Chronic Kidney Disease in a Large National Human Immunodeficiency Virus Treatment Program

Tenofovir disoproxil fumarate (TDF) is associated with a risk of chronic kidney disease (CKD), especially in Asian populations. Data from the Thai national health insurance system was used to assess CKD incidence in patients receiving antiretroviral therapy in real-world practice. We analyzed data from patients who initiated one of the following first-line regimens: zidovudine + lamivudine + nevirapine (AZT + 3TC + NVP); zidovudine + lamivudine + efavirenz (AZT + 3TC + EFV); tenofovir + lamivudine + nevirapine (TDF + 3TC + NVP); tenofovir + lamivudine/emtricitabine + efavirenz (TDF + 3TC/FTC + EFV); and tenofovir +lamivudine +lopinavir/ritonavir (TDF + 3TC + LPV/r). CKD was defined as glomerular filtration rate <60 mL/min/1.73 m2 for >3 months, or a confirmed 2010 WHO diagnosis (ICD-10 code N183, N184, or N185). Death competing risk survival regression models were used. Among 27,313 participants, with a median age of 36.8 years and median follow-up of 2.3 years, 245 patients (0.9%) were diagnosed with CKD (incidence 3.2 per 1000 patient-years; 95% CI 2.8−3.6). Compared with patients receiving AZT + 3TC + NVP, the risk of CKD measured by adjusted sub-distribution hazard ratio (aSHR) was 6.5 (95% CI 3.9−11.1) in patients on TDF + 3TC + LPV/r, 3.8 (95% CI 2.3−6.0) in TDF + 3TC + NVP, and 1.6 (95% CI 1.2−2.3) in TDF + 3TC/FTC + EFV. Among patients receiving TDF, compared with those receiving TDF + 3TC/FTC + EFV, the aSHR was 4.0 (95% CI 2.3−6.8) in TDF + 3TC + LPV/r and 2.3 (95% CI 1.4−3.6) in TDF + 3TC + NVP. TDF was associated with an increased risk of CKD, especially when combined with LPV/r or NVP.

Recommended First-Line Antiretroviral Therapy Regimens and Risk of Diabetes Mellitus in HIV-Infected Adults in Resource-Limited Settings

Objective

The use of some antiretroviral drugs has been associated with a higher risk of diabetes mellitus (DM) in HIV-infected patients, but the risk associated with antiretroviral drug combinations remains unclear. We investigated the association between first-line antiretroviral therapy (ART) regimens, recommended by the World Health Organization (WHO) in 2016, and the risk of DM in adults.

Method

We selected all HIV-infected adults within the Thai National AIDS Program who started a first-line ART regimen consisting the following between October 2006 and September 2013: zidovudine+lamivudine+nevirapine; tenofovir disoproxil fumarate (TDF)+lamivudine+nevirapine; zidovudine+lamivudine+efavirenz; TDF+lamivudine/emtricitabine+efavirenz; zidovudine+lamivudine+ritonavir-boosted lopinavir (LPV/r); or TDF+lamivudine+LPV/r. Diagnosis of DM was defined as having at least 2 of the following characteristics: fasting plasma glucose ≥126 mg/dl, 2010 WHO ICD-10 codes E11-E14, or prescription of antidiabetic drugs. To identify ART regimens associated with DM, we used competing risks regression models that considered mortality without DM as a competing event and adjusted for sex, age, pancreas disease, and stratified by groups defined by a score summarizing the propensity to receive a specific first-line ART regimen.

Results

Data from 35 710 adults (49.1% male; median age, 35.0 years; median follow-up, 2.0 years) were included. In the multivariable analysis with zidovudine+lamivudine+nevirapine as the reference group, a higher risk of DM was observed with TDF+lamivudine/emtricitabine+efavirenz (adjusted sub-distribution hazard ratio [aSHR], 1.6; 95% confidence interval [CI], 1.3–1.9), zidovudine+lamivudine+efavirenz (aSHR, 2.0; 95% CI, 1.7–2.3), and TDF+lamivudine+LPV/r (aSHR, 2.7; 95% CI, 1.9–3.9).

Conclusions

Several of the WHO recommended ART regimens, particularly tenofovir + lamivudine +LPV/r and regimens containing efavirenz, may be associated with an increased risk of DM.

Loss to follow-up and associated factors of patients in the National AIDS Program in Thailand

BACKGROUND

Loss to follow-up (LTFU) is a crucial indicator to evaluate the effectiveness of HIV care and treatment programmes. We assessed the LTFU rate and associated factors of Thai HIV-infected patients who enrolled in the National AIDS Program (NAP) for two periods: prior to (pre-ART) and after starting ART (ART-patients).

METHODS

Thai HIV patients aged ≥15 years enrolled in NAP from 2008 to 2014. Vital status was ascertained by linkage with the National Death Registry. Competing risk models were used to calculate the adjusted sub-distribution hazards (aSHR) for LTFU for pre-ART and ART-patients, with death considered as a competing risk.

RESULTS

A total of 157,026 patients registered in care and were included in analyses. The cumulative incidence of LTFU in pre-ART patients at 1 year was 10.2%, whereas in ART-patients it was 12.8%. Among pre-ART patients, younger age (<30 versus ≥45 years, aSHR 1.60, 95% CI 1.49, 1.72), less advanced HIV stage (aSHR 1.29, 95% CI 1.21, 1.37) and higher CD4⁺ T-cell count (≥350 versus <100, aSHR 6.31, 95% CI 5.74, 6.95) had a higher chance of LTFU. ART-patients with high baseline CD4⁺ T-cell count (CD4 ≥350 versus CD4 <50, aSHR 2.06, 95% CI 1.97, 2.15) and non-advanced HIV stage had increased risk of LTFU.

CONCLUSIONS

Our findings provide new evidence of the LTFU rate in Thai HIV-infected patients in NAP. Emphasis needs to be placed on improving follow-up in all patients with higher CD4⁺ T-cell counts. LTFU will be important to monitor as programmes move to commence ART regardless of CD4⁺ T-cell count.

Attrition and treatment outcomes among adolescents and youths living with HIV in the Thai National AIDS Program

BACKGROUND

There are limited data describing the care outcome of youth living with HIV in Asia. We assessed attrition and treatment outcomes among youths with behaviourly acquired HIV (BIY) and adolescents with perinatally acquired HIV (PIY) who initiated antiretroviral treatment (ART) through the National AIDS Program (NAP) in Thailand.

METHODS

People living with HIV aged 10-24 years who initiated antiretroviral therapy (ART) from 2008 to 2013 through the Thai NAP and who were followed up until 2014 were included in the analysis. We assessed youths initiating ART: BIY aged 15-19 years (BIY1) and BIY aged 20-24 (BIY2) compared against PIY aged 10-14 years. Attrition rates (mortality and loss to follow-up [LTFU]) were calculated and potential associations were assessed using Cox regression. Logistic regression was used to assess associations with treatment failure.

RESULTS

Of 11,954 individuals, 9909 (83%) were BIY with a median follow-up of 2.1 years and 17% were PIY with 4.2 years of follow-up. The median baseline CD4 cell count in BIY was higher (190 vs 154 cells/mm³) compared to PIY. Mortality rates were not significantly different among PIY (2.5 per 100 person years [PY], BIY1 3.1/100 PY and BIY2 2.9/100 PY, P=0.46). Compared to PIY with a crude LTFU rate of 2.9/100 PY, LTFU was higher in BIY1 (13.9/100 PY) and BIY2 (9.5/100 PY), P<0.001 and P<0.001, respectively. At 1 year after initiating ART, 16% experienced virological failure (viral load above 1000 copies/mL). Combined treatment failure and LTFU rates at 1 year after ART were higher among BIY1 (45.0%) and BIY2 (34.4%) compared to PIY (29.9%), P<0.001 and 0.001, respectively.

CONCLUSION

Youth with behaviourally acquired HIV aged 15-19 years had poorer retention rates than older BIY and PIY. Targeted interventions for youth are urgently needed to improve overall treatment outcomes.

Incidence and clinical outcomes of diabetes mellitus in HIV-infected adults in Thailand: a retrospective cohort study

BACKGROUND

Since 2005, Thailand has scaled up one of the largest antiretroviral treatment (ART) programs in South East Asia. Although diabetes mellitus (DM) incidence is increasing in low and middle-income countries, its burden and contributing factors in the HIV infected population are not well known.

METHODS

Using the Thai National AIDS Program data over a period of 8-years, we identified patients diagnosed with DM based on the following records: 1) fasting plasma glucose equal to or greater than 126 mg/dl following the 2013 American Diabetes Association criteria or 2) diagnosis codes E11-E14 of the 2010 WHO International Classification of Diseases, or 3) anti-diabetic drugs. Incidence was the number of new cases divided by that of person-years of follow-up (PYFU). Competing risks survival regression, treating death without DM as a competing event, was used to identify factors associated with DM. The risk of death in patients diagnosed with DM was estimated using Cox regression models.

RESULTS

Data of 763,666 PYFU from 199,707 patients (54.2% male; median age 36.2 years at registration with the program) were available and 8383 cases were diagnosed with DM, resulting in an incidence rate of 11.0 per 1000 PYFU. New DM diagnosis was more likely in men (adjusted sub-distribution hazard ratio 1.2), older patients (compared to patients 18 to 34 years old: 1.8 for 35 to 44; 3.0 for 45 to 59; 3.8 for ≥60), and if ART was initiated (1.3). In 2014, 1313 (16.6%) of 7905 diabetic patients had DM complications (11.5% microvascular complications and 6.9% macrovascular complications). Patients diagnosed with DM were at higher risk of death compared to the others.

CONCLUSIONS

DM incidence was higher in this Thailand cohort of HIV infected adults than in the general population. Risk factors were similar to those in the general population, in addition to starting ART.

The challenges of ending AIDS in Asia: outcomes of the Thai National AIDS Universal Coverage Programme, 2000-2014

OBJECTIVES

We sought to determine Thai National AIDS Program (NAP) outcomes and gaps, and success in reaching the WHO 90:90:90 goals.

METHODS

Retrospective study of treatment outcomes, mortality and loss to follow-up (LTFU), of all individuals aged >15 years who registered to the NAP from 2000 to 2014. We focused outcomes on data from 2008 when the NAP was linked to the death registry.

RESULTS

A total of 429,294 patients registered to the NAP up to November 2014, and 309,313 patients aged >15 years started ART. Median (IQR) age was 37 (31-43) years; 51% were male. From 2008 to 2014, long-term follow-up rates per 100 person-years were 3.2 in those who started ART vs 3.5 in those who did not (P<0.001) and mortality rates per 100 person-years were 3.5 in those who started ART vs 4.9 in those who did not (P<0.001). Mortality reduced from 16% in 2008 to 3% in 2014 for those who started ART. For patients starting treatment since 2000, 87% of those alive and with a recent viral load (VL) result had <50 copies/mL, and 6% had VL ≥1000 copies/mL. In a continuum-of-care analysis from 2008 to 2014, 68% were living and retained on ART, and 46% of diagnosed individuals were virally suppressed at <50 copies/mL.

CONCLUSIONS

In the Thai NAP, death and LTFU are major factors disrupting the care-continuum, and many patients initiate ART with low CD4 cell counts. Rolling out systems for early detection and treatment for all, regardless of CD4 cell count, are essential and under way.

Monitoring HIV Drug Resistance: Early Warning Indicators to Assess Performance of Thailand's Antiretroviral Treatment Program

OBJECTIVE

To describe trends in Thailand's antiretroviral treatment (ART) program performance assessed by HIV drug resistance early warning indicators (EWIs), as recommended by WHO, between 2009 and 2013.

MATERIAL AND METHOD

Seven EWIs were monitored, viral load (VL) testing coverage, VL suppression, retention in ART, lost to follow-up (LTFU), antiretrovirals (ARVs) dispensing practices, on-time pill pick-up, and pharmacy stock-outs. Data from ART adult patients in National Health Security Office Scheme were analyzed except for pharmacy stock-outs, which were reported from hospitals. Aggregated averages were calculated for each EWI. Chi-square for trend was applied to measure significant changes.

RESULTS

By September 2013, 174,284 adults were receiving ART at 929 hospitals. Over time, improvement in VL testing coverage (53.8% in 2009 to 79.8% in 2013) was observed. VL suppression and on-time pill pick up rates were well above 90%. Rates of retention in ART declined from 84.0 to 82.9%, whereas LTFU rates increased from 8.3 to 9.2% (p<0.001). Prescriptions with inappropriate ARVs decreased from 0.32 to 0.10% (p<0.001). Of reporting hospitals, 96.1%, 96.3%, and 96.2% observed no ARVs stock-out between 2011 and 2013.

CONCLUSION

EWI is a useful tool to monitor ART program performance and to identify area where improvement is needed.

Life expectancy after initiation of combination antiretroviral therapy in Thailand

BACKGROUND

Access to combination antiretroviral therapy (cART) has decreased mortality in HIV-positive people. We aimed to estimate the expected additional years of life in HIV-positive Thai people after starting cART through the National AIDS Program (NAP), administered by the Thai National Health Security Office (NHSO).

METHODS

The NHSO database collects characteristics of all Thai HIV-infected patients through the National AIDS Program, including linkage with the National Death Registry for vital status. This study included patients aged ≥15 years at cART initiation between 2008 and 2014. The abridged life table method was used to construct life tables stratified by sex and baseline CD4⁺ T-cell count. Life expectancy was defined as the additional years of life from age at starting cART.

RESULTS

201,688 eligible patients were included in analyses, contributing 618,837 person-years of follow-up. Median CD4⁺ T-cell count was 109 cells/mm³ and median age 37 years. The overall life expectancy after cART initiation at age 20 was 25.4 (95% CI, 25.3, 25.6) years and 20.6 (95% CI, 20.5, 20.7) at age 35 years. Life expectancy at baseline CD4⁺ T-cell count ≥350 cells/mm³ was 51.9 (95% CI, 51.0, 52.9) years for age 20 years and 43.2 (95% CI, 42.4, 44.1) years for age 35 years, close to life expectancy in the general Thai population.

CONCLUSIONS

Increasing life expectancy with higher baseline CD4⁺ T-cell counts supports the guideline recommendations to start cART irrespective of CD4⁺ T-cell count. These results are beneficial to forecast the treatment cost and develop health policies for people living with HIV in Thailand and Asia.

Low-dose versus standard-dose ritonavir-boosted atazanavir in virologically suppressed Thai adults with HIV (LASA): a randomised, open-label, non-inferiority trial

BACKGROUND

Thai patients with HIV have higher exposure to HIV protease inhibitors than do white people and dose reduction might be possible. We compared the efficacy of low-dose with standard-dose ritonavir-boosted atazanavir in virologically suppressed Thai patients with HIV.

METHODS

In this randomised, open-label, non-inferiority trial, we recruited patients aged 18 years or older who were receiving ritonavir-boosted protease-inhibitor-based antiretroviral therapy (ART) with HIV plasma viral loads of less than 50 copies per mL, an alanine aminotransferase concentration of less than 200 IU/L, and a creatinine clearance of at least 60 mL/min from 14 hospitals in Thailand. We excluded patients who had active AIDS-defining disease or opportunistic infections, had a history of an HIV viral load of 1000 copies per mL or more after 24 weeks of any ritonavir-boosted protease-inhibitor-based ART, used concomitant medications that could interact with the study drugs, were pregnant or lactating, had illnesses that might change the effect of the study drugs, or had a history of sensitivity to the study drugs. A biostatistician at the study coordinating centre randomly allocated patients (1:1) to switch the protease inhibitor for oral atazanavir 200 mg and ritonavir 100 mg or for atazanavir 300 mg and ritonavir 100 mg once daily, both with two nucleoside or nucleotide reverse transcriptase inhibitors at recommended doses. Randomisation was done with a minimisation schedule, stratified by recruiting centre, use of tenofovir, and use of indinavir as a component of the preswitch regimen. The primary endpoint was the proportion of patients with viral loads of less than 200 copies per mL at week 48, and we followed up patients every 12 weeks. Treatments were open label, the non-inferiority margin was -10%, and all patients who received at least one dose of study medication were analysed. This trial is registered with ClinicalTrials.gov, number NCT01159223.

FINDINGS

Between July 6, 2011, and Dec 23, 2013, we randomly assigned 559 patients: 279 to receive atazanavir 200 mg and ritonavir 100 mg (low dose) and 280 to atazanavir 300 mg and ritonavir 100 mg (standard dose). At week 48, 265 (97·1%) of 273 in the low-dose group and 267 (96·4%) of 277 in the standard-dose group had viral loads of less than 200 copies per mL (difference 0·68; 95% CI -2·29 to 3·65). Seven (3%) of 273 in the low-dose group and 21 (8%) of 277 in the standard-dose group discontinued their assigned treatment (p=0·01). 46 (17%) of 273 participants in the low-dose group and 97 (35%) of 277 in the standard-dose group had total bilirubin grade 3 or higher toxicity (≥3·12 mg/dL; p<0·0001).

INTERPRETATION

A switch to low-dose atazanavir should be recommended for Thai patients with well controlled HIV viraemia while on regimens based on boosted protease inhibitors.

FUNDING

The National Health Security Office and Kirby Institute for Infection and Immunity in Society.

A Population Pharmacokinetic/Pharmacodynamic Model Predicts Favorable HDL Cholesterol Changes Over the First 5 Years in Children Treated With Current Efavirenz-Based Regimens

Efavirenz use is associated with changes in cholesterol concentrations, but it is unclear whether this effect is related to drug concentrations. Using efavirenz and cholesterol plasma concentrations measured in 87 antiretroviral-naive children in Thailand, we assessed indirect response models to describe the evolution of high- and low-density lipoprotein (HDL, LDL) cholesterol concentrations in relation to efavirenz plasma concentrations over time where efavirenz was assumed to either stimulate cholesterol production or inhibit its elimination. Simulations of cholesterol evolution for children with different average efavirenz concentrations (Cav ) according to their assumed status of "fast" or "slow" metabolizers of efavirenz were performed. At treatment initiation, children's median (interquartile range, IQR) age was 8 years (5 to 10), body mass index z-score 0.01 (-1.05 to 1.44), HDL 31 mg/dL (24 to 44), and LDL 83 mg/dL (69 to 100). Median (IQR) efavirenz Cav was 1.7 mg/L (1.3 to 2.1) during the period of observation. The best model describing the evolution of HDL and LDL cholesterol concentrations over time assumed that efavirenz inhibited their elimination. HDL concentrations increase over 5 years, whereas LDL concentrations increased only during the first 4 months and then returned to baseline levels afterward. Simulations predicted that, after 3 years, HDL would increase to 63 mg/dL in "fast" metabolizers and 97 mg/dL in "slow" metabolizers of efavirenz. The population pharmacokinetic-pharmacodynamic (PK-PD) model shows that favorable HDL cholesterol changes can be expected in children with current efavirenz dosing guidelines over 5 years of treatment.

Guidelines for antiretroviral therapy in HIV-1 infected adults and adolescents 2014, Thailand

New evidence has emerged regarding when to commence antiretroviral therapy (ART), optimal treatment regimens, management of HIV co-infection with opportunistic infections, and management of ART failure. The 2014 guidelines were developed by the collaborations of the Department of Disease Control, Ministry of Public Health (MOPH) and the Thai AIDS Society (TAS). One of the major changes in the guidelines included recommending to initiating ART irrespective of CD4 cell count. However, it is with an emphasis that commencing HAART at CD4 cell count above 500 cell/mm³ is for public health, in term of preventing HIV transmission and personal benefit. In tuberculosis co-infected patients with CD4 cell counts ≤50 cells/mm³ or with CD4 cell counts >50 cells/mm³ who have severe clinical disease, ART should be initiated within 2 weeks of starting tuberculosis treatment. The preferred initial ART regimen in treatment naïve patients is efavirenz combined with tenofovir and emtricitabine or lamivudine. Plasma HIV viral load assessment should be done twice a year until achieving undetectable results; and will then be monitored once a year. CD4 cell count should be monitored every 6 months until CD4 cell count ≥350 cells/mm³ and with plasma HIV viral load <50 copies/mL; then it should be monitored once a year afterward. HIV drug resistance genotypic test is indicated when plasma HIV viral load >1,000 copies/mL while on ART. Ritonavir-boosted lopinavir or atazanavir in combination with optimized two nucleoside-analogue reverse transcriptase inhibitors is recommended after initial ART regimen failure. Long-term ART-related safety monitoring has also been included in the guidelines.

A Randomized Comparison of Second-Line Lopinavir/ Ritonavir Monotherapy versus Tenofovir/Lamivudine/ Lopinavir/Ritonavir in Patients Failing Nnrti Regimens: The HIV Star Study

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Neurocognitive impairment in patients randomized to second-line lopinavir/ritonavir-based antiretroviral therapy vs. lopinavir/ritonavir monotherapy

We compared rates of neurocognitive impairment (NCI) among 93 Thai adults failing non-nucleoside reverse transcriptase inhibitor (NNRTI)-based combination antiretroviral therapy (cART) before and after switching to lopinavir/ritonavir monotherapy (mLPV/r) vs. tenofovir/lamivudine/LPV/r (TDF/3TC/LPV/r). Participants completed the Color Trails 1 and 2, Digit Symbol, and Grooved Pegboard at weeks 0, 24, and 48. We calculated z-scores using normative data from 451 healthy HIV-negative Thais. We defined NCI as performance of <-1 SD on ≥2 tests. The Thai depression inventory was used to capture depressive symptoms. Lumbar puncture was optional at week 0 and 48. At baseline, median (IQR) age was 36.9 (32.8-40.5) years, and 46 % had primary school education or lower. The median CD4 count was 196 (107-292) cells/mm(3), and plasma HIV RNA was 4.1 (3.6-4.5) log(10) copies/ml. Almost all (97 %) had circulating recombinant CRF01_AE. At baseline, 20 (47 %) of the mLPV/r vs. 22 (44 %) of TDF/3TC/LPV/r arms met NCI criteria (p = 0.89). The frequency of NCI at week 48 was 30 vs. 32 % (p = 0.85) with 6 vs. 7 % (p = 0.85) developing NCI in the mLPV/r vs. TDF/3TC/LPV/r arms, respectively. Having NCI at baseline and lower education each predicted NCI at week 48. Depression scores at week 48 did not differ between arms (p = 0.47). Cerebrospinal fluid HIV RNA of <50 copies/ml at 48 weeks was observed in five out of seven in mLPV/r vs. three out of four in TDF/3TC/LPV/r arm. The rates of NCI and depression did not differ among cases failing NNRTI-based cART who received mLPV/r compared to LPV/r triple therapy.

A randomized comparison of second-line lopinavir/ritonavir monotherapy versus tenofovir/lamivudine/lopinavir/ritonavir in patients failing NNRTI regimens: the HIV STAR study

BACKGROUND

Data informing the use of boosted protease inhibitor (PI) monotherapy as second-line treatment are limited. There are also no randomized trials addressing treatment options after failing first-line non-nucleoside reverse transcriptase inhibitor (NNRTI)-regimens.

METHODS

HIV-infected subjects ≥18 years, with HIV RNA≥1,000 copies/ml while using NNRTI plus 2 NRTIs, and naive to PIs were randomized to lopinavir/ritonavir (LPV/r) 400/100 mg twice daily monotherapy (mono-LPV/r) or tenofovir disoproxil fumarate (TDF) once daily plus lamivudine (3TC) twice daily plus LPV/r 400/100 mg twice daily (TDF/3TC/LPV/r) at nine sites in Thailand. The primary outcome was time-weighted area under curve (TWAUC) change in HIV RNA over 48 weeks. The a priori hypothesis was that the mono-LPV/r arm would be considered non-inferior if the upper 95% confidence limit in TWAUC mean difference was ≤0.5 log(10) copies/ml.

RESULTS

The intention-to-treat (ITT) population comprised 195 patients (mono-LPV/r n=98 and TDF/3TC/LPV/r n=97): male 58%, baseline mean (sd) age of 38 (7) years, CD4(+) T-cell count of 204 (135) cells/mm(3) and HIV RNA of 4.1 (0.6) log(10) copies/ml. The majority had HIV-1 recombinant CRF01_AE infection, and thymidine analogue mutation (TAM)-2 was 3× more common than TAM-1. At 48 weeks, the difference in TWAUC HIV RNA between arms was 0.15 (95% CI -0.04, 0.33) log(10) copies/ml, consistent with our definition of non-inferiority. However, the proportion with HIV RNA<50 copies/ml was significantly lower in the mono-LPV/r arm: 61% versus 83% (ITT, P<0.01). Baseline HIV RNA≥5 log(10) copies/ml (P<0.001) and mono-LPV/r use (P=0.003) were predictors of virological failure. Baseline genotypic sensitivity scores ≥2 and TAM-2 were associated with better virological control in subjects treated with the TDF-containing regimen.

CONCLUSIONS

In PI-naive patients failing NNRTI-based first-line HAART, mono-LPV/r had a significantly lower proportion of patients with HIV RNA<50 copies/ml compared to the TDF/3TC/LPV/r treatment. Thus, mono-LPV/r should not be recommended as a second-line option.

Etravirine and rilpivirine resistance in HIV-1 subtype CRF01_AE-infected adults failing non-nucleoside reverse transcriptase inhibitor-based regimens

BACKGROUND

We studied prevalence of etravirine (ETR) and rilpivirine (RPV) resistance in HIV-1 subtype CRF01_AE infection with first-line non-nucleoside reverse transcriptase inhibitor (NNRTI) failure.

METHODS

A total of 225 adults failing two nucleoside reverse transcriptase inhibitors (NRTIs) plus 1 NNRTI in Thailand with HIV RNA>1,000 copies/ml were included. Genotypic resistance results and HIV-1 subtype were interpreted by Stanford DR database. ETR resistance was calculated by the new Monogram weighted score (Monogram WS; ≥ 4 indicating high-level ETR resistance) and by DUET weighted score (DUET WS; 2.5-3.5 and ≥ 4 resulted in intermediate and reduce ETR response, respectively). RPV resistance interpretation was based on previous reports.

RESULTS

Median (IQR) age was 38 (34-42) years, 41% were female and CDC A:B:C were 22%:21%:57%. HIV subtypes were 96% CRF01_AE and 4% B. Antiretrovirals at failure were lamivudine (100%), stavudine (93%), nevirapine (90%) and efavirenz (10%) with a median (IQR) duration of 3.4 (1.8-4.5) years. Median (IQR) CD4(+) T-cell count and HIV RNA were 194 (121-280) cells/mm³ and 4.1 (3.6-4.6) log₁₀ copies/ml, respectively. The common NNRTI mutations were Y181C (41%), G190A (22%) and K103N (19%). The proportion of patients with Monogram WS score ≥ 4 was 61.3%. By DUET WS, 49.8% and 7.5% of patients were scored 2.5-3.5 and ≥4, respectively. Only HIV RNA ≥ 4 log₁₀ copies/ml at failure was associated with both Monogram WS ≥ 4 (OR 2.3, 95% CI 1.3-3.9; P=0.003) and DUET WS ≥ 2.5 (OR 1.9, 95% CI 1.1-3.3; P=0.02). The RVP resistance-associated mutations (RAMs) detected were K101P (1.8%), Y181I (2.7%) and Y181V (3.6%). All patients with RPV mutation had ETR resistance. No E138R/E138K mutations were detected.

CONCLUSIONS

Approximately 60% of patients had high-level ETR resistance. The role of ETR in second-line therapy is limited in late NNRTI failure settings. RVP RAMs were uncommon, but cross-resistance between ETR and RVP was high.

Revisiting the role of neutralizing antibodies in mother-to-child transmission of HIV-1

We analyzed the association between mother-to-child transmission (MTCT) of human immunodeficiency virus type 1 (HIV-1) and maternal neutralizing antibodies to heterologous primary isolates of various HIV-1 clades, to test the hypothesis that protective antibodies are those with broad neutralizing activity. Our study sample included 90 Thai women for whom the timing of HIV-1 transmission (in utero or intrapartum) was known. The statistical analysis included a conditional logistic-regression model to control for both plasma viral load and duration of zidovudine prophylaxis. The higher the titer of neutralizing antibodies to a heterologous strain of the same clade, the lower the rate of MTCT of HIV-1. More specifically, high levels of neutralizing antibodies to the MBA (CRF01_AE) strain were associated with low intrapartum transmission of HIV-1. This suggested that such heterologous neutralizing antibodies may be involved in the natural prevention of late perinatal HIV transmission. These data are consistent with the hypothesis that the use of some antibodies might help to prevent perinatal HIV transmission, through passive immunoprophylaxis. Moreover, the study of humoral factors associated with MTCT of HIV-1 may identify correlates of protection that should help in the design of efficient HIV/acquired immunodeficiency syndrome vaccines.

Long term oral anticoagulant therapy after heart valve prostheses at Siriraj Hospital

One hundred and forty-six cases of cardiac valvular prostheses in the Department of Surgery, Siriraj hospital, were studied retrospectively for the effect of long-term oral anticoagulant therapy. Warfarin sodium was given to 119 patients after operation, 5 cases discontinued therapy and 27 cases received no anticoagulant at all due to loss of follow-up. One stage prothrombin time was used as laboratory control. The advocated therapeutic range for commercial rabbit brain thromboplastin was 1.35-2.2 P.T. ratio. The incidence of thromboembolism was 8.9 per 100 patients - year in the nontherapeutic group, and was 0.6 per 100 patients - year in the therapeutic group (p less than 0.05). Bleeding complications was 26.9 per cent. These were 34 minor-, 11 major-and 2 fatal bleeding episodes. One bleeding manifestation was found in the nontherapeutic group, the etiology was not recorded. The mean dose of warfarin sodium in the thromboembolic group was 2.5 mg/day, this gave a therapeutic ratio of less than 1.4. In the bleeding group that had P.T. ratio not exceeding 2.2, the mean dose was 3.37 mg/day; and 5.23 mg/day when P.T. ratio was higher than 2.2 (p less than 0.01). Therefore, it seems justifiable to conclude that the appropriate mean dose should be over 2.5 mg/day and less than 3.37 mg/day. However, regular blood test to determine the appropriate daily dose for each individual patient is obligatory, as patients might be more or less sensitive to the drug than the average and drug requirement varies from time to time even in the same individual owing to many factors.(ABSTRACT TRUNCATED AT 250 WORDS)