Use of first line antiretroviral therapy from a free ART programme clinic in Pune, India - A preliminary report.

Background & objectives: The treatment outcomes under national antiretroviral therapy (ART) programme are being evaluated in some ART centres in the country. We carried out this study to analyze the impact of first line antiretroviral therapy in HIV infected patients attending a free ART roll out national programme clinic in Pune, India. Methods: Antiretroviral naive HIV infected patients attending the clinic between December 2005 and April 2008 and followed up till March 31, 2011 were included in the analysis. The enrolment and follow up of these patients were done as per the national guidelines. Viral load estimations were done in a subset of patients. Results: One hundred and forty two patients with median CD4 count of 109 cells/μl (IQR: 60-160) were initiated on treatment. The median follow up was 44 months (IQR: 37-53.3 months). Survival analysis showed that the probability of being alive at the end of 5 years was 85 per cent. Overall increase in the median CD4 count was statistically significant (P<0.001). It was significant in patients with >95 per cent adherence (P<0.001). In 14 per cent patients, the absolute CD4 count did not increase by 100 or more cells/μl at the end of 12 months. Viral load estimation in a subset of 68 patients showed undetectable levels in 61 (89.7%) patients after a median duration of 46 months (IQR: 38.3-54.8). Interpretation & conclusions: The first line treatment was effective in patients attending the programme clinic. The adherence level influenced immunological and virological outcomes of patients.

CD4 estimating reagents in dry format are compatible with conventional flow cytometer; FACSCalibur for estimation of absolute CD4 count & percentages.

Background & objectives: Reliable CD4 counts are important for successful implementation of antiretroviral treatment (ART). Availability of dry CD4 reagents can eliminate cold chain requirement reducing shipment and storage cost. An attempt was made in this study to validate the ReaPan and Rea T Count dry reagents developed by ReaMetrix against the original BD Biosciences liquid reagents. Method: Absolute counts and percentages of CD4, CD8 and CD3 + T cells obtained in 100 HIV infected individuals using the test and reference reagents were analyzed for correlation and agreement using Pearson’s correlation and Bland Altman bias analysis . The stability of the reagents and of the stained samples was analyzed at ambient temperature and at 37oC. Results: The absolute CD4 + T cell count and percentages obtained using test and reference reagents showed correlation coefficients ranging from 833 to 981. A mean bias between dry and reference reagents ranged from 0.8 to 26.4. The ReaPan and Rea T Count reagents were stable up to one month at 37oC also. The samples stained with ReaPan reagents were stable at ambient temperature till day 7 whereas the samples stained with Rea T Count reagents were stable at ambient temperature and at 37oC for 10 days. Interpretation & conclusions: The ReaPan dry reagents can be used on existing FACSCalibur machines with additional training on Cell Quest Pro software without incurring any additional equipment cost and this can eliminate the requirement of cold chain during transport and on site storage. The stability of the stained samples has great clinical significance preventing redrawing of the blood samples from the patients.

A review on peripheral blood CD4+ T lymphocyte counts in healthy adult Indians.

The CD4+ T lymphocytes are the crucial cells in the cascade of events in forming immune response to the foreign antigen and hence monitoring the CD4+ T cell counts to understand the extent of immune deficiency is a common practice. CD4+ T cells are also the primary target cells for human immunodeficiency virus (HIV). Hence CD4+ T lymphocyte count is the most important marker of immune dysfunction in HIV disease progression. The estimation of CD4+ T cell counts is used to decide the initiation of anti retroviral therapy (ART), to monitor the efficacy of ART and to start treatment for opportunistic infections (OIs). To develop the threshold levels of CD4+ T cell counts, data from western countries are being used in India. The CD4+ T cell counts are known to be influenced by race and environmental factors. Hence it is important to establish the reference ranges for the CD4+ T cell counts in the target population to understand the immune dysfunction. The information on the lower limits of the CD4+ T cells count is necessary to decide the initiation and monitoring of ART. The published data on the CD4+ T cells count in healthy Indian adult population have been reviewed, analyzed and discussed in this review article. The requirement of establishment of reference ranges in Indian population is discussed.

Safety & immunogenicity of tgAAC09, a recombinant adeno-associated virus type 2 HIV-1 subtype C vaccine in India.

Background & objective: A phase 1 trial of adeno-associated virus based HIV-1 subtype C vaccine (tgAAC09) was conducted at two sites in Germany and Belgium and one site in India. This paper reports the safety and immunogenicity of tgAAC09 in healthy adult Indian volunteers. Methods: Between January 2005 and December 2006, 30 consenting volunteers were enrolled in the placebo controlled double-blind dose-escalation trial [3x109, 3x1010 and 3x1011 DNase resistant particles (DRPs)/ml]. Single injection of the candidate vaccine was administered to ten volunteers randomized in 8:2 ratio in vaccine and placebo arms at each dosage level. Results: The mean age of study volunteers (16 men and 14 women) was 34 yr. Six local reactogenicity events and 14 systemic reactogenicity events like malaise, fever, headache and myalgia were reported, both were dose-dependent. The difference between the adverse events reported by vaccine and placebo recipients (79 and 67%) was not significant. A modest IFN-γ ELISPOT response [248 spot forming units (SFU)/million cells] was detected in one volunteer from high dose group and low response (56 and 75 SFU/million cells) in two volunteers in low and mid-dose groups. A post-vaccination dose-dependent increase was observed in anti AAV2 neutralizing titres. None of the volunteers showed a positive antibody response to HIV-1. Interpretation & conclusions: The trial was a benchmark in phase I clinical evaluation of HIV candidate vaccines in India. The vaccine was generally well tolerated and raised no safety concerns. The vaccine was found to be weakly immunogenic. It is essential to understand the role of pre-existing immunity against vectors and significance of evaluation in a prime-boost strategy.

HIV infection in India: epidemiology, molecular epidemiology and pathogenesis.

The year 1986 saw first case of HIV infection as well as first report of AIDS case in India. Since then the epidemic has spread throughout the country.In the recent years there is evidence of epidemic being stabilized with decrease in new infections reported from some parts of the country. The absolute number of HIV infections in the country is expected to be close to 2.5 million and National AIDS Control Programme, phase III is geared to contain the epidemic. HIV viruses circulating in India predominantly belong to HIV-1 subtype C. However, there have been occasional reports of HIV-1 subtype A and B. Matter of concern is reports of A/C and B/C mosaic viruses that are being reported from different parts of the country. The data on HIV drug resistance from India is rather limited. Most of the studies have shown that the virus strains from drug naive patients do not show significant level of drug resistance mutations. The few immunological studies in Indian patients show that the Indian HIV infected patients show both HIV-specific CTL responses as well as neutralizing antibody response. Mapping of CTL epitopes showed that while Indian patients identify same regions of Gag antigen as recognized by South African subtype C infected patients, some regions are uniquely recognized by Indian patients. There are very few studies on host genetic factors in India in context with HIV infection.However there are evidences reported of association of host genetic factors such as HLA types and haplotypes and HIV disease.

Immunopathogenesis of HIV infection.

Progression of HIV infection is largely dependent on the interaction between the viral factors and host factors. HIV primarily infects the CD4 lymphocytes in the body. It brings about the destruction of CD4 cells through multiple mechanisms including apoptosis. The loss of CD4 cell population ultimately leads to the inability of infected person to deal with opportunistic organisms. Host genetic factors such as HLA polymorphism and HIV co-receptor polymorphism may influence either susceptibility to infection or disease progression. Innate immune mechanisms may play a role in disease progression. However, adaptive immune response is the most critical component of immune system for control of HIV infection. HIV-specific CD4 helper response and HIV-specific CTL responses have clearly emerged as the most important host factors that may decide the rate of disease progression. However, the role of neutralizing antibodies still remains to be understood in context with the disease progression. One of the gray areas is the role of mucosal immune response in HIV infection. However, it is clear that it is not a single component but orchestrated action of different immune mechanisms will decide the outcome of HIV infection. The studies in persons exposed to HIV infection but who are uninfected and the long term non-progressors will be critical for understanding the immunopathogenesis of HIV infection.

Incident HIV infection among men attending STD clinics in Pune, India: pathways to disparity and interventions to enhance equity.

Systematic disparities in rates of HIV incidence by socioeconomic status were assessed among men attending three sexually transmitted disease (STD) clinics in Pune, India, to identify key policy-intervention points to increase health equity. Measures of socioeconomic status included level of education, family income, and occupation. From 1993 to 2000, 2,260 HIV-uninfected men who consented to participate in the study were followed on a quarterly basis. Proportional hazards regression analysis of incident HIV infection identified a statistically significant interaction between level of education and genital ulcer disease. Compared to the lowest-risk men without genital ulcer disease who completed high school, the relative risk (RR) for acquisition of HIV was 7.02 (p < 0.001) for illiterate men with genital ulcer disease, 3.62 (p < 0.001) for men with some education and genital ulcer disease, and 3.02 (p < 0.001) for men who completed high school and had genital ulcer disease. For men with no genital ulcer disease and those with no education RR was 1.09 (p = 0.84), and for men with primary/middle school it was 1.70 (p = 0.03). The study provides evidence that by enhancing access to treatment and interventions that include counselling, education, and provision of condoms for prevention of STDs, especially genital ulcer disease, among disadvantaged men, the disparity in rates of HIV incidence could be lessened considerably. Nevertheless, given the same level of knowledge on AIDS, the same level of risk behaviour, and the same level of biological co-factors, the most disadvantaged men still have higher rates of HIV incidence.