Perumal Kannabiran Bhavani

Efficacy and Safety of Once-Daily Nevirapine- or Efavirenz-Based Antiretroviral Therapy in HIV-Associated Tuberculosis: A Randomized Clinical Trial

BACKGROUND Nevirapine (NVP) can be safely and effectively administered once-daily but has not been assessed in human immunodeficiency virus (HIV)-infected patients with tuberculosis (TB). We studied the safety and efficacy of once-daily NVP, compared with efavirenz (EFV; standard therapy); both drugs were administered in combination with 2 nucleoside reverse-transcriptase inhibitors. METHODS An open-label, noninferiority, randomized controlled clinical trial was conducted at 3 sites in southern India. HIV-infected patients with TB were treated with a standard short-course anti-TB regimen (2EHRZ(3)/4RH(3); [2 months of Ethambutol, Isoniazid, Rifampicin, Pyrazinamide / 4 months of Isoniazid and Rifampicin] thrice weekly) and randomized to receive once-daily EFV at a dose of 600 mg or NVP at a dose of 400 mg (after 14 days of 200 mg administered once daily) with didanosine 250/400 mg and lamivudine 300 mg after 2 months. Sputum smears and mycobacterial cultures were performed every month. CD4+ cell count, viral load, and liver function test results were monitored periodically. Primary outcome was a composite of death, virological failure, default, or serious adverse event (SAE) at 24 weeks. Both intent-to-treat and per protocol analyses were done, and planned interim analyses were performed. RESULTS A total of 116 patients (75% [87 patients] of whom had pulmonary TB), with a mean age of 36 years, a median CD4+ cell count of 84 cells/mm(3), and a median viral load of 310 000 copies/mL, were randomized. At 24 weeks, 50 of 59 patients in the EFV group and 37 of 57 patients in the NVP group had virological suppression (P = .024). There were no deaths, 1 SAE, and 5 treatment failures in the EFV arm, compared with 5 deaths, 2 SAEs, and 10 treatment failures in the NVP arm. The trial was halted by the data and safety monitoring board at the second interim analysis. Favorable TB treatment outcomes were observed in 93% of the patients in the EFV arm and 84% of the patients in the NVP arm (P = .058). CONCLUSIONS Compared with a regimen of didanosine, lamivudine, and EFV, a regimen of once-daily didanosine, lamivudine, and NVP was inferior and was associated with more frequent virologic failure and death. Clinical Trials Registration. NCT00332306.

Age, nutritional status and INH acetylator status affect pharmacokinetics of anti-tuberculosis drugs in children

SETTING The currently recommended dosages of rifampicin (RMP), isoniazid (INH), pyrazinamide (PZA) and ethambutol in children are extrapolated from adult pharmacokinetic studies, and have not been adequately evaluated in children. OBJECTIVE To describe the pharmacokinetics of RMP, INH and PZA given thrice weekly in children with tuberculosis (TB), and to relate pharmacokinetics to treatment outcomes. METHODS Eighty-four human immunodeficiency virus negative children with TB aged 1-12 years in Chennai and Madurai, India, were recruited. Phenotypic INH acetylator status was determined. Nutritional status was assessed using Z scores. During the intensive phase of anti-tuberculosis treatment, a complete pharmacokinetic study was performed after directly observed administration of drugs. At 2 and 6 months, drug levels were measured 2 h post-dose. Drug concentrations were measured using high performance liquid chromatography and pharmacokinetic variables were calculated. Multivariable regression analysis was performed to explore factors impacting drug levels and treatment outcomes. RESULTS AND CONCLUSIONS Children aged <3 years had significantly lower RMP, INH and PZA concentrations than older children, and 90% of all children had sub-therapeutic RMP Cmax (<8 μg/ml). Age, nutritional status and INH acetylator status influenced drug levels. Peak RMP and INH concentrations were important determinants of treatment outcome. Recommendations for anti-tuberculosis treatment in children should take these factors into consideration.

Prevalence of Underweight, Stunting, and Wasting among Children Infected with Human Immunodeficiency Virus in South India

Background. Growth failure is a common feature of children with human immunodeficiency virus (HIV) infection. Malnutrition increases mortality and may impair the response to antiretroviral treatment. Objective. Our objective was to describe the prevalence of stunting, underweight, and wasting in HIV-infected children in south India and to assess the utility of these parameters in predicting immune status. Methodology. In this cross-sectional study, anthropometric measurements and CD4 counts were performed on 231 HIV-infected children. Z scores for height for age, weight for age, and weight for height were correlated with CD4 cell counts and receiver operating characteristic curves plotted. Results. Prevalence of underweight was 63%, stunting 58%, and wasting 16%, respectively. 33–45% of children were moderately or severely malnourished even at CD4 >25%; sensitivity and specificity of stunting or underweight to predict HIV disease severity was low. Conclusions. Undernutrition and stunting are common among HIV-infected children at all stages of the disease in India. Early and aggressive nutritional intervention is required, if long-term outcomes are to be improved.

Pharmacokinetics of First-Line Antituberculosis Drugs in HIV-Infected Children with Tuberculosis Treated with Intermittent Regimens in India

ABSTRACT The objective of this report was to study the pharmacokinetics of rifampin (RMP), isoniazid (INH), and pyrazinamide (PZA) in HIV-infected children with tuberculosis (TB) treated with a thrice-weekly anti-TB regimen in the government program in India. Seventy-seven HIV-infected children with TB aged 1 to 15 years from six hospitals in India were recruited. During the intensive phase of TB treatment with directly observed administration of the drugs, a complete pharmacokinetic study was performed. Drug concentrations were measured by high-performance liquid chromatography. A multivariable regression analysis was done to explore the factors impacting drug levels and treatment outcomes. The proportions of children with subnormal peak concentrations (Cmax) of RMP, INH, and PZA were 97%, 28%, and 33%, respectively. Children less than 5 years old had a lower median Cmax and lower exposure (area under the time-concentration curve from 0 to 8 h [AUC0–8]) of INH (Cmax, 2.5 versus 5.1 μg/ml, respectively [P = 0.016]; AUC0–8, 11.1 versus 22.0 μg/ml · h, respectively [P = 0.047[) and PZA (Cmax, 34.1 versus 42.3 μg/ml, respectively [P = 0.055]; AUC0–8, 177.9 versus 221.7 μg/ml · h, respectively [P = 0.05]) than those more than 5 years old. In children with unfavorable versus favorable outcomes, the median Cmax of RMP (1.0 versus 2.8 μg/ml, respectively; P = 0.002) and PZA (31.9 versus 44.4 μg/ml, respectively; P = 0.045) were significantly lower. Among all factors studied, the PZA Cmax influenced TB treatment outcome (P = 0.011; adjusted odds ratio, 1.094; 95% confidence interval, 1.021 to 1.173). A high proportion of children with HIV and TB had a subnormal RMP Cmax. The PZA Cmax significantly influenced treatment outcome. These findings have important clinical implications and emphasize that drug doses in HIV-infected children with TB have to be optimized.

Evaluation of a diagnostic algorithm for sputum smear-negative pulmonary tuberculosis in HIV-infected adults.

Background:The Revised National TB Control Program bases diagnosis of tuberculosis (TB) on sputum smear examination and response to a course of antibiotics, whereas World Health Organization recommends early chest radiography [chest x-ray (CXR)] for HIV-infected symptomatic patients. We evaluated the utility of initial CXR in the diagnostic algorithm for symptomatic HIV-infected patients with negative sputum smears. Methods:HIV-infected ambulatory patients with cough or fever of ≥2 weeks and 3 sputum smears negative for acid-fast bacilli were enrolled in Chennai and Pune, India, between 2007 and 2009. After a CXR and 2 sputum cultures, a course of broad-spectrum antibiotics was given and patients were reviewed after 14 days. Sensitivity, specificity, positive and negative predictive values of symptoms, CXR, and various combinations for diagnosing pulmonary tuberculosis (PTB) were determined, using sputum culture as gold standard. Results:Five hundred four patients (330 males; mean age: 35 years; median CD4: 175 cells per cubic millimeter) were enrolled. CXR had a sensitivity and specificity of 72% and 57%, respectively, with positive predictive value (PPV) of 21% and negative predictive value (NPV) of 93% to diagnose PTB. TB culture was positive in 49 of 235 patients (21%) with an abnormal initial CXR and 19 of 269 patients (7%) with a normal CXR (P < 0.001). Sensitivity and specificity of cough ≥2 weeks for predicting PTB was 97% and 6%, with PPV and NPV of 14% and 94%, respectively. Conclusions:Although moderately sensitive, basing a diagnosis of TB on initial CXR leads to overdiagnosis. An absence of weight loss had a high NPV, whereas none of the combinations had a good PPV. A rapid and accurate diagnostic test is required for HIV-infected chest symptomatic.

Early changes in hepatic function among HIV–tuberculosis patients treated with nevirapine or efavirenz along with rifampin-based anti-tuberculosis therapy

OBJECTIVES To describe the longitudinal changes in hepatic function among HIV-infected tuberculosis (TB) patients receiving once-daily nevirapine (NVP)- or efavirenz (EFV)-based antiretroviral treatment (ART) along with rifampin-containing anti-TB treatment. METHODS This was a nested study within a randomized clinical trial, taking place between May 2006 and June 2008 at the National Institute for Research in Tuberculosis, Chennai, India. Antiretroviral-naïve HIV-infected TB patients were initiated on an intermittent short-course regimen and randomized to receive didanosine and lamivudine with either NVP (400 mg) or EFV (600 mg) once-daily. Blood was analyzed for alanine aminotransferase (ALT), aspartate aminotransferase (AST), serum alkaline phosphatase (SAP), and bilirubin at baseline, at ART initiation, fortnightly after ART initiation until 2 months, then monthly until 6 months and 6-monthly thereafter. RESULTS Of the 168 patients included (79% men, median CD4 count 93 cells/mm3, median viral load 242,000 copies/ml), 104 were on EFV-based ART and 64 on NVP-based ART. There was a small but statistically significant elevation in ALT and SAP at 2 weeks and AST at 6 weeks after ART initiation. The proportion of patients with rate-limiting toxicity of liver enzymes was small. None had treatment terminated because of hepatotoxicity. CONCLUSION Hepatotoxicity is not a major concern when HIV-infected TB patients, with normal baseline liver function initiate treatment for both infections simultaneously.

Defective dendritic cell response to Toll-like receptor 7/8 agonists in perinatally HIV-infected children

Understanding the defects in innate immunity associated with perinatal HIV infection is a prerequisite for effective antiretroviral treatment. We therefore compared the innate immune response [dendritic cell (DC) phenotype and function] in peripheral blood by flow cytometry at baseline and 12 months in HIV-infected children to determine the defect associated with perinatal HIV infection. As compared with controls, patients had decreased numbers of total DCs including plasmacytoid (p)DCs and myeloid (m)DCs and impaired function based on induction of maturation markers (CD83, CD80, CCR7) and cytokines tumor necrosis factor-α and interferon-α (exclusive to pDC) upon stimulation with the TLR7/8 agonist Resiquimod. These abnormalities were evident in all three CD4 immune categories and persisted over 12 months; pDC function worsened in HIV+ children without treatment and improved slightly in those on highly active antiretroviral therapy (HAART). In conclusion, a majority of perinatally HIV-infected older children without HAART remain clinically stable in the short term, but have demonstrable immunologic abnormalities indicative of defects in the innate immune system. Children initiated on HAART showed improvement in CD4 counts but did not show improvement in DC function over the short term.

Suboptimal Antituberculosis Drug Concentrations and Outcomes in Small and HIV-Coinfected Children in India: Recommendations for Dose Modifications

This work aimed to evaluate the once‐daily antituberculosis treatment as recommended by the new Indian pediatric guidelines. Isoniazid, rifampin, and pyrazinamide concentration–time profiles and treatment outcome were obtained from 161 Indian children with drug‐sensitive tuberculosis undergoing thrice‐weekly dosing as per previous Indian pediatric guidelines. The exposure–response relationships were established using a population pharmacokinetic‐pharmacodynamic approach. Rifampin exposure was identified as the unique predictor of treatment outcome. Consequently, children with low body weight (4–7 kg) and/or HIV infection, who displayed the lowest rifampin exposure, were associated with the highest probability of unfavorable treatment (therapy failure, death) outcome (Punfavorable). Model‐based simulation of optimized (Punfavorable ≤ 5%) rifampin once‐daily doses were suggested per treatment weight band and HIV coinfection status (33% and 190% dose increase, respectively, from the new Indian guidelines). The established dose‐exposure–response relationship could be pivotal in the development of future pediatric tuberculosis treatment guidelines.

High Prevalence of Lipid Abnormalities and Insulin Resistance Among Antiretroviral Naïve HIV-Infected Children in India

Background: As large numbers of children are accessing antiretroviral therapy (ART) in India, we evaluated the dietary intake, growth pattern and risk of metabolic complications like dyslipidemia and insulin resistance among ART-naïve HIV-infected children (CLHIV). Methods: CLHIV 2–12 years of age, at the time of initiating ART in Chennai and Bangalore, were assessed for their dietary intake, anthropometry, blood CD4 cell count, HIV-1 viral load, fasting serum lipids, glucose and insulin. Homeostatic model assessment-insulin resistance was derived. Results: Three hundred and ninety CLHIV (mean age [SD]: 8 [3] yrs; median viral load: 141,000 [25,876–436,000] copies/mL) were started on non-nucleoside reverse transcriptase inhibitor-based ART. Perinatal infection was documented among 97%. Sixty percent of children were in stage 3 or 4 of World Health Organization clinical staging of HIV/AIDS. Food insecurity was seen in 40% of households. A total of 204 children (52.4%) were stunted and 224 (57.6%) were underweight. Stunting seemed to be more prevalent with increasing age (0–4 years: 48%; >9 years: 60%). Mean intakes of calories, iron, folate and calcium were significantly less than recommended dietary allowances across all age groups. Dyslipidemia, in terms of any abnormal triglycerides or total cholesterol or low-density lipoprotein cholesterol (excluding high-density lipoprotein cholesterol), was seen in approximately 40% of children; insulin resistance in 17%; and C-reactive protein in risk range of metabolic syndrome in 24% of children. Conclusions: In the background of high food insecurity and malnutrition, cardiometabolic abnormalities were seen in 20%–35% of ART-naïve CLHIV in India emphasizing close monitoring of these children for long-term cardiovascular morbidities after initiation of ART.