesis as 13q31 is amplified often in RB. We attempted to identify the factors involved in the regulation of miR 17-92 cluster in RB.

METHODS

Real-time quantitative reverse transcriptase PCR was performed to study the expression of the miR 17-92 cluster in primary RB tumors and in Y79 cells after epithelial cell adhesion molecule (EpCAM) silencing. EpCAM was silenced using siRNA and confirmed by western blotting. The Y79 cells were transfected with individual and mixed antagomirs and studied the cell viability by (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, invasion by matrigel analysis and caspase-3 expression by flow cytometry.

RESULTS

The relative expression of miR 17-92 cluster, compared to that of a normal retina, ranged from 25 to 220 fold (p<0.0001), miR-18 being highly expressed in RB. Post EpCAM silencing resulted in a significant decrease (p<0.01) in the expression of the miR 17-92 cluster by 4 to eightfold in Y79 cells. Y79 cells transfected with an antagomirs mix (all 5 miRNAs) showed decreased cell viability (p<0.001) and cell invasion (p<0.001). Similarly, Y79 cells treated with antagomirs mix showed increased expression of caspase-3 (p<0.001), which confirms the anti-proliferative effect of antagomirs.

CONCLUSIONS

This study has showed varied expression of the miR17-92 cluster in primary RB tumors. EpCAM influences miR 17-92 cluster expression in retinoblastoma. In addition, we showed that the miR 17-92 cluster plays a role in RB cell proliferation and invasion. Therefore, targeting the miRNA 17-92 cluster may be beneficial for controlling Y79/RB cell proliferation and invasion.

Global guidelines for treatment of tuberculosis among persons living with HIV: unresolved issues

The Revised National Tuberculosis Control Programme (RNTCP) in India uses a fully intermittent thrice-weekly rifampicin-containing regimen for all tuberculosis (TB) patients, including those who are human immunodeficiency virus (HIV) infected, whereas the World Health Organization (WHO) recommends daily anti-tuberculosis treatment at least during the intensive phase. The WHO recommendation was based on the results of a meta-analysis demonstrating increased risk of recurrence and failure among HIV-infected TB patients receiving intermittent TB treatment compared to a daily regimen. Review of the primary evidence indicates limited, low-quality information on intermittency, mostly from observational studies in the pre-antiretroviral treatment (ART) era. Molecular epidemiology in India indicates that most of the recurrences and many of the failures result from exogenous re-infection, suggesting poor infection control and high transmission rather than poor regimen efficacy. Subsequently published studies have shown acceptable treatment outcomes among HIV-infected TB patients receiving intermittent anti-tuberculosis regimens with concomitant ART. Treatment outcomes among HIV-infected TB patients treated under programmatic conditions show low failure rates but high case fatality; death has been associated with lack of ART. The highest priority is therefore to reduce mortality by linking all HIV-infected TB patients to ART. While urgently seeking to reduce death rates among HIV-infected TB patients, given the poor evidence for change and operational advantages of an intermittent regimen, the RNTCP intends to collect the necessary evidence to inform national policy decisions through randomised clinical trials.

FLT3 and NPM1 mutations in a cohort of AML patients and detection of a novel mutation in tyrosine kinase domain of FLT3 gene from Western India

Acute myeloid leukemia (AML) is an aggressive hematological disorder characterized by the loss of ability of the hematopoietic progenitor cells to differentiate and proliferate normally leading to an accumulation of immature myeloid cells in the bone marrow. Several novel molecular genetic aberrations in FLT3 and NPM1 have been shown to have a prognostic impact in AML, particularly in those having normal karyotype. Though there is substantial amount of data on these mutations from western literature, there is surprisingly little data from Indian subcontinent on the frequency of this mutation in AML patients from India. The present study screens a large cohort of non-acute promyelocytic leukemia (APL) AML patients (207 patients) for the presence of FLT3 and NPM1 mutations and further correlates with cytogenetics, immunophenotypic characteristics and with follow-up data wherever available. During the course of study, 56 APL patients were also studied. Briefly, both FLT3 (internal tandem duplication (ITD) in 19.4% and tyrosine kinase domain (TKD) in 9%) and NPM1 mutations were detected in 28.4% of the total non-APL AML patients screened showing distinct correlations with hematologic, immunophenotypic, cytogenetics characteristics and follow-up. With regards to adult APL patients, 22.2 and 32.6% of the patients showed FLT3 and NPM1 mutation, respectively. In the pediatrics age group (<15 years), 23 and 16% of patients with APL showed FLT3 and NPM1 mutation, respectively, while in non-APL patient is this age group, 23% of patients showed both FLT3 and NPM1 mutation. NPM1 mutation was distinctly uncommon in younger age group of patients. In contrast to report elsewhere, most of our FLT3 mutation was in exon 11 rather than in exon 12. FLT3 mutation due to ITD or TKD mutation was detected in 2:1 ratio in our patients and a new TKD mutation was also detected S840G in an M5 patient who did not go into remission and had a short survival of 3 months from diagnosis. Generally, patients with NPM1 mutation had a very high white cell count but they went into remission more often than those with wild (Wt)-type allele (written as NPM1- and FLT3-, respectively) and FLT3 mutation. These patients also tended to have significantly lower expression of CD34 antigen on flowcytometry. Distinct prognostic subclasses of adult AML patients were identified based on the presence of NPM1 and FLT3 mutations.

Characterization of indoor bioaerosols from a hospital ward in a tropical setting

OBJECTIVES

Study was conducted to assess whether temporal variation exists in airborne microbial concentrations of a hospital ward (west-Chennai, India) using active and passive methods, and characterise the microorganisms.

METHODS

Air samples (duplicates) were collected simultaneously using exposed-plate, impingement (BioSampler) and filtration (personal sampling filter cassette loaded with gelatin filter) methods over different periods of the year. Bacterial plates were incubated at 37°C and observed for growth after 48h; fungal plates were incubated at 25°C and 37°C and observed upto 7 days. Microorganisms were identified using standard microbiological procedures.

RESULTS

Microbial loads were found to vary with the sampling method. Concentrations of bacteria were higher (exposed-plate: 45-150 CFU/plate; impingement: 1.12E+03-1.6856E+05 CFU/m(3); filtration: 3.788E+03-1.91111E+05 CFU/m(3)) than fungi (exposed-plate: 0-13 CFU/plate; impingement: 0-3.547E+03 CFU/m(3); filtration: 0-1.515E+04 CFU/ m(3)). Coagulase-negative Staphylococci and Micrococci were the predominant Gram-positive cocci in active and passive samples. Enterobacter and Pseudomonas were the predominant Gram-negative bacilli. Among fungi, Aspergillus niger was isolated throughout the year. There was no significant temporal variation in airborne microbial loads irrespective of methods.

CONCLUSIONS

Exposed-plate method was found to capture microorganisms efficiently with little variation in duplicate samples, suggesting its use in hospitals for preliminary assessment of indoor air quality and determine pathogenic microorganisms due to particle fall-out.

Clinical impact of the use of 16S rRNA sequencing method for the identification of "difficult-to-identify" bacteria in immunocompromised hosts

Molecular method of 16S rRNA sequencing is reported to be helpful in the accurate identification of organisms with ambiguous phenotypic profiles. We analyzed the use of 16S rRNA sequencing method to identify clinically significant, "difficult-to-identify" bacteria recovered from clinical specimens, and evaluated its role in patient management and consequent clinical outcome. Among the 172 "difficult-to-identify" bacteria recovered over a 4-year period, 140 were gram-positive cocci or gram-negative bacilli; identification by 16S rRNA did not play a role in the management of patients infected with these bacteria. From 32 patients, 33 "difficult-to-identify" gram-positive bacilli were identified; the organisms were mycobacteria, Nocardia, Tsukamurella, Rhodococcus, and Gordonia. In 24 patients for whom clinical data were available, results from the 16S rRNA sequencing method led to treatment change in 14 immunocompromised patients (including 7 hematopoietic stem cell recipients and 1 liver transplant recipient). Therapy was modified in 9 patients, initiated in 3 patients, and discontinued in 2 patients. Most patients' therapy was switched to oral antibiotics with discontinuation of intravascular catheters, facilitating early hospital discharge. All 14 patients were alive 30 days after infection onset. The present study demonstrates the clinical application of 16S rRNA sequencing method to identify "difficult-to-identify" mycobacteria and other gram-positive bacilli in clinical specimens, particularly in immunocompromised hosts.

Alcohol use and HIV sexual risk among MSM in Chennai, India

Men who have sex with men (MSM) in India are a core risk group for HIV. Heavy alcohol consumption is associated with increased sexual risk-taking behaviours in many cultures, in particular among MSM. However, no studies to date have explored alcohol use and HIV risk among MSM in India. MSM in Chennai, India (n = 210) completed an interviewer-administered behavioural and psychosocial assessment. Bivariate and multivariable logistic regression procedures examined behavioural and demographic associations with weekly alcohol consumption. Twenty-eight percent of the sample (n = 58) reported using alcohol at least weekly to the point of being buzzed/intoxicated, which was associated with older age, being married to a woman, being panthi (masculine appearing, predominantly insertive partners) versus kothi (feminine acting/appearing and predominantly receptive partners), weekly tobacco use, unprotected anal sex and unprotected vaginal sex in the three months prior to study enrollment (all P < 0.05). In a multivariable model, unprotected vaginal sex in the previous three months and being married to a women were unique variables associated with weekly alcohol use (all P < 0.01). Further investigation of alcohol use within the context of sexual risk taking is warranted among Indian MSM. Panthis and MSM who are married to women may be particularly likely to benefit from interventions to decrease alcohol intake and concurrent unsafe sex.

Normal bone marrow signal-transduction profiles: a requisite for enhanced detection of signaling dysregulations in AML

Molecular and cytogenetic alterations are involved in virtually every facet of acute myeloid leukemia (AML), including dysregulation of major signal-transduction pathways. The present study examines 5 phosphoproteins (pErk, pAkt, pS6, pStat3, and pStat5) in response to 5 cytokine/growth factors (stem cell factor [SCF], Flt-3/Flk-2 ligand [FL], granulocyte/macrophage-colony stimulating factor [GM-CSF], interleukin-3 [IL-3], and granulocyte-CSF [G-CSF]) within 7 immunophenotypically defined populations, spanning progenitor to mature myeloid/myelomonocytic cells in normal bone marrows with further comparison to AML samples. The normal cohort showed pathway-specific responses related to lineage, maturation, and stimulus. Heterogeneous-signaling responses were seen in homogeneous immunophenotypic subsets emphasizing the additive information of signaling. These profiles provided a critical baseline for detection of dysregulated signaling in AML falling into 4 broad categories, viz lack of response, increased activation, altered constitutive expression, and dysregulated response kinetics, easily identified in 10 of 12 AMLs. These studies clearly show robust and reproducible flow cytometry phosphoprotein analyses capable of detecting abnormal signal-transduction responses in AML potentially contributing to definitive reliable identification of abnormal cells. As functional correlates of underlying genetic abnormalities, signal-transduction abnormalities may provide more stable indicators of abnormal cells than immunophenotyping which frequently changes after therapy and disease recurrence.

Phase Evolution During Crystallization of Amorphous Titanium Aluminide Thin Films: Effect Mn and Nb Additions

Thin films of Ti-aluminides have been sputter deposited using a binary γ-TiAl based target and a quaternary γ-TiAl based target containing alloying additions of Nb and Mn. The as-deposited binary film consisted of microcrystalline agglomerates of α-Ti(Al) embedded in an amorphous matrix whereas the as-deposited quaternary film was found to be amorphous. These films have been annealed in a furnace under a protective Ar atmosphere (referred to as ex situ annealing) as well as on a hot stage in a transmission electron microscope (TEM), referred to as in situ annealing, to study the crystallization behavior of these films and also the effect of Nb and Mn additions on the same. Ex situ annealing of both binary and quaternary films resulted in a nanocrystalline microstructure consisting of primarily γ-TiAl with a small amount of finely dispersed α2-Ti3Al. During in situ annealing of the binary film, at 753 K (stage temperature), growth of the α-Ti(Al) phase was observed together with crystallization of a second phase in relatively thicker regions of the specimen. The first crystalline phase to appear during in situ annealing of the quaternary film was a surface crystallized metastable tetragonal phase at 873 K. Prolonged annealing at the same temperature resulted in the transformation of the amorphous region between grains of the tetragonal phase into γ-TiAl. Formation of the tetragonal and intergranular γ-TiAl phases were also observed in the thin regions of the binary film when it was heated to 873 K.

Genome-wide association study of CSF biomarkers Abeta1-42, t-tau, and p-tau181p in the ADNI cohort

OBJECTIVES

CSF levels of Aβ1-42, t-tau, and p-tau181p are potential early diagnostic markers for probable Alzheimer disease (AD). The influence of genetic variation on these markers has been investigated for candidate genes but not on a genome-wide basis. We report a genome-wide association study (GWAS) of CSF biomarkers (Aβ1-42, t-tau, p-tau181p, p-tau181p/Aβ1-42, and t-tau/Aβ1-42).

METHODS

A total of 374 non-Hispanic Caucasian participants in the Alzheimer's Disease Neuroimaging Initiative cohort with quality-controlled CSF and genotype data were included in this analysis. The main effect of single nucleotide polymorphisms (SNPs) under an additive genetic model was assessed on each of 5 CSF biomarkers. The p values of all SNPs for each CSF biomarker were adjusted for multiple comparisons by the Bonferroni method. We focused on SNPs with corrected p<0.01 (uncorrected p<3.10×10(-8)) and secondarily examined SNPs with uncorrected p values less than 10(-5) to identify potential candidates.

RESULTS

Four SNPs in the regions of the APOE, LOC100129500, TOMM40, and EPC2 genes reached genome-wide significance for associations with one or more CSF biomarkers. SNPs in CCDC134, ABCG2, SREBF2, and NFATC4, although not reaching genome-wide significance, were identified as potential candidates.

CONCLUSIONS

In addition to known candidate genes, APOE, TOMM40, and one hypothetical gene LOC100129500 partially overlapping APOE; one novel gene, EPC2, and several other interesting genes were associated with CSF biomarkers that are related to AD. These findings, especially the new EPC2 results, require replication in independent cohorts.

Nutritional supplementation in HIV-infected individuals in South India: a prospective interventional study

BACKGROUND

Malnutrition in human immunodeficiency virus (HIV)-infected individuals is associated with faster disease progression, higher mortality rates, and suboptimal response to antiretroviral therapy (ART).

METHODS

We conducted a prospective interventional study to evaluate the effects of an oral macronutrient supplement among HIV-infected adults in South India. Patients attending Tuberculosis Research Centre clinics from June 2005 through December 2007 had baseline nutritional assessment and laboratory investigations performed. Patients at 1 center received nutritional counseling and standard care, whereas patients at 2 centers additionally received a macronutrient providing 400 cal and 15 g of protein daily. Study outcomes were changes in anthropometry, body composition, blood chemistry, and immune status at 6 months.

RESULTS

In total, 636 ART-naive patients were enrolled in the study; 361 completed 6 months of follow-up (282 received supplements and 79 received standard care). Mean age +/- standard deviation (SD) was 31 +/- 7 years, mean weight +/- SD was 50 +/- 10 kg, and 42% were male. Significant increases in body weight, body mass index, midarm circumference, fat-free mass, and body cell mass were observed in the supplement group but not in the control group at 6 months; gains were greater in patients with CD4 cell counts <200 cells/microL. No changes were observed in lipid levels, whereas the CD4 cell count decreased in the control group. However, after adjusting for baseline differences, these changes were not statistically significantly different between the groups.

CONCLUSIONS

Macronutrient supplementation did not result in significantly increased weight gain compared with standard care (including nutritional counseling) among patients with moderately advanced HIV disease. The effect of supplementation on specific subsets of patients and on preserving immune function needs further research.

Morphologic and body composition changes are different in men and women on generic combination antiretroviral therapy--an observational study

BACKGROUND

Increasingly effective therapies for HIV infection, combination antiretroviral therapy, are now widely available in developing countries. A range of metabolic complications presenting as abnormalities of body-fat mass distribution in association with dyslipidemia and glucose homeostasis dysregulation, have been recognized as important toxicities in patients treated with these drugs. With increasing use of antiretroviral therapy in India, we examined the association between gender and body shape and composition, one year after initiating combination antiretroviral therapy and attempted to identify simple clinical markers to detect and monitor these changes.

METHODS

Patients on combination antiretroviral therapy (2 NRTIs + 1 NNRTI), attending a HIV clinic between July 2005 and December 2006 had anthropometry clinical examination and bioelectric impedance analysis (BIA) performed along with blood tests at baseline and after 1 year.

RESULTS

Of the 34 patients on combination antiretroviral therapy, 5 males and 12 females had noticeable changes in their body shape. Significant decrease in triceps skin fold thickness, an increase in waist circumference and waist: hip ratio was observed in females. BIA did not show any change in total body fat in either sex.

CONCLUSIONS

Since the presence and severity of fat redistribution could affect adherence as well as the success of antiretroviral therapy, close monitoring is required to detect and prevent this complication early.

Visualizing the molecular interactions of a nucleotide analog, GS-9148, with HIV-1 reverse transcriptase-DNA complex

GS-9148 ([5-(6-amino-purin-9-yl)-4-fluoro-2,5-dihydro-furan-2-yloxymethyl]-phosphonic acid) is a dAMP (2'-deoxyadenosine monophosphate) analog that maintains its antiviral activity against drug-resistant HIV. Crystal structures for HIV-1 reverse transcriptase (RT) bound to double-stranded DNA, ternary complexes with either GS-9148-diphosphate or 2'-deoxyadenosine triphosphate (dATP), and a post-incorporation structure with GS-9148 translocated to the priming site were obtained to gain insight into the mechanism of RT inhibition. The binding of either GS-9148-diphosphate or dATP to the binary RT-DNA complex resulted in the fingers subdomain closing around the incoming substrate. This produced up to a 9 A shift in the tips of the fingers subdomain as it closed toward the palm and thumb subdomains. GS-9148-diphosphate shows a similar binding mode as dATP in the nucleotide-binding site. Residues whose mutations confer resistance to nucleotide/nucleoside RT inhibitors, such as M184, Y115, L74, and K65, show little to no shift in orientation whether GS-9148-diphosphate or dATP is bound. One difference observed in binding is the position of the central ring. The dihydrofuran ring of GS-9148-diphosphate interacts with the aromatic side chain of Y115 more than does the ribose ring of dATP, possibly picking up a favorable pi-pi interaction. The ability of GS-9148-diphosphate to mimic the active-site contacts of dATP may explain its effective inhibition of RT and maintained activity against resistance mutations. Interestingly, the 2'-fluoro moiety of GS-9148-diphosphate was found in close proximity to the Q151 side chain, potentially explaining the observed moderately reduced susceptibly to GS-9148 conferred by Q151M mutation.

Contact screening and chemoprophylaxis in India's Revised Tuberculosis Control Programme: a situational analysis

BACKGROUND

India's Revised National Tuberculosis Control Programme (RNTCP) recommends screening of all household contacts of smear-positive pulmonary tuberculosis (PTB) cases for tuberculosis (TB) disease, and 6-month isoniazid preventive therapy (IPT) for asymptomatic children aged <6 years.

OBJECTIVE

To assess the implementation of child contact screening and IPT administration under the RNTCP.

METHODS

A cross-sectional study conducted in four randomly selected TB units (TUs), two in an urban (Chennai City) and two in a rural (Vellore District) area of Tamil Nadu, South India, from July to September 2008. The study involved the perusal of TB treatment cards of source cases (new or retreatment smear-positive PTB patients started on treatment), interview of source cases and focus group discussions (FGDs) among health care workers.

RESULTS

Interviews of 253 PTB patients revealed that of 220 contacts aged <14 years, only 31 (14%) had been screened for TB, and that of 84 household children aged <6 years, only 16 (19%) had been initiated on IPT. The treatment cards of source cases lacked documentation of contact details. FGDs revealed greater TB awareness among urban health care workers, but a lack of detailed knowledge about procedures.

CONCLUSION

Provision for documentation using a separate IPT card and focused training may help improve the implementation of contact screening and IPT.

Short communication: association of HLA-A*1101 with resistance and B*4006 with susceptibility to HIV and HIV-TB: an in silico analysis of promiscuous T cell epitopes

We have shown the association of HLA-A*11 with resistance and HLA-B*40 and -DR2 with susceptibility to HIV and HIV-TB. In the present study, we performed high-resolution subtyping of HLA-A*11 and -B*40 to identify the subtype level association, using the polymerase chain reaction-based sequence-specific oligonucleotide probe method. Underrepresentation of HLA-A*1101 was observed in overall HIV [p(c) = 0.012, OR 0.42 (95% confidence interval (CI) 0.24-0.72)] and HIV(+)TB(+) [p(c) = 0.001, OR 0.18 (95% CI 0.06-0.46)] compared to healthy controls. Significantly higher frequencies of HLA-B*4006 were observed in overall HIV [p = 0.0001, p(c) = 0.004, OR 2.71 (95% CI 1.58-4.75)], HIV(+)TB(-) [p = 0.0003, p(c) = 0.008, OR 2.82 (95% CI 1.56-5.17)], and HIV(+)TB(+) [p = 0.003, p(c) = 0.086, OR 2.56 (95% CI 1.33-4.95)] compared to healthy controls. An in silico analysis of potential T cell epitopes of consensus Gag and Pol sequences of HIV-1 subtype C Indian strains revealed relatively higher number of promiscuous HLA-B40, HLA-DRB1*1501, and -DRB1*1502 (HLA-DR2)-restricted epitopes in contrast to limited numbers of promiscuous binders restricted by HLA-A*1101. The results suggest that HLA-A*1101 may be associated with protection against HIV and the development of TB in HIV patients while HLA-B*4006 may be associated with susceptibility to HIV and TB development in HIV patients. The present study also suggests that the extent of promiscuity of T cell epitopes of HIV-1 subtype C restricted by HLA alleles exerting opposing effects might differ.

CCR2, MCP-1, SDF-1a & DC-SIGN gene polymorphisms in HIV-1 infected patients with & without tuberculosis

BACKGROUND & OBJECTIVES

Variability in the clinical outcome of persons exposed to and infected with HIV-1 and tuberculosis (TB) is determined by multiple factors including host genetic variations. The aim of the present study was to find out whether chemokine, chemokine receptor and DC-SIGN gene polymorphisms were associated with susceptibility or resistance to HIV and HIV-TB in south India.

METHODS

CCR2 V64I (G/A), monocyte chemoattractant protein-1 (MCP-1) -2518 A/G, stromal cell derived factor-1alpha; (SDF-1alpha) 3'UTR G/A and DC-SIGN gene polymorphisms were studied by polymerase chain reaction based methods in HIV-1 infected patients without TB (n=151), with pulmonary TB (PTB) (n=81) and extrapulmonary TB (n=31), 155 PTB patients without HIV and 206 healthy controls.

RESULTS

The genotype frequencies of CCR2 V64I, MCP-1 -2518 and DC-SIGN polymorphisms did not differ significantly between the study groups. A significantly increased frequency of GG genotype of SDF-1alpha polymorphism was observed among HIV+PTB+ patients compared to healthy controls (P=0.009, Pc=0.027).

INTERPRETATION & CONCLUSIONS

Our data suggest that GG genotype of SDF-1alpha 3'UTR polymorphism may be associated with susceptibility to PTB in HIV-1 infected patients. A better understanding of genetic factors that are associated with TB could help target preventive strategies to those HIV patients likely to develop tuberculosis.

Haplotype analysis of HLA-A, -B antigens and -DRB1 alleles in south Indian HIV-1-infected patients with and without pulmonary tuberculosis

We have shown earlier the association of human leucocyte antigen (HLA)-A11 with resistance and HLA-B40 and -DR2 with susceptibility to HIV and HIV-TB. In the present study, we have attempted to find out the HLA-DR2 subtypes and the possible HLA-A/-B/-DRB1 haplotype combinations that are associated with susceptibility or resistance to HIV and HIV with pulmonary tuberculosis (HIV+PTB+). HLA-DR2 subtyping was carried out by polymerase chain reaction-based sequence-specific oligonucleotide probe method. Overrepresentation of HLA-DRB1*1501 in HIV-positive PTB-negative (HIV+PTB-) patients (P = 0.004, P(c) = 0.06) and -DRB1*1502 in HIV-positive PTB-positive (HIV+PTB+) patients (P = 0.019) was observed as compared to healthy controls. Haplotype analysis revealed an increased frequency of HLA-A2-DRB1*1501 haplotype in HIV+PTB- patients (P = 0.008) and HLA-A2-DRB1*1502 among HIV+PTB+ patients (P = 0.01) compared to healthy controls. The haplotypes B40-DRB1*1501 and B40-DRB1*04 were found to be moderately increased in HIV+PTB(-) and HIV+PTB+ patients (P < 0.05). The study suggests that HLA-A2-DRB1*1501 haplotype may be associated with HIV infection while HLA-A2-DRB1*1502 haplotype might be associated with susceptibility to PTB in HIV patients. Moreover, HLA-B40-DRB1*1501 and HLA-B40-DRB1*04 haplotypes may be associated with susceptibility to HIV infection and to PTB in HIV patients.