Effect of Metformin on systemic chemokine responses during anti-tuberculosis chemotherapy.

BACKGROUND: Metformin (MET), by boosting immunity, has been suggested as a host-adjunctive therapy to anti-tuberculosis treatment (ATT). METHODS: We evaluated whether adding MET to the standard ATT can alter the host chemokine response. We investigated the influence of metformin on the plasma levels of a wide panel of chemokines in a group of active tuberculosis patients before treatment, at 2nd month of ATT and at 6-months of ATT as part of our clinical study to examine the effect of metformin on ATT. RESULTS: Our results demonstrated that addition of metformin resulted in diminished CC (CCL1 and CCL3) and CXC (CXCL-2 and CXCL-10) chemokines in MET arm as compared to non-MET arm at the 2nd month and 6th month of ATT. In addition to this, MET arm showed significantly diminished chemokines in individuals with high bacterial burden and cavitary disease. CONCLUSION: Our current data suggest that metformin alters chemokines responses that could potentially curb excessive inflammation during ATT.

Effectiveness of isoniazid preventive therapy on incidence of tuberculosis among HIV-infected adults in programme setting.

BACKGROUND & OBJECTIVES: As India and other developing countries are scaling up isoniazid preventive therapy (IPT) for people living with HIV (PLHIV) in their national programmes, we studied the feasibility and performance of IPT in terms of treatment adherence, outcome and post-treatment effect when given under programmatic settings. METHODS: A multicentre, prospective pilot study was initiated among adults living with HIV on isoniazid 300 mg with pyridoxine 50 mg after ruling out active tuberculosis (TB). Symptom review and counselling were done monthly during IPT and for six-month post-IPT. The TB incidence rate was calculated and risk factors were identified. RESULTS: Among 4528 adults living with HIV who initiated IPT, 4015 (89%) successfully completed IPT. IPT was terminated in 121 adults (3%) due to grade 2 or above adverse events. Twenty five PLHIVs developed TB while on IPT. The incidence of TB while on IPT was 1.17/100 person-years (p-y) [95% confidence interval (CI) 0.8-1.73] as compared to TB incidence of 2.42/100 p-y (95% CI 1.90-3.10) during the pre-IPT period at these centres (P=0.017). The incidence of TB post-IPT was 0.64/100 p-y (95% CI 0.04-1.12). No single factor was significantly associated with the development of TB. INTERPRETATION & CONCLUSIONS: Under programmatic settings, completion of IPT treatment was high, adverse events minimal with good post-treatment protection. After ruling out TB, IPT should be offered to all PLHIVs, irrespective of their antiretroviral therapy (ART) status. Scaling-up of IPT services including active case finding, periodic counselling on adherence and re-training of ART staff should be prioritized to reduce the TB burden in this community.

Profile of patients with pulmonary non-tuberculous mycobacterial disease mimicking pulmonary tuberculosis.

INTRODUCTION: With the introduction of newer molecular diagnostic tools, an increasing number of Non-tuberculous Mycobacteria (NTM) affecting the respiratory system and mimicking symptoms of pulmonary tuberculosis (PTB) are being identified. They may be misdiagnosed and treated as PTB, often categorized as treatment failures if they do not respond to treatment. This manuscript aims to characterize patients with pulmonary NTM disease. METHODS: Patient characteristics of bacteriologically confirmed pulmonary NTM disease, attending the ICMR-National Institute for Research in Tuberculosis, Chennai were prospectively compiled over a two-year period (2017-2018). RESULTS: A total of 122 patients with recurrent chest symptoms and not responding to anti-tuberculosis treatment were screened for NTM. Thirty-nine cases (26 males and 13 females) of symptomatic pulmonary NTM were diagnosed. The mean (SD) patient age and body mass index were 48.6 ± 11 years and 16.3 ± 3. All male participants were smokers, had at least one episode of previous ATT. Mycobacterium kansasii (48.7%) was the most frequently isolated species followed by Mycobacterium intracellulare (20.5%), Mycobacterium abscessus (7.6%) followed by Mycobacterium avium, Mycobacterium fortuitum, Mycobacterium kyorinense, and Mycobacterium simiae. Infection with multiple NTMs was seen in four patients. Isoniazid resistance was identified in 20 patients. Based on species identified, treatment was initiated as per American Thoracic Society guidelines and continued up to 12 months of culture negativity. CONCLUSIONS: M. kansasii is the commonest pulmonary NTM isolated in Tamilnadu with a higher prevalence in males and elderly. Sensitization of both patients and providers is essential to avoid misdiagnosis and delay in diagnosis of pulmonary NTM disease as pulmonary TB.