Dynamics of Matricellular Protein Levels in Blood Predict Recovery in Patients with Human Immunodeficiency Virus-Tuberculosis Coinfection.

Chronic immune activation in tuberculosis (TB) associated with human immunodeficiency virus (HIV) infection (HIV/TB) modifies their clinical course. We prospectively measured osteopontin (OPN), full-length galectin-9 (FL-Gal9), and total-Gal9 (T-Gal9) levels in 32 patients with HIV/TB coinfection treated with anti-tuberculosis and antiretroviral therapies over 6-18 months to determine the amelioration of inflammatory conditions in response to the therapies. We observed a significant time-dependent decrease in FL-Gal9 in both pulmonary TB (PTB, n = 20) and extrapulmonary TB (EPTB, n = 12) patients. The levels of T-Gal9, OPN, and CRP decreased significantly after treatment in only PTB patients. We calculated the inflammatory score (INS) indicating immunologic recovery based on the decline in OPN, FL-Gal9, T-Gal9, and CRP levels. Baseline levels of T-Gal9 and OPN positively correlated with INS in all TB and only PTB patients, respectively, indicating that their levels predict better recovery. In contrast, FL-Gal9 levels at the second visit negatively correlated with INS in EPTB patients. The decrease rate in OPN levels at the second visit also correlated positively with INS in PTB patients. Women showed a higher INS and lower levels of FL-Gal9 than men. The patients with moderate grade severity on chest X-ray had higher CD4 cell numbers than those with limited grade severity. Monitoring these markers will help to predict and assess the response to therapy as well as to devise strategies to reduce the complications caused by chronic immune activation in patients with HIV/TB coinfection.

CD4 Lymphocyte Enumeration and Hemoglobin Assessment Aid for Priority Decisions: A Multisite Evaluation of the BD FACSPresto™ System.

BACKGROUND: The BD FACSPresto™ system uses capillary and venous blood to measure CD4 absolute counts (CD4), %CD4 in lymphocytes, and hemoglobin (Hb) in approximately 25 minutes. CD4 cell count is used with portable CD4 counters in resource-limited settings to manage HIV/AIDS patients. A method comparison was performed using capillary and venous samples from seven clinical laboratories in five countries. The BD FACSPresto system was assessed for variability between laboratory, instrument/operators, cartridge lots and within-run at four sites. METHODS: Samples were collected under approved voluntary consent. EDTA-anticoagulated venous samples were tested for CD4 and %CD4 T cells using the gold-standard BD FACSCalibur™ system, and for Hb, using the Sysmex® KX-21N™ analyzer. Venous and capillary samples were tested on the BD FACSPresto system. Matched data was analyzed for bias (Deming linear regression and Bland-Altman methods), and for concordance around the clinical decision point. The coefficient of variation was estimated per site, instrument/operator, cartridge-lot and between-runs. RESULTS: For method comparison, 93% of the 720 samples were from HIV-positive and 7% from HIV-negative or normal subjects. CD4 and %CD4 T cells venous and capillary results gave slopes within 0.96-1.05 and R2 ≥0.96; Hb slopes were ≥1.00 and R2 ≥0.89. Variability across sites/operators gave %CV <5.8% for CD4 counts, <1.9% for %CD4 and <3.2% for Hb. The total %CV was <7.7% across instrument/cartridge lot. CONCLUSION: The BD FACSPresto system provides accurate, reliable, precise CD4/%CD4/Hb results compared to gold-standard methods, irrespective of venous or capillary blood sampling. The data showed good agreement between the BD FACSPresto, BD FACSCalibur and Sysmex systems.

QASI: A collaboration for implementation of an independent quality assessment programme in India.

OBJECTIVE: The HIV pandemic remains a significant global health concern. Accurate determination of CD4+ T-cells in patient samples relies on reliable CD4 enumeration. The Quality Assessment and Standardization programme for Immunological measures relevant to HIV/AIDS (QASI) programme of the Public Health Agency of Canada provides clinical laboratories from resource-limited countries with a mechanism to evaluate the quality of CD4 testing and develop the implementation of an independent national External Quality Assessment (EQA) programme. This study describes how QASI helped develop the capacity for managing a sustainable national CD4 EQA programme in India. DESIGN: Supported by the Public Health Agency of Canada and Clinton Foundation HIV/AIDS Initiative, QASI engaged with the National AIDS Control Organization and the Indian National AIDS Research Institute to assist in technology transfer in preparation for the implementation/management of an independent CD4 EQA programme. Technology transfer training was provided to support corrective actions and to improve the quality of CD4 testing. Inter-laboratory variation of EQA surveys between pre- and post-skill development was compared. RESULTS: Prior to training, coefficient of variation values were 14.7% (mid-level CD4 count controls) and 39.0% (low-level). Following training, variation was reduced to 10.3% for mid-level controls and 20.0% for low-level controls. CONCLUSION: This training assisted the National AIDS Control Organization and the Indian National AIDS Research Institute in identifying the information necessary for management of an EQA programme, and developed the foundation for India to provide corrective actions for sites with challenges in achieving reliable results for CD4 enumeration. This led to a demonstrable improvement in CD4 testing quality and illustrates how country-specific training significantly improved CD4 enumeration performance for better clinical management of HIV care in India.

Duplicate analysis method: a cheaper alternative to commercial IQC materials in limited resource settings for monitoring CD4 testing.

BACKGROUND: India has a large number of HIV infected patients being followed up at anti-retroviral therapy (ART) centers. The patients are regularly offered CD4 count estimation for deciding their eligibility for ART initiation as well as for monitoring response to ART, making CD4 count estimation a very critical test. Hence, quality control of CD4 testing is utmost important for ultimate success of ART program. As the commercial controls are very expensive, internal quality control (IQC), at present, is being done by duplicate analysis method using previous day samples in most of the laboratories. Hence the study was undertaken to review performance of duplicate analysis method for monitoring daily IQC. METHODS: Quality control (QC) data from 11 Indian laboratories using duplicate analysis and/or commercial controls for IQC of CD4 testing was collected for reviewing information on QC parameters such as precision, accuracy and trend monitoring. Precision was determined by r(2) values and mean % variation for duplicate analysis and coefficient of variation (% CV) for commercial controls. Accuracy was monitored by rate of QC failures for both the types of control and trend monitoring was done by plotting LJ charts for commercial controls and by plotting daily % variation for duplicate analysis. RESULTS: The laboratories using duplicate analysis for IQC showed good precision with mean % variation ranging from 0.5 to 7.2. There was good match between r(2) values and % CV of the laboratories performing both the types of QC methods. Rates of QC failures were 2.3 for duplicate analysis and 3 per laboratory-year for IMMUNO-TROL controls. Daily trend monitoring showed fluctuation of daily counts around mean in LJ charts and of percent variation around 0% in duplicate analysis method. Commercially available controls showed limitations such as altered specimen quality leading to difficulties in manual gating and issues with the establishment of laboratory range. CONCLUSION: Duplicate analysis can serve as a cheaper alternative to commercially available controls for IQC of CD4 testing especially when supplemented with other QC measures for controlling variations caused by reagent, equipment, staff and environment in addition to the successful participation in External Quality Assurance programme.

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 37 °C. 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 37 °C 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 37° C 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.

Utility of the point of care CD4 analyzer, PIMA, to enumerate CD4 counts in the field settings in India.

BACKGROUND: In resource limited settings non-availability of CD4 count facility at the site could adversely affect the ART roll out programme. Point of care CD4 enumerating equipments can make the CD4 count available at the site of care and improve the patients' management considerably. This study is aimed at determining the utility of a Point of Care PIMA CD4 analyzer (Alere, Germany) in the field settings in India. METHOD: The blood samples were collected from 1790 participants at 21 ART centers from different parts of the country and tested using PIMA and the reference methods (FACSCalibur, FACSCount and CyFlow SL3). The paired finger prick and venous blood samples from 175 participants were tested by the PIMA CD4 Analyzer and then by FACSCalibur. RESULT: The CD4 counts obtained by PIMA CD4 analyzer showed excellent correlation with the counts obtained by the reference methods; for venous blood the Pearson's r was 0.921, p < 0.001 and the relative bias was 0.2% (range: -42 to 42%) and for finger prick samples, the Pearson's r was 0.856 and the relative bias was -9.1% (range: -46% to 27%). For CD4 ranges; <250, 251-350, 351-500 and >500 cells/mm3, the differences in the median CD4 counts obtained by the reference method and the PIMA analyzer were not significant (P > 0.05) and the relative bias were low (-7 to 5.1%). The Intermachine comparison showed variation within the acceptable limit of%CV of 10%. CONCLUSION: In the field settings, the POC PIMA CD4 analyzer gave CD4 counts comparable to the reference methods for all CD4 ranges. The POC equipment could identify the patients eligible for ART in 91% cases. Adequate training is necessary for finger prick sample collection for optimum results. Decentralization of CD4 testing by making the CD4 counts available at primary health centers, especially in remote areas with minimum or no infrastructure would reduce the missed visits and improve adherence of the patients.

Comparison of capillary based microflurometric assay for CD4+ T cell count estimation with dual platform Flow cytometry.

The CD4+ T cell count estimation is an important monitoring tool for HIV disease progression and efficacy of anti-retroviral treatment (ART). Due to availability of ART at low cost in developing countries, quest for reliable cost effective alternative methods for CD4+ T cell count estimation has gained importance. A simple capillary-based microflurometric assay (EasyCD4 System, Guava Technology) was compared with the conventional flow cytometric assay for estimation of CD4+ T cell counts in 79 HIV infected individuals. CD4+ T cell count estimation by both the assays showed strong correlation (r = 0.938, p < 0.001, 95% CI 0.90 to 0.96). The Bland Altman plot analysis showed that the limits of variation were within agreeable limits of +/- 2SD (-161 to 129 cells/mm3). The Easy CD4 assay showed 100% sensitivity for estimating the CD4+ T cell counts < 200 cells/mm3 and < 350 cells/mm3 and 97% sensitivity to estimate CD4+ T cell count < 500 cells/mm3. The specificity ranged from 82 to 100%. The Kappa factor ranged from 0.735 for the CD4+ T cell counts < 350 cells/mm3 to 0.771 for < 500 cells/mm3 CD4+ T cell counts. The system works with a simple protocol, is easy to maintain and has low running cost. The system is compact and generates minimum amount of waste. Hence the EasyCD4 System could be applied for estimation of CD4+ T cell counts in resource poor settings.

Cytolytic T lymphocytes (CTLs) from HIV-1 subtype C-infected Indian patients recognize CTL epitopes from a conserved immunodominant region of HIV-1 Gag and Nef.

Analysis of the human immunodeficiency virus type 1 (HIV-1) cytolytic T lymphocyte (CTL) epitopes recognized by the targeted population is critical for HIV-1 vaccine design. Peripheral blood mononuclear cells from 47 Indian subjects at different stages of HIV-1 infection were tested for HIV-1 Gag-, Nef-, and Env-specific T cell responses by interferon (IFN)- gamma enzyme-linked immunospot (ELISPOT) assay, using pools of overlapping peptides. The Gag and Nef antigens were targeted by 83% and 36% of responders. Five immunodominant regions, 4 in Gag and 1 in Nef, were identified in the study; these regions are conserved across clades, including the African subtype C clade. Three antigenic regions were also found to be recognized by CTLs of the study participants. These regions were not identified as immunodominant regions in studies performed in Africa, which highlights the importance of differential clustering of responses within HIV-1 subtype C. Twenty-six putative epitopes--15 Gag (10 in p24 and 5 in p17), 10 Nef, and 1 Env (gp 41)--were predicted using a combination of peptide matrix ELISPOT assay and CTL epitope-prediction software. Ninety percent of the predicted epitopes were clustered in the conserved immunodominant regions of the Gag and Nef antigens. Of 26 predicted epitopes, 8 were promiscuous, 3 of which were highly conserved across clades. Three Gag and 4 Nef epitopes were novel. The identification of conserved epitopes will be important in the planning of an HIV-1 vaccine strategy for subtype C-affected regions.

Rapid disease progression in human immunodeficiency virus type 1-infected seroconverters in India.

To determine if the early immunological and virological events of HIV infection are unique in a setting with limited access to health care and HIV-1 subtype C infection, we undertook a prospective cohort study to characterize the early natural history of HIV viral load and CD4(+) T lymphocyte counts in individuals with recent HIV seroconversion in India. CD4(+) T lymphocyte counts were prospectively measured for up to 720 days in 46 antiviral drug-naive persons with very early HIV infection, documented by HIV antibody seroconversion. HIV viral RNA levels were measured subsequently on reposited plasma samples from these same time points. The median viral load "set point" for Indian seroconverters was 28,729 RNA copies/ml. The median CD4(+) cell count following acute primary HIV infection was 644 cells/mm(3). Over the first 2 years since primary infection, the annual rate of increase in HIV viral load was +8274 RNA copies/ml/year and the annual decline in CD4 cell count was -120 cells/year. Although the viral "set point" was similar, the median trajectory of increasing viral load in Indian seroconverters was greater than what has been reported in untreated HIV seroconverters in the United States. These data suggest that the more rapid HIV disease progression described in resource-poor settings may be due to very early virological and host events following primary HIV infection. A rapid increase in viral load within the first 2 years after primary infection may have to be considered when applying treatment guidelines for antiretroviral therapy and opportunistic infection prophylaxis.