Deficiency of mannose-binding lectin is a risk of Pneumocystis jirovecii pneumonia in a natural history cohort of people living with HIV/AIDS in Northern Thailand.

BACKGROUND: Mannose-binding lectin (MBL) plays a pivotal role in innate immunity; however, its impact on susceptibility to opportunistic infections (OIs) has not yet been examined in a natural history cohort of people living with HIV/AIDS. METHODS: We used archived samples to analyze the association between MBL expression types and risk of major OIs including Pneumocystis jirovecii pneumonia (PCP), cryptococcosis, talaromycosis, toxoplasmosis, and tuberculosis in a prospective cohort in Northern Thailand conducted from 1 July 2000 to 15 October 2002 before the national antiretroviral treatment programme was launched. RESULTS: Of 632 patients, PCP was diagnosed in 96 (15.2%) patients, including 45 patients with new episodes during the follow-up period (1006.5 person-years). The total history of PCP was significantly associated with low MBL expression type: high/intermediate (81/587, 13.8%), low (10/33, 30.3%) and deficient (5/12, 41.7%) (p = 0.001), whereas the history of other OIs showed no relation with any MBL expression type. Kaplan-Meier analysis (n = 569; log-rank p = 0.011) and Cox's proportional hazards model revealed that deficient genotype dramatically increased the risk of PCP, which is independent upon sex, age, CD4 count, HIV-1 viral load and hepatitis B and C status (adjusted hazard ratio 7.93, 95% confidence interval 2.19-28.67, p = 0.002). CONCLUSIONS: Deficiency of MBL expression is a strong risk factor determining the incidence of PCP but not other major OIs.

Evaluation of HIV-1 neutralizing and binding antibodies in maternal-infant transmission in Thailand.

Despite anti-retroviral therapy (ART) interventions for HIV+ pregnant mothers, over 43,000 perinatal infections occur yearly. Understanding risk factors that lead to mother-to-child transmission (MTCT) of HIV are critical. We evaluated maternal and infant plasma binding and neutralizing antibody responses in a drug-naïve, CRF01_AE infected MTCT cohort from Thailand to determine associations with transmission risk. Env V3-specific IgG and neutralizing antibody responses were significantly higher in HIV- infants, as compared to HIV+ infants. In fact, infant plasma neutralizing antibodies significantly associated with non-transmission. Conversely, increased maternal Env V3-specific IgG and neutralizing antibody responses were significantly associated with increased transmission risk, after controlling for maternal viral load. Our results highlight the importance of evaluating both maternal and infant humoral immune responses to better understand mechanisms of protection, as selective placental antibody transport may have a role in MTCT. This study further emphasizes the complex role of Env-specific antibodies in MTCT of CRF01_AE HIV.

Long term renal function in Asian HIV-1 infected adults receiving tenofovir disoproxil fumarate without protease inhibitors.

OBJECTIVES: The risk of kidney dysfunction on the WHO recommended first line regimens containing tenofovir disoproxil fumarate (TDF) without protease inhibitors (PI) remains unclear in Asian patients, especially those with low body weight. METHODS: Using data collected in a multicenter clinical trial in Thailand and proportional hazard regression models, we compared the risk of a >25% estimated glomerular filtration rate (eGFR) reduction in HIV naïve patients initiating TDF or zidovudine (AZT) containing non-PI regimen. RESULTS: Of 640 patients included in the analysis, 461 (72%) received a TDF-containing regimen for a median 6.7 years and 179 (28%) an AZT-containing regimen for 6.5 years. The risk of a >25% eGFR reduction was not associated with treatment (HR 1.11, 95% CI 0.84-1.47, P = 0.46). In multivariate analysis, the risk of >25% eGFR reduction form baseline was associated with body weight at baseline (HR 2.12, 95% CI 1.48-3.02 for <48 kg patients and HR 1.64, 95% CI 1.20-2.25 for 48-59.9 kg patients, compared to those with >60 kg, P < 0.001) and hypertension (HR 4.03, 95% CI 2.0-8.0, P < 0.001). The effect of baseline weight on >25% eGFR reduction did not significantly vary with treatment (P = 0.27). CONCLUSIONS: The risk of eGFR reduction was not higher on TDF- versus AZT-based non-PI regimens. Although the risk of eGFR reduction was greater for patients of lower body weight, this risk was not significantly increased by TDF.

Changes in risk behaviors among Thai men who have sex with men and transgender women enrolled in the test and treat cohort.

The test-and-treat approach has the potential to reduce high-risk sexual behaviors by linking high-risk individuals to health education, although this has not been proven yet. We used longitudinal data from the Test and Treat Demonstration Project among Thai men who have sex with men (MSM) and transgender women (TGW) who were not known to be HIV-positive to analyze changes in risk behaviors during the 24-month study period categorized by three groups: HIV-negative without seroconversion, seroconverters, and HIV-positive at enrollment. Five binary risk behavior outcomes - laboratory-diagnosed sexually transmitted infections (STIs); multiple sexual partners, unprotected anal intercourse, self-perceived HIV risk, and amphetamine-type stimulants use in the past month - were assessed. Among 689 participants, with a mean (SD) age of 23.1 (6.2) years, 165 participants were diagnosed with HIV: 115 at enrollment and 50 with seroconversions. HIV-positive participants at enrollment showed significant reductions in all five behavioral risk outcomes. Seroconverters demonstrated higher risks at enrollment than HIV-negative participants, and continued to practice high-risk behaviors even after seroconversion despite a significant reduction in self-perceived moderate-to-high HIV risk. Continuation of risk behaviors among seroconverters could negatively affect the ending AIDS goal, thus the integration of other effective preventive measures into HIV/STIs management programs are needed.

High subsequent and recurrent sexually transmitted infection prevalence among newly diagnosed HIV-positive Thai men who have sex with men and transgender women in the Test and Treat cohort.

We determined subsequent and recurrent sexually transmitted infections (STIs) among men who have sex with men (MSM) and transgender women (TGW) in the Test and Treat cohort. Thai MSM and TGW adults with previously unknown HIV status were enrolled and tested for HIV. Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and syphilis were tested at baseline, month 12, and month 24 to identify subsequent STIs (any STIs diagnosed after baseline) and recurrent STIs (any subsequent STIs diagnosed among those with positive baseline STIs). Among 448 participants, 17.8% were HIV-positive, the prevalence of subsequent STIs and recurrent STIs was 42% (HIV-positive versus HIV-negative: 66.3% versus 36.7%, p < 0.001) and 62.3% (81% versus 52.5%, p < 0.001), respectively. Common subsequent STIs by anatomical site were rectal CT infection (21.7%), rectal NG infection (13.8%), pharyngeal NG infection (13.1%), and syphilis (11.9%). HIV-positive status was associated with both subsequent STIs (adjusted hazard ratio [aHR] 2.38; 95%CI 1.64-3.45, p < 0.001) and recurrent STIs (aHR 1.83; 95%CI 1.16-2.87, p = 0.01). The results show that newly diagnosed HIV-positive MSM and TGW were at increased risk of STIs despite being in the healthcare system. STI educational counseling is necessary to improve STI outcomes among MSM and TGW in both HIV prevention and treatment programs.

Sexually transmitted infections and HIV RNA levels in blood and anogenital compartments among Thai men who have sex with men before and after antiretroviral therapy: implication for Treatment as Prevention programme.

INTRODUCTION: Sexually transmitted infections (STIs) are common among HIV-positive men who have sex with men (MSM). There have been concerns that undiagnosed and untreated STIs could undermine efforts to use antiretroviral therapy (ART) for prevention due to genital secretion infectiousness. We evaluated the correlation between STIs and HIV RNA in anogenital compartments among HIV-positive MSM before and after ART. METHODS: MSM participants newly diagnosed with HIV were offered ART regardless of CD4 count during November 2012 to November 2015. Syphilis serology, oropharyngeal swab, rectal swab, urine collection for gonorrhoea and chlamydia nucleic acid amplification testing, and HIV RNA measurement in blood, semen and rectal samples were performed at baseline, 12 and 24 months thereafter. RESULTS: Of 143 HIV-positive MSM, 16.1% had syphilis, 23.1% had gonorrhoea and 32.8% had chlamydia at baseline. Participants with STIs at baseline had higher median HIV RNA levels in blood plasma (p = 0.053), seminal plasma (p = 0.01) and rectal secretions (p = 0.002) than those without STIs. Multivariate models identified HIV RNA 100,000 to 500,000 (OR 6.74, 95% CI 2.24 to 20.28, p = 0.001) and >500,000 (OR 9.39, 95% CI 1.08 to 81.72, p = 0.04) copies/mL in blood, CD4 count <350 cells/mm3 (OR 4.20, 95% CI 1.05 to 16.70, p = 0.04) and having any STIs (OR 2.62, 95% CI 1.01 to 6.80 p = 0.047) to be associated with detectable (>40 copies/mL) seminal plasma HIV RNA. Having chlamydia at any sites (OR 3.17, 95% CI 1.07 to 9.44, p = 0.04) was associated with detectable rectal HIV RNA. Incidences of syphilis, gonorrhoea and chlamydia were 13.4, 16.4 and 18.1 per 100 person-years respectively. Nine participants had detectable HIV RNA (five in blood, one in semen, two in rectal samples and one in both blood and rectal samples) at 12 and/or 24 months after ART. CONCLUSIONS: STIs were extremely common among HIV-positive MSM prior to and after ART. ART effectively reduced HIV RNA in all compartments. The correlation between STIs and anogenital HIV RNA, especially prior to ART and likely until complete HIV RNA suppression from ART is achieved, points to the importance of integrating asymptomatic STIs screening into Treatment as Prevention programme for MSM.

Impact of HLA Allele-KIR Pairs on Disease Outcome in HIV-Infected Thai Population.

BACKGROUND: Class I human leukocyte antigen (HLA) molecules contribute to HIV control through antigen presentation to both cytotoxic T lymphocytes and natural killer cells. Contribution of cytotoxic T lymphocytes to HIV clinical outcome by HLA alleles has been well studied. However, reports about the role of natural killer cells in HIV clinical outcome, particularly, about the effect of HLA-killer immunoglobulin-like receptor (KIR) pairs, remain incomplete. METHODS: The effects of HLA allele-KIR pairs on HIV clinical outcome were statistically analyzed in a Thai cohort of treatment-naive chronically infected population (n = 209). RESULTS: Five HLA allele-KIR pairs scored significantly in viral load (VL) differences. Among them, opposing effects on VL were identified among subjects expressing KIR2DL2 ligands within the HLA-C1 group: higher VL in individuals expressing HLA-B*46:01+KIR2DL2+ compared with individuals without KIR (HLA-B*46:01+KIR2DL2-) (5.0 vs 4.6 log10 copies/mL, P = 0.02), in HLA-C*01:02+KIR2DL2+ (5.0 vs 4.6 log10 copies/mL; P = 0.02), and lower VL in HLA-C*12:03+KIR2DL2+ (4.3 vs 5.6 log10 copies/mL; P = 0.01). In the longitudinal analysis of a ten-year follow-up, HLA-B*46:01+KIR2DL2+ve subjects also had a higher mortality rate compared with the subjects without that pair, independent of variables including antiretroviral treatment, as well as CD4 T-cell count, sex, and age (adjusted hazard ratio 5.9, P = 0.02). CONCLUSION: We identified several HLA allele-KIR pairs associated with clinical outcome differences including opposing effects on VL within 1 HLA group with the same KIR. Among them, HLA-B*46:01 emerged in Southeast Asia about 50,000 years ago and is now the most prevalent HLA-B allele in that area. These findings highlight that each endemic area has unique features of anti-HIV innate immunity that impact clinical outcome.

Regional Differences in the Prevalence of Major Opportunistic Infections among Antiretroviral-Naïve Human Immunodeficiency Virus Patients in Japan, Northern Thailand, Northern Vietnam, and the Philippines.

To identify regional differences in the distribution of opportunistic infections (OIs) among human immunodeficiency virus (HIV)-infected patients in Asia, the medical records of antiretroviral therapy (ART)-naïve patients who attended the following tertiary hospitals from 2003 to 2011 were reviewed: Nagoya Medical Center (NMC, Nagoya, Japan), Lampang Hospital (LPH, Lampang, northern Thailand), Bach Mai Hospital (BMH, Hanoi, northern Vietnam), and Philippine General Hospital (PGH, Manila, Philippines). Logistic regression analyses were performed to identify associations between country of origin and risk of major OIs. In total, 1,505 patients were included: NMC, N = 365; LPH, N = 442; BMH, N = 384; and PGH, N = 314. The median age was 32 years, and 73.3% of all patients were male. The median CD4 count was 200 cells/µL. Most patients at NMC and PGH were men who have sex with men. Injection drug users were most common at BMH (35.7%). Mycobacterium tuberculosis (TB) was most common at PGH (N = 75) but was rare at NMC (N = 4). Pneumocystis pneumonia (PCP) prevalence was highest at NMC (N = 74) and lowest at BMH (N = 13). Multivariable logistic regression showed increased odds of TB at PGH (adjusted odds ratio [aOR] = 42.2, 95% confidence interval [CI] = 14.6-122.1), BMH (aOR = 12.6, CI = 3.9-40.3), and LPH (aOR = 6.6, CI = 2.1-21.1) but decreased odds of PCP at BMH (aOR = 0.1, CI = 0.04-0.2) and LPH (aOR = 0.2, CI = 0.1-0.4) compared with those at NMC. The cryptococcosis risk was increased at LPH (aOR = 6.2, CI = 0.9-41.0) compared with that at NMC. Cytomegalovirus (CMV) retinitis prevalences were similar in all countries. OI prevalence remained high among ART-naïve patients in our cohort. The risks of TB, PCP, and cryptococcosis, but not CMV retinitis, differed between countries. Improved early HIV detection is warranted.

The effect of KIR2D-HLA-C receptor-ligand interactions on clinical outcome in a HIV-1 CRF01_AE-infected Thai population.

OBJECTIVE: Class I human leukocyte antigen (HLA) alleles interact with both cytotoxic T lymphocytes through their T-cell receptors, and natural killer cells through their killer immunoglobulin-like receptors (KIRs). Compared with the reported protective effect of KIR3DL1/S1-HLA-Bw4 interactions in HIV-infected patients, the effect of KIR2D-HLA-C combinations on HIV control remains unclear. Here, we investigate the effect of KIR2D-HLA-C combinations on HIV disease progression. DESIGN: We performed a cross-sectional and longitudinal analysis of a Thai HIV cohort. METHODS: Two hundred and nine HIV-1 CRF01_AE-infected, treatment-naive Thai patients (CD4 T-cell counts of >200/µl) and 104 exposed seronegatives were studied. The effect of KIR-HLA receptor-ligand combinations on viral transmission and survival rate was statistically analyzed. RESULTS: We found the following results: higher frequency of patients expressing both KIR2DL3 and HLA-C1 among infected patients compared with exposed seronegative (odds ratio 4.8, P = 0.004), higher viral load in patients expressing HLA-C1 with KIR2DL3 compared with those without this receptor-ligand combination (median 4.8 vs. 4.2 log copies/ml, P = 0.033), higher numbers of KIR2DL3-HLA-C1 interactions was associated with a higher viral load (ß = 0.13, P = 0.039 by linear regression model), and higher mortality rate in carriers of the KIR2DL3-HLA-C1 combination (adjusted hazard ratio 1.9, P = 0.012 by Cox hazard model). CONCLUSION: We have identified a deleterious effect of the KIR2DL3-HLA-C1 receptor-ligand combination on HIV clinical outcomes in a Thai cohort. Further investigation into mechanisms underlying this susceptibility may aid the understanding of the role of natural killer cells in HIV disease control and pathogenesis.

Incidence and predictors of regimen-modification from first-line antiretroviral therapy in Thailand: a cohort study.

BACKGROUND: Antiretroviral therapy markedly reduced mortality in HIV-infected individuals. However, in the previous studies, up to 50% of patients are compelled to modify their regimen in middle and low-income countries where salvage drug is still limited. This cohort study aimed to investigate the incidence and predictors of regimen modification from the first-line antiretroviral regimen in northern Thailand. METHODS: All HIV-infected patients starting antiretroviral therapy (ART) with generic drug (GPOvir®; stavudine, lamivudine and nevirapine) at a governmental hospital in northern Thailand from 2002 to 2007 were recruited. Baseline characteristics and detailed information of regimen modification until the end of 2010 were ascertained from cohort database and medical charts. As a potential genetic predictor of regimen modification, HLA B allele was determined by bead-based array hybridization (WAKFlow® HLA typing kit). We investigated predictors of the regimen modification using Cox's proportional hazard models. RESULTS: Of 979 patients, 914 were eligible for the analysis. The observed events of regimen modification was 377, corresponding to an incidence 13.8/100 person-year-observation (95% CI:12.5-15.3) over 2,728 person years (PY) follow up. The main reasons for regimen modification were adverse effects (73.5%), especially lipodystrophy (63.2%) followed by rash (17.7%). Sixty three patients (17.1%) changed the regimen due to treatment failure. 2% and 19% of patients had HLA-B*35:05 and B*4001, respectively. HLA-B*35:05 was independently associated with rash-related regimen modification (aHR 7.73, 95% CI:3.16-18.9) while female gender was associated with lipodystrophy (aHR 2.11, 95% CI:1.51-2.95). Female gender (aHR 0.54, 95% CI: 0.30-0.96), elder age (aHR 0.56, 95% CI: 0.32-0.99) and having HLA-B*40:01 (aHR 0.29, 95% CI: 0.10-0.82) were protective for treatment failure related modification. CONCLUSION: HLA-B*35:05 and female gender were strong predictors of regimen modification due to rash and lipodystrophy, respectively. Female gender, elder age, and having HLA-B*40:01 had protective effects on treatment failure-related regimen modification. This study provides further information of regimen modification for future tailored ART in Asia.

HLA-B*35: 05 is a protective allele with a unique structure among HIV-1 CRF01_AE-infected Thais, in whom the B*57 frequency is low.

OBJECTIVE: To identify protective human leukocyte antigen (HLA) alleles in an HIV-infected south-east Asian population, in whom HLA-B*57 prevalence is lower than other ethnic groups, and HIV-1 CRF01_AE is the dominant circulating subtype. DESIGN: Cross-sectional study of Thai patients with chronic HIV infection. METHODS: Five hundred and fifty-seven HIV-1 CRF01_AE-infected Thais were recruited. Their HLA type and viral load were determined to statistically analyze the association of each allele in viral control. In-silico molecular dynamics was also used to evaluate the effect of HLA structure variants on epitope binding. RESULTS: HLA-B*35:05 was identified as the most protective allele (P=0.003, q=0.17), along with HLA-B*57:01 (P=0.044, q=0.31). Structurally, HLA-B*35:05 belonged to the HLA-B*35-PY group of HLA-B*35 alleles; however, unlike the other HLA-B*35 alleles that carry Arg (R) at residue 97, it has unique sequences at T94, L95, and S97, located within the peptide-binding groove. Analysis of the three-dimensional HLA structure and molecular dynamics indicates that S97 in HLA-B*35:05 leads to less flexibility in the groove, and shorter distances between the α-helixes compared with the disease-susceptible HLA-B*35-PY allele, HLA-B*35:01. CONCLUSION: These data indicate the existence of a protective effect of HLA-B*57 across ethnic groups and highlight HLA-B*35:05 as an allele uniquely protective in subtype CRF01_AE-infected Thais. The divergence of HLA-B*35:05 from conventional HLA-B*35-PY structural sequences at the peptide-binding groove is consistent with previous studies that have identified HLA residue 97 as strongly influential in shaping HLA impact on immune control of HIV, and that a more restricted peptide-binding motif may be associated with improved control.

Changing burden of HIV/AIDS to clinical settings in Northern Thailand over 15 years.

We conducted a hospital-based descriptive study to describe the changing pattern of patient numbers, characteristics, and mortality rates among human immunodeficiency virus (HIV)-infected patients in northern Thailand over 15 years. The survival status on October 31, 2010 of all HIV-infected adults who attended an HIV center in a government hospital between 1995 and 2010 was ascertained. In total, 3,706 patients were registered, 2,118 (57.2%) of which were male. The survival status of 3,439 patients (92.9%) was available. In addition, 1,543 deaths were identified out of 12,858 person-year-observations (PYO) resulting in a mortality rate of 12.4 deaths/100 PYO (95% confidence interval [CI], 11.3-13.0). An initial decline in mortality rates was observed prior to 1999, probably because of an increase in the proportion of less symptomatic patients. After the introduction of the national highly active antiretroviral therapy (HAART) program, a profound decline in mortality rates was observed, reaching 2.0 deaths/100 PYO (95% CI, 1.4-2.9) in 2010. Simultaneously, the number of patients on follow-up increased by nearly fourfold. Although HAART has drastically improved the survival of HIV-infected patients, the number of patients receiving therapy at this HIV clinic has substantially increased. While referral of HIV patients to general physicians' care should be urged, we cannot overemphasize the importance of preventing new HIV infections.

Switching HIV treatment in adults based on CD4 count versus viral load monitoring: a randomized, non-inferiority trial in Thailand.

BACKGROUND: Viral load (VL) is recommended for monitoring the response to highly active antiretroviral therapy (HAART) but is not routinely available in most low- and middle-income countries. The purpose of the study was to determine whether a CD4-based monitoring and switching strategy would provide a similar clinical outcome compared to the standard VL-based strategy in Thailand. METHODS AND FINDINGS: The Programs for HIV Prevention and Treatment (PHPT-3) non-inferiority randomized clinical trial compared a treatment switching strategy based on CD4-only (CD4) monitoring versus viral-load (VL). Consenting participants were antiretroviral-naïve HIV-infected adults (CD4 count 50-250/mm(3)) initiating non-nucleotide reverse transcriptase inhibitor (NNRTI)-based therapy. Randomization, stratified by site (21 public hospitals), was performed centrally after enrollment. Clinicians were unaware of the VL values of patients randomized to the CD4 arm. Participants switched to second-line combination with confirmed CD4 decline >30% from peak (within 200 cells from baseline) in the CD4 arm, or confirmed VL >400 copies/ml in the VL arm. Primary endpoint was clinical failure at 3 years, defined as death, new AIDS-defining event, or CD4 <50 cells/mm(3). The 3-year Kaplan-Meier cumulative risks of clinical failure were compared for non-inferiority with a margin of 7.4%. In the intent to treat analysis, data were censored at the date of death or at last visit. The secondary endpoints were difference in future-drug-option (FDO) score, a measure of resistance profiles, virologic and immunologic responses, and the safety and tolerance of HAART. 716 participants were randomized, 356 to VL monitoring and 360 to CD4 monitoring. At 3 years, 319 participants (90%) in VL and 326 (91%) in CD4 were alive and on follow-up. The cumulative risk of clinical failure was 8.0% (95% CI 5.6-11.4) in VL versus 7.4% (5.1-10.7) in CD4, and the upper-limit of the one-sided 95% CI of the difference was 3.4%, meeting the pre-determined non-inferiority criterion. Probability of switch for study criteria was 5.2% (3.2-8.4) in VL versus 7.5% (5.0-11.1) in CD4 (p=0.097). Median time from treatment initiation to switch was 11.7 months (7.7-19.4) in VL and 24.7 months (15.9-35.0) in CD4 (p=0.001). The median duration of viremia >400 copies/ml at switch was 7.2 months (5.8-8.0) in VL versus 15.8 months (8.5-20.4) in CD4 (p=0.002). FDO scores were not significantly different at time of switch. No adverse events related to the monitoring strategy were reported. CONCLUSIONS: The 3-year rates of clinical failure and loss of treatment options did not differ between strategies although the longer-term consequences of CD4 monitoring would need to be investigated. These results provide reassurance to treatment programs currently based on CD4 monitoring as VL measurement becomes more affordable and feasible in resource-limited settings. TRIAL REGISTRATION: ClinicalTrials.govNCT00162682 Please see later in the article for the Editors' Summary.

The effect of HLA polymorphisms on the recognition of Gag epitopes in HIV-1 CRF01_AE infection.

INTRODUCTION: The design of a globally effective vaccine rests on the identification of epitopes capable of eliciting effective cytotoxic T lymphocyte (CTL) responses across multiple HIV clades in different populations. This study aims to discern the effect of HLA polymorphisms and the cross-clade reactivity or clade-specificity of epitopes in Thailand where HIV-1 CRF01_AE is circulating. MATERIALS AND METHODS: 14 peptides based on consensus HIV-1 CRF01_AE amino acid sequences were designed for use in IFN-γ ELISpot assays and (51)Cr release assays among 66 HIV-1 CRF01_AE-infected Thai patients. For ELISpot responders carrying HLA alleles currently unknown to restrict CRF01_AE epitopes, in silico epitope-HLA prediction was performed. RESULTS: 29/66 (43.9%) patients recognized at least one peptide. In total 79 responses were seen against all 14 peptides. 28/79 (35.4%) of the responses were in patients with HLA alleles previously reported to restrict CRF01_AE epitopes, 24/79 (30.4%) responses were in individuals with HLA alleles previously reported to restrict epitopes of HIV clades other than CRF01_AE, and the remaining 27/79 (34.2%) responses were not associated with HLA alleles previously known to restrict HIV epitopes. In silico epitope prediction detected 19 novel, epitope-HLA combinations, and 11/19 (57.9%) were associated with HLA-C alleles. We further confirmed a novel HLA restriction of a previously identified HIV-1 Gag epitope [p24(122-130): PPIPVGDIY (PY9)] by HLA-B*40:01 with a standard (51)Cr release assay. DISCUSSION: CTL recognition sites in HIV-1 Gag were similar among different clades but the HLA restriction differed in Thai patients. This disparity in HLA restriction along different populations illustrated the importance of clade- and population-specific HLA analysis prior to CTL vaccine design.

Diagnostic value of two rapid immunochromatographic tests for suspected tuberculosis diagnosis in clinical practice.

OBJECTIVE: To evaluate and compare the diagnostic value of two immunochromatographic tests for tuberculosis (ICT-TB) in clinical practice. MATERIAL AND METHOD: The present extended cross-sectional study investigated suspected active TB patients at Maesai district hospital, and Lampang regional hospital between April 2009 and May 2010. Subjects underwent two commercial ICT-TB serum tests including: an endogenous ICT-TB, a local made test coated with 38 kD, 16 kD, and 6 kD antigens; and an exogenous ICT-TB, an imported test coated with 38 kD and lipoarabinomanan [LAM] antigens. All subjects received two months of follow up. RESULTS: Of 401 patients, 146 (36.4%) had active TB, and 206 (51.4%) were HIVseropositive. An endogenous ICT-TB was superior to an exogenous ICT-TB in all diagnostic values measured except for specificity. In all patients, sensitivity was low, 35.6% (95% CI: 30.9-40.3) in an endogenous ICT-TB vs. 13.7% (95% CI: 10.3-17.1) in an exogenous ICT-TB. The specificity was high and equivalent in both tests, 93.7% (95%CI: 91.4-96.1). Higher diagnostic values were found among human immunodeficiency virus (HIV) seronegatives than in HIV seropositives when unadjusted for CD4+ cell count level. The likelihood ratios (LHR) were higher in patients with CD4+ cell count over 200 cells/microL than for the HIV seronegative group (LHR+ 7.6 vs. 4.8 in an endogenous ICT-TB, and 2.5 vs. 1.9 in an exogenous ICT-TB). CONCLUSION: For the present study setting, an endogenous ICT-TB can be a meaningful tool for first-line testing to rule in TB suspected cases. Subgroups of HIV seronegative and HIV seropositive patients with CD4+ cell count over 200 cells/microL may be expected to benefit most from the test.

Diagnostic value of an immunochromatographic test over clinical predictors for tuberculosis in HIV patients.

PURPOSE: The value of an immunochromatographic test for tuberculosis (ICT-TB) combined with clinical predictors has yet to be evaluated in Thailand. This study aimed to assess any additional diagnostic value of an ICT-TB test over that of clinical predictors in a group of human immunodeficiency virus (HIV) patients as well as in subgroups of HIV patients classified by clinical risk scores. PATIENTS AND METHODS: An extended cross-sectional study was conducted at a community hospital in Chiang Rai and a general hospital in Lampang. HIV patients registered between April 2009 and May 2010 were screened by a locally made ICT-TB test, including 38, 16, and 6 kD Microbacterium tuberculosis antigens, as well as by routine evaluations for TB diagnosis. Demographic data, medical history, signs, and symptoms were recorded. Participants were followed up for 2 months for final ascertainment of TB diagnosis. RESULTS: Of 206 patients, 37 (18%) had TB. Four clinical predictors were identified: low body mass index (<19 kg/m(2)), prolonged cough (duration >2 weeks), shaking chills (≥1 week), and no use of antiretrovirals. The area under the receiver operating curve was 90.2%; adding the ICT-TB test result increased the area nonsignificantly to 91.6% (P = 0.40). When patients were categorized by risk scores derived from selected clinical predictors into low (scores ≤7) and high (scores >7) TB risk groups, a positive ICT-TB test increased the positive predictive value nonsignificantly in the low risk group (from 12.5% to 27.3%, P = 0.17) and the high risk group (from 78.6% to 80.8%, P = 0.73). CONCLUSION: In this study setting, the ICT-TB test did not enhance TB diagnosis over the four clinical predictors in the overall group or any subgroups of HIV patients classified by clinical risk scores.

Unique CRF01_AE Gag CTL epitopes associated with lower HIV-viral load and delayed disease progression in a cohort of HIV-infected Thais.

Cytotoxic T Lymphocytes (CTLs) play a central role in controlling HIV-replication. Although numerous CTL epitopes have been described, most are in subtype B or C infection. Little is known about CTL responses in CRF01_AE infection. Gag CTL responses were investigated in a cohort of 137 treatment-naïve HIV-1 infected Thai patients with high CD4+ T cell counts, using gIFN Enzyme-Linked Immunospot (ELISpot) assays with 15-mer overlapping peptides (OLPs) derived from locally dominant CRF01_AE Gag sequences. 44 OLPs were recognized in 112 (81.8%) individuals. Both the breadth and magnitude of the CTL response, particularly against the p24 region, positively correlated with CD4+ T cell count and inversely correlated with HIV viral load. The breadth of OLP response was also associated with slower progression to antiretroviral therapy initiation. Statistical analysis and single peptide ELISpot assay identified at least 17 significant associations between reactive OLP and HLA in 12 OLP regions; 6 OLP-HLA associations (35.3%) were not compatible with previously reported CTL epitopes, suggesting that these contained new CTL Gag epitopes. A substantial proportion of CTL epitopes in CRF01_AE infection differ from subtype B or C. However, the pattern of protective CTL responses is similar; Gag CTL responses, particularly against p24, control viral replication and slow clinical progression.

Screening scheme development for active TB prediction among HIV-infected patients.

The objective of this study was to develop and evaluate a simple scoring scheme to screen for active tuberculosis (TB) among HIV-infected patients. Two hundred fifty-seven HIV-infected patients were enrolled in the study between April 2009 and May 2010 from Mae Sai District Hospital and Lampang Regional Hospital. Participants underwent routine evaluations to diagnose TB. Data collection included demographics, medical history, signs and symptoms and laboratory results. Of the 257 HIV-infected patients enrolled, 66 (25.7%) were diagnosed with active TB. Six variables were statistically significant predictors of active TB (p < 0.05): BMI < or = 19 kg/m2, cough > 2 weeks, shaking chills > or = 1 week not taking antiretroviral drugs, a CD4+ cell count level < 200 cells/microl, and had a history of TB. A risk score (ranging from 0 to 16) gave a 92.1% sensitivity of being associated with active TB. A low risk score (< or = 2.0), a moderate risk score (3.0-7.0), and a high risk score (>7.0) gave positive likelihood ratios (LHR+) of 0.04 (95% CI 0.01-0.24), 2.56 (95% CI 1.71-3.85), and 11.72 (95% CI 4.91-27.96), respectively. This screening tool may be useful to identify patients who should have further diagnostic testing for TB, but requires further validation before adoption due to the variability of predicting factors and the prevalence of TB in the target population.

Impact of the National Access to Antiretroviral Program on the incidence of opportunistic infections in Thailand.

The National Access to Antiretroviral Program caused a decline in HIV mortality in Thailand, but its impact on opportunistic infections (OI) remains unknown. The aim of this study was to compare the incidence of different OIs before and after the initiation of highly active antiretroviral therapy (HAART). Data from a prospective cohort at a hospital in northern Thailand were analysed. In total, 704 patients enrolled from July 2000 to October 2002 and not on HAART were followed up until October 2004. In addition, 409 patients who started HAART between April 2002 and January 2004 were followed up for 24 months. The impact of HAART on OIs was analysed using Cox proportional hazard models. HAART was associated with a strong reduction in OIs. The reduction appeared to vary by type: tuberculosis (TB), adjusted hazard ratio (AHR) = 0.2 (95% CI 0.1-0.5); pneumocystis pneumonia (PCP), AHR = 0.03 (95% CI 0.007-0.1); cryptococcal meningitis, AHR = 0.2 (95% CI 0.1-0.5); and penicilliosis, AHR = 0.1 (95% CI 0.06-0.3). In conclusion, HAART was very effective in reducing OIs, especially PCP. TB and cryptococcal meningitis remained frequent in the early phase of antiretroviral drug therapy. More attention to prophylaxis as well as earlier diagnosis and starting treatment for these OIs is recommended.

HLA-associated immune pressure on Gag protein in CRF01_AE-infected individuals and its association with plasma viral load.

BACKGROUND: The human leukocyte antigen (HLA)-restricted cytotoxic T-lymphocyte (CTL) immune response is one of the major factors determining the genetic diversity of human immunodeficiency virus (HIV). There are few population-based analyses of the amino acid variations associated with the host HLA type and their clinical relevance for the Asian population. Here, we identified HLA-associated polymorphisms in the HIV-1 CRF01_AE Gag protein in infected married couples, and examined the consequences of these HLA-selected mutations after transmission to HLA-unmatched recipients. METHODOLOGY/PRINCIPAL FINDINGS: One hundred sixteen HIV-1-infected couples were recruited at a government hospital in northern Thailand. The 1.7-kb gag gene was amplified and directly sequenced. We identified 56 associations between amino acid variations in Gag and HLA alleles. Of those amino acid variations, 35 (62.5%) were located within or adjacent to regions reported to be HIV-specific CTL epitopes restricted by the relevant HLA. Interestingly, a significant number of HLA-associated amino acid variations appear to be unique to the CRF01_AE-infected Thai population. Variations in the capsid protein (p24) had the strongest associations with the viral load and CD4 cell count. The mutation and reversion rates after transmission to a host with a different HLA environment varied considerably. The p24 T242N variant escape from B57/58 CTL had a significant impact on the HIV-1 viral load of CRF01_AE-infected patients. CONCLUSIONS/SIGNIFICANCE: HLA-associated amino acid mutations and the CTL selection pressures on the p24 antigen appear to have the most significant impact on HIV replication in a CRF01_AE-infected Asian population. HLA-associated mutations with a low reversion rate accumulated as a footprint in this Thai population. The novel HLA-associated mutations identified in this study encourage us to acquire more extensive information about the viral dynamics of HLA-associated amino acid polymorphisms in a given population as effective CTL vaccine targets.