Low-level genital HIV shedding in Thai HIV-infected women with suppressed plasma viral load after menopause: a longitudinal study.

OBJECTIVES: First, to evaluate the longitudinal changes of HIV RNA in genital secretions in HIV-positive women with plasma HIV RNA <50 copies/mL before and after the onset of menopause. Second, to assess inflammatory markers and prevalence of comorbidities after the onset of menopause. METHODS: This was a prospective observational study with two time points. HIV RNA in genital secretions (GVL) was measured in 15 HIV-positive menopausal women (second time point). Results were compared to earlier available data for GVL from the same participant before the onset of menopause (first time point). RESULTS: Median age at the first time point was 42 years, and 52 years at the second time point. Median time since the onset of menopause was 2 years and 33% of women were sexually active. Eighty per cent had at least one comorbidity. The GVL before menopause was >50 copies/mL in 27% of the participants, and in 40% after menopause. The GVL was <1000 copies/mL in all but one measurement. There was no significant difference between the two time points (P=0.687). Intermediate vaginal flora or bacterial vaginosis was found in 73% of participants during the second time point. CONCLUSIONS: There was a high prevalence of low-level GVL shedding before and after menopause. This needs further investigation, especially in relation to the vaginal microbiome and the complex interactions between micro-organisms. HIV-infected women in menopause do not seem to present a major public health risk for HIV transmission. Nevertheless, safe sex should be discussed with all, regardless of age. The high prevalence of non-communicable diseases after menopause requires special attention and comprehensive care.

HIV-1 genital shedding in HIV-infected patients randomized to second-line lopinavir/ritonavir monotherapy versus tenofovir/lamivudine/lopinavir/ritonavir.

BACKGROUND: HIV-1 shedding in genital secretions is associated with HIV transmission risk. Limited data exist on the effect of second-line lopinavir/ritonavir monotherapy (mLPV/r) on genital secretion of HIV RNA. METHODS: We measured HIV-1 in genital secretions of HIV-infected adults at time of failure from non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimens and at 48 weeks after being randomized to second-line mLPV/r versus tenofovir/lamivudine/LPV/r (TDF/3TC/LPV/r). Plasma and genital secretion (semen, vaginal swab) HIV RNA was quantified by the CobasAmpliprep/TaqMan assay. RESULTS: Forty enrolled (15 on mLPV/r and 25 on TDF/3TC/LPV/r). Median age was 37.8 years and 35% were male. Median baseline CD4(+) T-cell count was 222 cells/mm(3), plasma HIV RNA was 4.1 log10 copies/ml and genital secretion HIV RNA was 2.3 log10 copies/ml. At week 48, the proportion of patients with plasma HIV RNA<50 copies/ml was 13/15 (87%) in mLPV/r and 21/25 (84%) in TDF/3TC/LPV/r arms. Median genital HIV RNA was significantly decreased from baseline in both arms (P=0.009 in mLPV/r and P=0.001 in TDF/3TC/LPV/r). In subjects with suppressed plasma HIV RNA, 12/34 (35%; 6/13 [46%] in the mLPV/r and 6/21 [29%] in the TDF/3TC/LPV/r arms) had detectable HIV RNA (range 74-957 copies/ml) in the genital secretions (P=0.41). By multivariate analysis, the only predictor of having genital HIV RNA>50 copies/ml at week 48 was baseline genital secretion HIV RNA>50 copies/ml (P=0.049). CONCLUSIONS: LPV/r either given alone or in combination with TDF/3TC as second-line treatment achieved high genital secretion HIV RNA suppression rate. Genital secretion HIV RNA remained detectable at low levels in one-third of patients with suppressed plasma viraemia.

Reduced markers of HIV persistence and restricted HIV-specific immune responses after early antiretroviral therapy in children.

OBJECTIVE: Understanding the extent to which early antiretroviral therapy (ART) can limit the establishment and persistence of the HIV reservoir is an important step to designing interventions aimed at achieving HIV cure. We measured the markers of HIV persistence and HIV-specific immunity in early treated children. DESIGN: This is a cross-sectional study that enrolled 15 children older than 2 years of age who initiated ART before 6 months of age and had sustained viral suppression. Total and integrated HIV DNA, and 2-LTR circles in CD4 T cells, HIV antibody response by fourth generation HIV enzyme immunoassay, and CD4 and CD8 T-cell responses to gag/env peptides by intracellular cytokine staining of CD4 and CD8 T cells were measured. RESULTS: The median current age was 6.3 years and age at ART initiation was 17 weeks. The median duration of viral suppression was 6 years, and all had HIV RNA less than 50 copies/ml. The median CD4 T cells was 44%. The median total HIV DNA was 132 copies/10 CD4 T cells (range 11-1804) and integrated HIV DNA was 17 copies/10 CD4 T cells (range 0-516), and no one had detectable 2-LTR circles. Nine of the 15 children (60%) had undetectable or extremely low integrated HIV DNA (<20 copies/10 CD4 T cells). All except one (93%) had undetectable HIV-specific CD4/CD8 cell responses and seven (47%) had nonreactive enzyme immunoassay. CONCLUSION: Early ART resulted in very low levels of markers of HIV persistence and undetectable HIV-specific immune responses in the majority of HIV-infected children who started ART before 6 months of age.

Cytomegalovirus viremia in Thai HIV-infected patients on antiretroviral therapy: prevalence and associated mortality.

BACKGROUND: Prevalence and risk factors of cytomegalovirus (CMV) viremia in patients infected with human immunodeficiency virus (HIV) starting antiretroviral therapy (ART) in developing countries are understudied. METHODS: We measured CMV DNA in stored plasma specimens of 293 Thai HIV patients starting ART at CD4 counts <200 cells/mm(3). We examined Cox proportional hazard ratios (HRs) of 24 months mortality and new AIDS-defining illness (ADI). RESULTS: Of 293 patients, 159 (54.3%) were male. The median age was 33 years. The median baseline CD4 count was 82 cells/mm(3), and the median HIV-1 RNA was 4.9 log10 copies/mL. In total, 273 (93.2%) patients started potent combination ART, and 20 (6.8%) started dual nucleoside reverse transcriptase inhibitor (NRTI) therapy. CMV DNA was detected in 77 of 293 patients (26.3%) at baseline, and 9 of 199 patients with available specimen (4.5%) after 6 months of ART. The median CMV DNA was 548 copies/mL (interquartile range [IQR], 129-3849) at baseline and 114 copies/mL (IQR, 75-1099) at 6 months. In univariate analysis, death was associated with baseline CDC stage C, hemoglobin <10 g/dL, lower CD4 count, and CMV viremia. In multivariate analysis, only CMV DNA >500 copies/mL was significantly associated with mortality (HR: 7.28; 95% CI, 1.32-40.29, P = .023). CD4 count was the only variable associated with new ADI (HR: 0.70 per 50 CD4 cells increase; 95% CI, .49-.997, P = .048). CONCLUSIONS: In these Thai patients with advanced HIV disease, CMV viremia was frequent, and CMV DNA >500 copies/mL predicted increased mortality despite ART initiation. This calls for increased attention to screening of active CMV infection in advanced HIV patients in developing countries. Trials assessing preemptive anti-CMV therapy may be warranted.

Association of APOBEC3G genotypes and CD4 decline in Thai and Cambodian HIV-infected children with moderate immune deficiency.

INTRODUCTION: Human APOBEC3G is a host defense factor that potently inhibits HIV replication. We hypothesize that HIV-infected children with a genetic variant of APOBEC3G will have a more rapid disease progression. METHODS: Antiretroviral therapy (ART)-naïve children, aged 1-12 years old with CD4 15-24% and without severe HIV-related symptoms were enrolled. The children had CD4% and absolute CD4 counts every 12 weeks and HIV-RNA every 24 weeks until 144 weeks. ART was started when CD4% declined to < 15% or AIDS-related events developed.APOBEC3G genetic variants were performed by PCR-based restriction fragment length polymorphism techniques from peripheral blood mononuclear cells. Random-effect linear regression analysis was performed to correlate APOBEC3G genotypes and disease progression. RESULTS: 147 children, 35% male, with a median (IQR) age of 6.5 (4.3-8.8) years were enrolled. CDC N:A:B were 1:63:36%. Median baseline values were 20% for CD4% 605 cells/mm3 for CD4 count and 4.7 log10copies/mL for HIV-RNA.The frequencies of APOBEC3G genotypes AA (186H/H), AG (186H/R), GG (186R/R) were 86%, 12%, and 2% respectively. The APOBEC3G genotype GG was associated with a significant decline in CD4% -5.1% (-8.9 to -1.2%), p<0.001, and CD4 counts -226 (-415 to -34) cells/mm3, p<0.001 by random-effect liner regression analysis. No significant associations of APOBEC3G genotypes with HIV-RNA changes overtime (p=0.16) or progression to CDC B and C (p=0.49) were observed. CONCLUSIONS: APOBEC3G genotype GG was significantly associated with a more rapid decline in CD4. APOBEC3G's antiviral effects on HIV disease progression in children should be further explored.

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.

High prevalence of lipid abnormalities among antiretroviral-naive HIV-infected Asian children with mild-to-moderate immunosuppression.

BACKGROUND: Dyslipidaemia is a common complication among HIV-infected children after antiretroviral therapy (ART); however, HIV itself can cause abnormal lipid metabolism. There is limited information of lipid profiles among Asian HIV-infected children naive to ART. METHODS: A total of 274 HIV-infected ART-naive Thai and Cambodian children aged 1-12 years with CD4% between 15% and 24% were included. Patients were fasted for ≥4 h before blood was drawn. Abnormal lipid levels were defined as triglyceride (TG)>130 mg/dl, total cholesterol (TC)>200 mg/dl, low-density lipoprotein (LDL)>130 mg/dl and high-density lipoprotein (HDL)≤40 mg/dl. RESULTS: The mean (±SD) was 76.6 (33.8) months for age and -1.3 (1.0) for weight Z-score. Mean (±SD) CD4% was 19.9 (4.8) % and HIV RNA was 4.6 (0.6) log(10) copies/ml. The median (±SD) fasting time was 13.0 (2.7) h. Mean (±SD) for lipids were 116 (62) mg/dl for TG, 139 (29) mg/dl for TC, 73 (29) mg/dl for LDL and 45 (19) mg/dl for HDL. Overall 63.9% had dyslipidaemia with hypertriglyceridaemia and hypo-HDL being the most common (28% and 45%, respectively), while 2% had hypercholesterolaemia or hyper-LDL. After adjusting for age, having HIV RNA>5 log(10) copies/ml was associated with hypo-HDL with ORs of 8.1 (95% CI 2.7-24.3). CONCLUSIONS: Up to two-thirds of ART-naive, HIV-infected Asian children with mild-to-moderate immune suppression had dyslipidaemia. Low HDL was the most common and was associated with high HIV viraemia. The long-term consequence of low HDL deserves further investigation in children.

Safety and efficacy of a double-boosted protease inhibitor combination, saquinavir and lopinavir/ritonavir, in pretreated children at 96 weeks.

BACKGROUND: This study aimed to assess the long-term efficacy, safety and use of therapeutic drug monitoring (TDM) of a double-boosted protease inhibitor (PI) combination, saquinavir (SQV) and lopinavir/ritonavir (LPV/r), in Thai HIV type-1 (HIV-1)-infected children who had failed on reverse transcriptase inhibitors. METHODS: In total, 50 children from two sites in Thailand were treated with standard dosing of SQV and LPV/r. CD4(+) T-cell count and percentage, viral load (VL; HIV-1 RNA), minimum plasma drug concentrations (C(min)) and drug safety laboratory evaluations were monitored. Virological failure was defined as having two consecutive VL measures >400 copies/ml after week 12. An intention-to-treat analysis was performed. RESULTS: Baseline data were a median age of 9.3 years (interquartile range [IQR] 7.1-11.2), VL 4.8 log(10) copies/ml (IQR 4.5-5.1) and CD4(+) T-cell percentage 7% (IQR 3.0-9.5). CDC classifications were N=4%, A=14%, B=68% and C=14% of participants. Median CD4(+) T-cell percentage and CD4(+) T-cell count increase were 14% (IQR 7-19) and 558 cells/mm(3) (IQR 308-782), respectively (both P<0.001). Overall, 37 (74%) children achieved VL<50 copies/ml with significant differences between sites (90% versus 63%). Over 96 weeks, 10 patients had virological failure. Total cholesterol and high-density lipoprotein increased significantly over time, whereas the triglycerides and low-density lipoprotein did not. Approximately 50% of participants reported no change in body shape, and 33%, 43% and 39% reported fatter arms, face and abdomen, respectively. LPV and SQV C(min) were high and stable over time. CONCLUSIONS: Double-boosted SQV+LPV/r was an effective and safe alternative for a second-line regimen in children. Hypercholesterolaemia needs close follow-up. On the basis of the TDM results, PI dose reduction in this population should be considered.

Interruptions of tenofovir/emtricitabine-based antiretroviral therapy in patients with HIV/hepatitis B virus co-infection.

Thai patients enrolled in STACCATO with HIV/hepatitis B virus (HBV) co-infection and tenofovir/emtricitabine-based antiretroviral therapy (ART) were randomly assigned to continuous treatment or CD4 cell count-guided interruptions. HBV replication was suppressed below detection in 15/16 patients. Structured treatment interruption increased transaminases and HBV viraemia in five of six patients; one flare was severe. Conversion to anti-hepatitis Be occurred with continuous treatment only. Tenofovir/emtricitabine-containing ART is highly effective in controlling chronic HIV/HBV co-infection but treatment should not be interrupted.

Supersensitive Viral Load Assay in Predicting CD4-Guided Treatment Failure.

In HIV patients who discontinue highly active antiretroviral therapy (HAART), the degree of HIV RNA suppression at the time of treatment interruption may predict success of re-treatment after the interruption (STI). A case-control substudy of the Staccato trial in Thailand included CD4-guided STI subjects with HIV RNA > 50 copies /ml (virological failure cases, n=11) and HIV RNA < 50 copies/ml (controls, n=22) after 12-24 weeks of HAART re-treatment following a median of 2 STI cycles. Controls were matched for age, gender and pre-ART CD4 count. HIV RNA with 5 copies/ml detection limit was determined on pre-virological failure samples. HIV RNA increased in cases compared to controls with each successive STI cycle (p-trend across time-points 0.004). The last HIV RNA below 50 copies/ml was significantly higher among cases compared to controls (p=.004). Measuring HIV RNA below 50 copies/ml may be useful in predicting virological failure to STI.

The use of pharmacokinetically guided indinavir dose reductions in the management of indinavir-associated renal toxicity.

OBJECTIVES: Indinavir is associated with nephrotoxicity. Therapeutic drug monitoring of indinavir improves clinical outcome, but there is little data regarding therapeutic drug monitoring for patients with established indinavir-associated renal impairment. We prospectively studied the use of therapeutic drug monitoring in patients with virological success but established nephrotoxicity on an indinavir-containing regimen. METHODS: We measured indinavir C(trough)/C(2h), serum creatinine, pyuria, blood pressure (BP), weight and HIV RNA. The major endpoint of interest was the number of patients achieving a normal creatinine level 20 weeks following final indinavir dose adjustment. Primary analysis was by intention to treat (ITT). RESULTS: A total of 35 patients were enrolled; mean (SD) age 40.3 (5.8) years; mean (SD) BMI 21.5 (2.8) kg/m(2). At baseline 6/35 (17%) had a serum creatinine concentration within normal limits, but were offered enrolment because of previous nephrotoxicity (nephrolithiasis and/or abnormal serum creatinine), and a screening pharmacokinetic profile associated with increased nephrotoxicity risk. By ITT analysis 11/35 (31%) had normal creatinine at study end (P = 0.18). Of the 29 patients with abnormal creatinine at baseline, 7/29 (24.1%) had normal creatinine at study end (P = 0.016). Patients had a median (IQR) indinavir per dose adjustment over the study of 400 (400-800) mg. We observed improvements in estimated creatinine clearance, pyuria, resting BP and indinavir pharmacokinetic profile. HIV RNA control was maintained with continued immune recovery despite lower indinavir doses. CONCLUSIONS: Patients experiencing nephrotoxicity on an indinavir-containing regimen were safely maintained on indinavir by means of therapeutic drug monitoring. Parameters of renal function improved but did not return to baseline values, at least in the short-term.

Efavirenz levels and 24-week efficacy in HIV-infected patients with tuberculosis receiving highly active antiretroviral therapy and rifampicin.

BACKGROUND: Concomitant use of efavirenz and rifampicin is common for treatment of HIV and tuberculosis. Plasma efavirenz levels can be reduced by rifampicin, but the appropriate daily dosage of efavirenz is unclear. METHODS: HIV-infected patients with active tuberculosis, receiving rifampicin > 1 month, were randomized to receive stavudine and lamivudine plus efavirenz 600 or 800 mg daily. Plasma efavirenz levels were measured (at 12 h after dosing and on day 14) by high-performance liquid chromatography. Plasma HIV RNA was assessed at 16 and 24 weeks after antiretroviral therapy. RESULTS: Baseline characteristics were comparable in the 84 patients (two groups of 42). Median plasma efavirenz levels were 3.02 mg/l (range, 0.07-12.21) in the 600 mg group and 3.39 mg/l (range, 1.03-21.31) in the 800 mg group (P = 0.632). Plasma efavirenz levels were < 1 mg/l in 3 of 38 (7.9%) patients in the 600 mg group and in none of the 800 mg group (P = 0.274). Approximately 40 and 45% of patients had efavirenz levels > 4 mg/l, respectively. There was no significant difference in time to HIV RNA < 50 copies/ml (P = 0.848). CONCLUSIONS: Median plasma efavirenz levels were comparable among both groups. Efavirenz 600 mg/day should be sufficient for most Thai HIV-infected patients receiving rifampicin with body weight approximately 50 kg. These results may not be applicable to other ethic populations who have higher body weights. However, the study of long-term virological and immunological outcomes is needed and under further investigation.

Highly active antiretroviral therapy (HAART) retreatment in patients on CD4-guided therapy achieved similar virologic suppression compared with patients on continuous HAART: the HIV Netherlands Australia Thailand Research Collaboration 001.4 study.

OBJECTIVE: To assess the safety of 2 intermittent treatment strategies compared with continuous therapy for patients with virologic suppression on highly active antiretroviral therapy (HAART) at baseline. DESIGN: Seventy-four nucleoside reverse transcriptase inhibitor (NRTI) and protease inhibitor (PI) pretreated patients with an HIV RNA level <50 copies at screening were randomized to continuous treatment, CD4-guided treatment, or week-on-week-off treatment with 2 NRTIs plus 1600 mg/100 mg of saquinavir/ritonavir once daily. At week 96 (end of the randomized phase of the study), all patients were given continuous HAART for 12 weeks to week 108. Primary outcomes were the proportion of patients with a CD4 count >350 cells/microL and HIV RNA level <400 copies/mL at week 108. METHODS: Patients were followed up every 12 weeks for CD4 count, HIV RNA level, and clinical and laboratory toxicities. In the CD4-guided arm, treatment was stopped and restarted using a CD4 count threshold (above or below 350 cells/microL or reduction of 30%). RESULTS: Seventy-four patients were enrolled with a median CD4 count of 644 cells/microL before the structured treatment interruption (STI). The week-on-week-off arm (n=26) was discontinued at week 72 because of high rates (46%) of HIV RNA rebound above 50 copies/mL. In the continuous arm, 25 (100%) of 25 patients and 24 (96%) of 25 patients had an HIV RNA level <400 copies/mL and <50 copies/mL, respectively, at week 108, and 96% had a CD4 count above 350 cells/microL, with a median CD4 count of 661 cells/microL. Patients in the CD4-guided arm had a significantly lower median CD4 count (489 cells/microL) than the patients in the continuous arm (P=0.03), but all had a CD4 count above 350 cells/microL and 1 had a new HIV-related illness. At week 108, 21 (91%) of 23 patients and 13 (57%) of 23 patients had an HIV RNA level <400 copies/mL and <50 copies/mL, respectively. Those who did not achieve an HIV RNA level <50 copies/mL had a higher HIV RNA load before retreatment, and 4 of 5 patients subsequently achieved viral suppression after an additional 12 weeks of HAART (week 120). Therefore, 17 (94%) of 18 evaluable CD4-guided arm patients achieved viral suppression after retreatment. Antiretroviral (ARV) side effects were similar in all arms. CD4-guided treatment had a 54% ARV cost savings. CONCLUSIONS: This pilot study suggests that CD4-guided HAART is a well-tolerated and cost-saving treatment strategy for patients with high pre-ARV and pre-STI CD4 counts. Week-on-week-off treatment had a high virologic failure rate and was discontinued. The HIV RNA suppression rate was similar in patients treated with continuous HAART and in those retreated with 12 to 24 weeks of HAART after CD4-guided therapy.

Pharmacokinetics of reduced-dose indinavir/ritonavir 400/100 mg twice daily in HIV-1-infected Thai patients.

OBJECTIVE: To study the pharmacokinetics of indinavir/ ritonavir 400/100 mg twice daily in antiretroviral-naive patients at Srinagarind Hospital in Khon Kaen, Thailand. METHODS: This was a steady-state, open-label pharmacokinetic study of 19 patients. A 12 h pharmacokinetic curve was recorded after an overnight fast. Plasma levels of indinavir and ritonavir were determined by a validated HPLC method. Virological failure was defined according to the most recent US Department of Health and Human Services guidelines as a viral load above 400 copies/ml at week 24. RESULTS: Median baseline values for CD4 and viral load were 13cells/mm3 and 167000 copies/ml, respectively. The median (interquartile ranges) for indinavir AUC, Cmax and Cmin were 18.1 (15.3-23.8) mg/l x h, 4.1 (3.6-4.8) mg/l and 0.17 (0.12-0.30) mg/l, respectively. These values represent 37%, 39% and 24% of the AUC, Cmax and Cmin values found, respectively, for the indinavir/ritonavir 800/100 mg dose in HIV-1-infected Thai patients. Short-term virological response was satisfactory. There were three subjects with an indinavir Cmin. below the target value of 0.10 mg/l, of whom one had virological failure (33%). Among the other 16 subjects with an indinavir Cmin above 0.10 mg/l, there was also one virological failure (6%) (P=0.30). CONCLUSIONS: Indinavir exposure in this reduced-dose regimen of 400 mg with 100 mg ritonavir twice daily was more than dose-proportionally lower than previously observed with the indinavir/ritonavir 800/100 mg twice daily regimen. Therapeutic Cmin levels of indinavir were achieved in >80% of the subjects and short-term virological response was satisfactory in this cohort of patients starting highly active antiretroviral therapy at an advanced disease stage with high baseline viral loads.

A prospective, randomized trial of structured treatment interruption for patients with chronic HIV type 1 infection.

BACKGROUND: Structured treatment interruption was evaluated in 74 patients who had been pretreated with antiretrovirals, consisting of 2 nucleoside reverse-transcriptase inhibitors (NRTIs) for 1 year followed by 3 years of highly active antiretroviral therapy containing a protease inhibitor. METHODS: Patients with a CD4 cell count of > or =350 cells/microL and a plasma viral load of <50 copies/mL were randomized to 3 therapy arms: (1) continuous therapy, (2) CD4 cell count-guided theory, and (3) week-on/week-off (WOWO) therapy. The efficacy and safety of structured treatment interruption and antiretroviral use were evaluated in human immunodeficiency type 1 (HIV-1)-infected patients. The study end points were percentage of patients who developed AIDS or who died and a CD4 cell count of > or =350 cells/microL. Intergroup differences were analyzed using analysis of variance and Kruskal-Wallis tests. RESULTS: Baseline characteristics at the start of the structured treatment interruption were similar. At week 48, no patient had died, and 1 patient in the WOWO group had an AIDS-defining condition. The proportions of patients with a CD4 cell count of > or =350 cells/microL were 100%, 87%, and 96% in treatment arms 1, 2, and 3, respectively. The percentages of weeks of antiretroviral use were 100%, 41.1%, and 69.8% in arms 1, 2, and 3, respectively. The adverse events were not significantly different among arms (P=.27). Thirty-one percent of patients in the WOWO group experienced virological failure. CONCLUSION: WOWO therapy maintained a CD4 cell count of > or =350 cells/microL in almost all patients but was associated with high virological failures rates (possibly resulting from previous dual-NRTI therapy), indicating that this strategy is less useful. Receipt of CD4 cell count-guided therapy resulted in comparable clinical outcomes to continuous therapy and may save antiretroviral-associated costs, but this needs to be confirmed by a larger trial.

Resistance to dual nucleoside reverse-transcriptase inhibitors in children infected with HIV clade A/E.

The prevalence of nucleoside reverse-transcriptase inhibitor (NRTI) mutations was determined among 95 human immunodeficiency virus-infected Thai children who were treated with dual nucleoside reverse-transcriptase inhibitors. Almost all children had resistance to at least 1 NRTI, and approximately half of the children had resistance to multiple NRTIs. Cross-resistance to stavudine and azidothymidine was universal.

Nevirapine plasma concentrations and concomitant use of rifampin in patients coinfected with HIV-1 and tuberculosis.

OBJECTIVES: In countries with high numbers of HIV/tuberculosis coinfection nevirapine and rifampin are used extensively. However, limited data are available about whether or not nevirapine and rifampin can be safely coadministered without the plasma concentration of nevirapine falling below therapeutic levels. METHODS: Blood samples for determination of nevirapine plasma concentrations were collected from patients using nevirapine 200 mg twice daily with or without concomitant rifampin. Bivariate and multivariate linear regression models were used to investigate factors possibly related to nevirapine concentrations. RESULTS: We received 74 blood samples from patients using nevirapine plus rifampin, and collected blood samples from an equal number of controls using nevirapine only. Groups were similar for age, gender, weight, height and body mass index (BMI). In the rifampin group the mean nevirapine concentration was 5.47 +/- 2.66 mg/l, whereas in the control group the mean nevirapine concentration was 8.72 +/- 3.98 mg/l. In the rifampin group seven nevirapine trough concentrations were low (< 3.1 mg/l), while in the control group two patients had low nevirapine trough concentrations (P = 0.164). In the multivariate linear regression analysis, corrected for time after drug intake, the use of rifampin was significantly (P < 0.001) associated with lower nevirapine plasma concentrations, whereas higher BMI reached borderline significance (P = 0.065). CONCLUSION: Although nevirapine plasma concentrations were 3.3 mg/l lower when co-administered with rifampin, still more than 86% of these patients had nevirapine plasma concentrations > 3.1 mg/l. Our results suggest that from a pharmacological point of view the majority of Thai coinfected patients, who have low BMIs, reach nevirapine plasma concentrations that are adequate for treatment of HIV. However this can only be undertaken if nevirapine plasma concentration monitoring is available and can be closely followed.

Impact of viral hepatitis co-infection on response to antiretroviral therapy and HIV disease progression in the HIV-NAT cohort.

OBJECTIVE: To examine the impact of viral hepatitis co-infection on HIV disease outcomes following commencement of combination antiretroviral therapy in a developing country setting. METHODS: HIV RNA suppression, CD4 cell count recovery, and HIV disease progression were examined within a cohort of Thai HIV-infected patients enrolled in eight HIV-NAT randomized controlled trials of antiretroviral therapy (n = 692). Hepatitis B virus (HBV) and hepatitis C virus (HCV) testing was performed on stored serum. RESULTS: Mean age was 32.3 years, 52% were male, 11% had CDC category C HIV disease at baseline, and 22% had received prior antiretroviral therapy. Prevalence of HBV, HCV and HBV/HCV co-infection was 8.7, 7.2 and 0.4%, respectively. Median HIV RNA reductions (log10 copies/ml) were approximately 1.5 for HIV, HIV-HBV, HIV-HCV subgroups from week 4 up to week 48. Mean increases in CD4 cell count were significantly lower among HIV-HBV and HIV-HCV subgroups at week 4 (HIV, 62 x 10(6) cells/l; HIV-HBV, 29 x 10(6) cells/l; HIV-HCV, 33 x 10(6) cells/l), however, by week 48 CD4 cell increases were similar (HIV, 115 x 10(6) cells/l; HIV-HBV, 113 x 10(6) cells/l; HIV-HCV, 97 x 10(6) cells/l). Cox regression analyses showed that HIV-HBV or HIV-HCV co-infection were not associated with a CD4 cell count increase of 100 x 10(6) cells/l over 48 weeks. Estimated progression to AIDS event or death at week 48 was 3.3% (95% confidence interval, 2.0-5.1%) for HIV, 6.7% (2.5-14.6%) for HIV-HBV, and 8.0% (2.2-20.5%) for HIV-HCV subgroups (P > 0.05). CONCLUSIONS: An early delayed CD4 count recovery among HIV/viral hepatitis co-infected patients was not sustained, and was not associated with increased HIV disease progression.

Risk of severe hepatotoxicity associated with antiretroviral therapy in the HIV-NAT Cohort, Thailand, 1996-2001.

OBJECTIVE: To examine rates and predictors of severe hepatotoxicity with combination antiretroviral therapy in a developing country setting: the eight HIV-NAT randomized controlled trials in Thailand. METHODS: All patients (n = 692) received at least two nucleoside reverse transcriptase inhibitors; 215 also received a non-nucleoside reverse transcriptase inhibitor (NNRTI) and 135 also received a protease inhibitor. Severe hepatotoxicity was defined as an increase in alanine aminotransferase (ALT) level to five times the upper limit of normal and an increase of at least 100 U/l from baseline. Liver function tests were available at baseline and weeks 4, 8, 12, 24, 36 and 48. Hepatitis B virus (HBV) and hepatitis C virus (HCV) testing was performed on stored serum. RESULTS: Mean age was 32.3 years; 52% were male, 11% had Centers for Disease Control and Prevention category C HIV disease at baseline, and 22% had received prior antiretroviral therapy. Prevalence of HBV, HCV and HBV/HCV coinfection was 8.7%, 7.2%, and 0.4%, respectively. Incidence of severe hepatotoxicity was 6.1/100 person-years [95% confidence interval (CI), 4.3-8.3/100]. In multivariate analysis, predictors of severe hepatotoxicity were HBV or HCV coinfection, and NNRTI-containing therapy. Incidence of severe hepatotoxicity was particularly high among patients receiving nevaripine (18.5/100 person-years; 95% CI, 11.6-27.8) and nevirapine/efavirenz (44.4/100 person-years; 95% CI, 12.1-113.7). CONCLUSIONS: Incidence and risk factors for severe hepatotoxicity appear similar among these Thai patients to those in other racial groups. Development of standardized antiretroviral therapy regimens for developing country settings should consider potential toxicity and capabilities for monitoring of toxicity.