Implementation and assessment of a model to increase HIV testing among men who have sex with men and transgender women in Thailand, 2011-2016.

HIV testing among men who have sex with men (MSM) and transgender (TG) women remains low in Thailand. The HIV prevention program (PREV) to increase HIV testing and link those who tested HIV-positive to care provided trainings to peer educators to conduct target mapping, identify high risk MSM and TG women through outreach education and offer them rapid HIV testing. Trained hospital staff provided HIV testing and counseling with same-day results at hospitals and mobile clinics and referred HIV-positive participants for care and treatment. We used a standardized HIV pre-test counseling form to collect participant characteristics and analyzed HIV test results using Poisson regression and Wilcoxon rank sum trend tests to determine trends over time. We calculated HIV incidence using data from participants who initially tested HIV-negative and tested at least one more time during the program. Confidence intervals for HIV incidence rates were calculated using the Exact Poisson method. From September 2011 through August 2016, 5,629 participants had an HIV test; their median age was 24 years, 1,923 (34%) tested at mobile clinics, 5,609 (99.6%) received their test result, and 1,193 (21%) tested HIV positive. The number of people testing increased from 458 in 2012 to 1,832 in 2016 (p < 0.001). Participants testing at mobile clinics were younger (p < 0.001) and more likely to be testing for the first time (p < 0.001) than those tested at hospitals. Of 1,193 HIV-positive participants, 756 (63%) had CD4 testing. Among 925 participants who returned for HIV testing, HIV incidence was 6.2 per 100 person-years. Incidence was highest among people 20-24 years old (10.9 per 100 person-years). HIV testing among MSM and TG women increased during the PREV program. HIV incidence remains alarmingly high especially among young participants. There is an urgent need to expand HIV prevention services to MSM and TG women in Thailand.

External quality assessment program on CD4+ T-lymphocyte counts for persons with HIV/AIDS in Thailand: history and accomplishments.

A CD4 count External Quality Assessment (EQA) program is important for the clinical monitoring of persons infected with HIV/AIDS. The purpose of the present study was to evaluate the CD4 EQA performance program of the flow cytometer laboratories that perform routine CD4 counts for these patients in Thailand. Stabilized whole blood samples were sent to participating laboratories to determine the percentage and absolute counts of CD4+ T-lymphocytes using their routine procedures. The data were analyzed and reports sent to the participants within one month. Most participating laboratories produced results that were within two standard deviations (SD) of the mean, while the average inter-laboratory coefficients of variation were less than 8% for CD4+ T-lymphocytes. This program was found to improve the reliability of CD4+ T-lymphocyte determinations. This test is becoming increasingly important as Thailand and other Southeast Asian countries scale up their national programs that provide access to antiretroviral therapy for persons living with HIV/AIDS.

Cost savings by reagent reduction in flow cytometry-based CD4+ T cell counts: an approach to improve accessibility for HIV management.

In Thailand, the cost of antiretrovirals has recently been reduced more than 10 fold. Likewise strategies for a cost reduction in laboratory monitoring are warranted. This study was designed to explore if the most expensive reagent in flow cytometry based CD4+ cell monitoring, the CD4+/CD8+ monoclonal antibodies, can be reduced without a loss of accuracy. Blood samples from 55 HIV seronegative (HIV-) and 76 HIV+ subjects were analyzed for %CD4+ and %CD8+ T cells using a two color monoclonal antibody panel (BD Biosciences, CA, USA) with 3 different amounts of the recommended reagents for staining: 1) standard, 2) half, and 3) one-fourth. A significant Spearman correlation of 0.987 was shown for the % CD4+ T cell test results for one half as well as one-fourth of the recommended amount compared to the standard staining according to the manufacturer's instruction (p < 0.0001). For the % CD8+ T cell test results, the correlation between the standard and the half or one-fourth reduced staining was 0.972 (p < 0.0001). Bland-Altman analysis showed no significant bias between the results from one half or one-fourth of the recommended amount versus the standard. The sensitivity and specificity of the two methods at the CD4+ T cell count cut-off of 200 cells/microl were 93% and 100%; and 96% and 99%, respectively. Our study indicates that a reduction of the reagents to half or one-fourth of the amount recommended by the manufacturer was still able to generate reliable results for CD4+ and CD8+ T cell counts. Such an approach will significantly reduce the cost of CD4+ monitoring for resource limited settings where a flow cytometer is available.

A multicenter evaluation of the PanLeucogating method and the use of generic monoclonal antibody reagents for CD4 enumeration in HIV-infected patients in Thailand.

BACKGROUND: The current method of CD4 enumeration in Thailand, based on the three-tube, three-color method recommended by the Centers for Disease Control and Prevention, is expensive and thus unavailable to most patients who have the human immunodeficiency virus (HIV). Less expensive, simpler protocols (i.e., PanLeucogating and primary CD4 gating) have been described but require more published validation data to gain widespread acceptance. We describe a multicenter evaluation of the PanLeucogating method. METHODS: The PanLeucogating method using generic reagents was evaluated in comparison with the standard three-tube, three-color method using commercial reagents. Percentage of CD4+ T cells among lymphocytes and absolute CD4+ T-cell counts were determined in 611 HIV-infected individuals recruited from four sites. Linear regression and Bland-Altman tests were used for statistical analysis. RESULTS: The correlation of percentage of CD4+ T cells and absolute CD4+ T-cell counts obtained with the PanLeucogating strategy and the standard predicate method was high (r2 = 0.96 and 0.95, respectively, for the entire study population and r2 > 0.95 and 0.93, respectively, for each study group). Absolute CD4+ T-cell counts of the overall study pool and of the two subdivisions of absolute CD4+ T-cell counts (i.e., 0-250 cells/microl and > 250 cells/microl) derived from the two methods demonstrated excellent agreement, with mean biases of +18 cells/microl, +11 cells/microl, and +24 cells/microl, respectively. CONCLUSIONS: These observations demonstrate that CD4 enumeration by PanLeucogating is reliable and can be performed to an identical standard in a quality-assured network of collaborating laboratories as a new cost-effective approach to HIV monitoring.