Publications by authors named "Bhavani Perumal Kannabiran"

Background: Antimicrobial peptides are an important component of host defense against Mycobacterium tuberculosis. However, the ability of BCG to induce AMPs as part of its mechanism of action has not been investigated in detail.

Methods: We investigated the impact of Bacillus Calmette-Guerin (BCG) vaccination on circulating plasma levels and TB-antigen stimulated plasma levels of AMPs in a healthy elderly population.

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Article Synopsis
  • The study aimed to examine the prevalence of non-communicable diseases, particularly diabetes, among household contacts of individuals with tuberculosis (TB).
  • A systematic review identified 39 studies, with 14 providing individual participant data and 25 offering aggregated data; the results showed a pooled diabetes prevalence of 8.8% among those tested properly.
  • Findings indicate that diabetes prevalence among household contacts is likely underestimated, highlighting the importance of targeted interventions during TB contact investigations to identify and address these health issues.
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Background: Globally, no trial data are available on head-to-head comparison between 10 mg/kg and 25/35 mg/kg rifampicin in treating pulmonary tuberculosis during study initiation.

Methods: A multicentric, phase IIb randomized trial recruited 333 new culture-positive, drug-sensitive adult patients with pulmonary tuberculosis to compare safety and efficacy of high-dose rifampicin (R25/R35), against conventional dose (R10) given daily for 8 weeks followed by standard doses for 16 weeks. Main outcomes were treatment-emergent grade 3/4 adverse events (AEs) and time-to-culture conversion in liquid media, assessed by division of AIDS system for grading the severity of adverse events division of AIDS criteria and Kaplan-Meier methods.

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  • The study aimed to investigate how metformin affects the plasma levels of tuberculosis drugs (rifampicin, isoniazid, and pyrazinamide) in patients undergoing standard antituberculosis treatment (ATT) and the role of specific gene polymorphisms on drug metabolism.
  • In a phase IIB clinical trial, non-diabetic adults with pulmonary tuberculosis were divided into two groups: one receiving standard ATT and the other receiving ATT plus metformin; pharmacokinetic measurements were taken to assess drug levels.
  • Results indicated that metformin increased the clearance of rifampicin, isoniazid, and pyrazinamide, particularly in patients with certain genetic variants, though it had minimal impact on treatment
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Background: Studies have reported the beneficial effects of Bacillus Calmette Guerin (BCG) vaccination, including non-specific cross-protection against other infectious diseases.

Methods: We investigated the impact of BCG vaccination on the frequencies of B cell subsets as well as total antibody levels in healthy elderly individuals at one month post vaccination. We also compared the above-mentioned parameters in post-vaccinated individuals to unvaccinated controls.

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High-dose rifampicin (HDR) is now undergoing clinical trials to improve the efficacy of anti-tuberculosis treatment (ATT). However, the influence of HDR in the modulation of different cytokines, chemokines/growth factors, microbial translocation markers (MTMs), and acute-phase proteins (APPs) in pulmonary tuberculosis (PTB) is not well known. PTB individuals were separated into three different arms (R10, R25, and R35) based on their rifampicin dosage.

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BCG vaccination is known to induce innate immune memory, which confers protection against heterologous infections. However, the effect of BCG vaccination on the conventional adaptive immune cells subsets is not well characterized. We investigated the impact of BCG vaccination on the frequencies of T cell subsets and common gamma c (γc) cytokines in a group of healthy elderly individuals (age 60-80 years) at one month post vaccination as part of our clinical study to examine the effect of BCG on COVID-19.

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Objective: BCG can improve the response to vaccines directed against viral infections, and also, BCG vaccination reduces all-cause mortality, most likely by protecting against unrelated infections. However, the effect of BCG vaccination on dendritic cell (DC) subsets is not well characterized.

Methods: We investigated the impact of BCG vaccination on the frequencies of DC subsets and type I and III interferons (IFNs) using whole blood and plasma samples in a group of elderly individuals (age 60-80 years) at one-month post-vaccination as part of our clinical study to examine the effect of BCG on COVID-19.

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Pulmonary disease due to Mycobacterium abscessus (Mab) has become an increasing cause of health concern, particularly among individuals infected with nontuberculous mycobacteria. Since Mab is intrinsically resistant to many antibiotics, it is very challenging to treat patients with symptomatic disease. In this case series, we report four patients with symptomatic pulmonary Mab who had prior history of antituberculosis treatment intake and declared cured at the end of treatment.

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Importance: The benefit of daily over thrice-weekly antituberculosis therapy among HIV-positive patients with pulmonary tuberculosis (TB) who are receiving antiretroviral therapy remains unproven.

Objective: To compare the efficacy and safety of daily, part-daily, and intermittent antituberculosis therapy regimens in the treatment of HIV-associated pulmonary TB.

Design, Setting, And Participants: This open-label, randomized clinical trial was conducted by the National Institute for Research in Tuberculosis, south India.

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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.

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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.

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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.

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Background: Nevirapine is an important component of paediatric combination HIV therapy. Adequate drug exposure is necessary in order to achieve long-lasting viral suppression.

Objectives: To study the influence of age, drug dose and formulation type, nutritional status and CYP2B6 516G>T polymorphism on blood concentrations of nevirapine in children treated with generic antiretroviral drugs.

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