The sound of silent RNA in tuberculosis and the lncRNA role on infection

Tuberculosis (TB) is one of the leading causes of death worldwide, and Diabetes Mellitus is one of the major comorbidities (TB/DM) associated with the disease. A total of 103 differentially expressed ncRNAs have been identified in the TB and TB/DM comparisons. A machine learning algorithm was employed to identify the most informative lncRNAs: ADM-DT, LINC02009, LINC02471, SOX2-OT, and GK-AS1. These lncRNAs presented substantial accuracy in classifying TB from HC (AUCs >0.85) and TB/DM from HC (AUCs >0.90) in the other three countries. Genes with significant correlations with the five lncRNAs enriched common pathways in Brazil and India for both TB and TB/DM. This suggests that lncRNAs play an important role in the regulation of genes related to the TB immune response.

Early Microbiologic Markers of Pulmonary Tuberculosis Treatment Outcomes

Rationale: Earlier biomarkers of pulmonary tuberculosis (PTB) treatment outcomes are critical to monitor shortened anti-TB treatment (ATT). Objectives: To identify early microbiologic markers of unfavorable TB treatment outcomes. Methods: We performed a subanalysis of 2 prospective TB cohort studies conducted from 2013 to 2019 in India. We included participants aged ⩾18 years who initiated 6-month ATT for clinically or microbiologically diagnosed drug-sensitive PTB and completed at least one follow-up visit. Sputum specimens were subjected to a baseline Xpert Mycobacterium tuberculosis/rifampin (MTB/RIF) assay, acid-fast bacilli (AFB) microscopy and liquid and solid cultures, and serial AFB microscopy and liquid and solid cultures at weeks 2, 4, and 8. Poisson regression was used to assess the impact of available microbiologic markers (test positivity, smear grade, time to detection, and time to conversion) on a composite outcome of failure, recurrence, or death by 18 months after the end of treatment. Models were adjusted for age, sex, nutritional status, diabetes, smoking, alcohol consumption, and regimen type. Results: Among 1,098 eligible cases, there were 251 (22%) adverse TB treatment outcomes: 127 (51%) treatment failures, 73 (29%) recurrences, and 51 (20%) deaths. The primary outcome was independently associated with the Xpert MTB/RIF assay (medium-positive adjusted incidence rate ratio [aIRR], 1.91; 95% confidence interval [CI], 1.07-3.40; high-positive aIRR, 2.51; 95% CI, 1.41-4.46), positive AFB smear (aIRR, 1.48; 95% CI, 1.06-2.06), and positive liquid culture (aIRR, 1.98; 95% CI, 1.21-3.23) at baseline; Week 2 positive liquid culture (aIRR, 1.47; 95% CI, 1.04-2.09); and Week 8 positive AFB smear (aIRR, 1.63; 95% CI, 1.06-2.50) and positive liquid culture (aIRR, 1.54; 95% CI, 1.07-2.22). There was no evidence of Mycobacterium tuberculosis growth in the Mycobacterium Growth Indicator Tube at Week 4 conferring a higher risk of adverse outcomes (aIRR, 1.25; 95% CI, 0.89-1.75). Conclusions: Our analysis identifies Week 2 respiratory mycobacterial culture as the earliest microbiologic marker of unfavorable PTB treatment outcomes.

A multi-center, prospective cohort study of whole blood gene expression in the tuberculosis-diabetes interaction

Diabetes mellitus (DM) increases tuberculosis (TB) severity. We compared blood gene expression in adults with pulmonary TB, with or without diabetes mellitus (DM) from sites in Brazil and India. RNA sequencing (RNAseq) performed at baseline and during TB treatment. Publicly available baseline RNAseq data from South Africa and Romania reported by the TANDEM Consortium were also analyzed. Across the sites, differentially expressed genes varied for each condition (DM, TB, and TBDM) and no pattern classified any one group across all sites. A concise signature of TB disease was identified but this was expressed equally in TB and TBDM. Pathway enrichment analysis failed to distinguish TB from TBDM, although there was a trend for greater neutrophil and innate immune pathway activation in TBDM participants. Pathways associated with insulin resistance, metabolic dysfunction, diabetic complications, and chromosomal instability were positively correlated with glycohemoglobin. The immune response to pulmonary TB as reflected by whole blood gene expression is substantially similar with or without comorbid DM. Gene expression pathways associated with the microvascular and macrovascular complications of DM are upregulated during TB, supporting a syndemic interaction between these coprevalent diseases.

Impact of Undernutrition on Tuberculosis Treatment Outcomes in India: A Multicenter, Prospective, Cohort Analysis

BACKGROUND

Undernutrition is the leading risk factor for tuberculosis (TB) globally. Its impact on treatment outcomes is poorly defined.

METHODS

We conducted a prospective cohort analysis of adults with drug-sensitive pulmonary TB at 5 sites from 2015-2019. Using multivariable Poisson regression, we assessed associations between unfavorable outcomes and nutritional status based on body mass index (BMI) nutritional status at treatment initiation, BMI prior to TB disease, stunting, and stagnant or declining BMI after 2 months of TB treatment. Unfavorable outcome was defined as a composite of treatment failure, death, or relapse within 6 months of treatment completion.

RESULTS

Severe undernutrition (BMI <16 kg/m2) at treatment initiation and severe undernutrition before the onset of TB disease were both associated with unfavorable outcomes (adjusted incidence rate ratio [aIRR], 2.05; 95% confidence interval [CI], 1.42-2.91 and aIRR, 2.20; 95% CI, 1.16-3.94, respectively). Additionally, lack of BMI increase after treatment initiation was associated with increased unfavorable outcomes (aIRR, 1.81; 95% CI, 1.27-2.61). Severe stunting (height-for-age z score <-3) was associated with unfavorable outcomes (aIRR, 1.52; 95% CI, 1.00-2.24). Severe undernutrition at treatment initiation and lack of BMI increase during treatment were associated with a 4- and 5-fold higher rate of death, respectively.

CONCLUSIONS

Premorbid undernutrition, undernutrition at treatment initiation, lack of BMI increase after intensive therapy, and severe stunting are associated with unfavorable TB treatment outcomes. These data highlight the need to address this widely prevalent TB comorbidity. Nutritional assessment should be integrated into standard TB care.

Previous tuberculosis disease as a risk factor for chronic obstructive pulmonary disease: a cross-sectional analysis of multicountry, population-based studies

Background

Risk factors for COPD in high-income settings are well understood; however, less attention has been paid to contributors of COPD in low-income and middle-income countries (LMICs) such as pulmonary tuberculosis. We sought to study the association between previous tuberculosis disease and COPD by using pooled population-based cross-sectional data in 13 geographically diverse, low-resource settings.

Methods

We pooled six cohorts in 13 different LMIC settings, 6 countries and 3 continents to study the relationship between self-reported previous tuberculosis disease and lung function outcomes including COPD (defined as a postbronchodilator forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) below the lower limit of normal). Multivariable regressions with random effects were used to examine the association between previous tuberculosis disease and lung function outcomes.

Results

We analysed data for 12 396 participants (median age 54.0 years, 51.5% male); 332 (2.7%) of the participants had previous tuberculosis disease. Overall prevalence of COPD was 8.8% (range 1.7%–15.5% across sites). COPD was four times more common among those with previous tuberculosis disease (25.7% vs 8.3% without previous tuberculosis disease, p<0.001). The adjusted odds of having COPD was 3.78 times higher (95% CI 2.87 to 4.98) for participants with previous tuberculosis disease than those without a history of tuberculosis disease. The attributable fraction of COPD due to previous tuberculosis disease in the study sample was 6.9% (95% CI 4.8% to 9.6%). Participants with previous tuberculosis disease also had lower prebronchodilator Z-scores for FEV1(−0.70, 95% CI −0.84 to −0.55), FVC (−0.44, 95% CI −0.59 to −0.29) and the FEV1:FVC ratio (−0.63, 95% CI −0.76 to −0.51) when compared with those without previous tuberculosis disease.

Conclusions

Previous tuberculosis disease is a significant and under-recognised risk factor for COPD and poor lung function in LMICs. Better tuberculosis control will also likely reduce the global burden of COPD.

Tuberculosis (TB) Aftermath: study protocol for a hybrid type I effectiveness-implementation non-inferiority randomized trial in India comparing two active case finding (ACF) strategies among individuals treated for TB and their household contacts

BACKGROUND

Approximately 7% of all reported tuberculosis (TB) cases each year are recurrent, occurring among people who have had TB in the recent or distant past. TB recurrence is particularly common in India, which has the largest TB burden worldwide. Although patients recently treated for TB are at high risk of developing TB again, evidence around effective active case finding (ACF) strategies in this population is scarce. We will conduct a hybrid type I effectiveness-implementation non-inferiority randomized trial to compare the effectiveness, cost-effectiveness, and feasibility of two ACF strategies among individuals who have completed TB treatment and their household contacts (HHCs).

METHODS

We will enroll 1076 adults (≥ 18 years) who have completed TB treatment at a public TB unit (TU) in Pune, India, along with their HHCs (averaging two per patient, n = 2152). Participants will undergo symptom-based ACF by existing healthcare workers (HCWs) at 6-month intervals and will be randomized to either home-based ACF (HACF) or telephonic ACF (TACF). Symptomatic participants will undergo microbiologic testing through the program. Asymptomatic HHCs will be referred for TB preventive treatment (TPT) per national guidelines. The primary outcome is rate per 100 person-years of people diagnosed with new or recurrent TB by study arm, within 12 months following treatment completion. The secondary outcome is proportion of HHCs < 6 years, by study arm, initiated on TPT after ruling out TB disease. Study staff will collect socio-demographic and clinical data to identify risk factors for TB recurrence and will measure post-TB lung impairment. In both arms, an 18-month "mop-up" visit will be conducted to ascertain outcomes. We will use the RE-AIM framework to characterize implementation processes and explore acceptability through in-depth interviews with index patients, HHCs and HCWs (n = 100). Cost-effectiveness will be assessed by calculating the incremental cost per TB case detected within 12 months and projected for disability-adjusted life years averted based on modeled estimates of morbidity, mortality, and time with infectious TB.

DISCUSSION

This novel trial will guide India's scale-up of post-treatment ACF and provide an evidence base for designing strategies to detect recurrent and new TB in other high burden settings.

TRIAL REGISTRATION

NCT04333485 , registered April 3, 2020. CTRI/2020/05/025059 [Clinical Trials Registry of India], registered May 6 2020.

Host lipidome and tuberculosis treatment failure

INTRODUCTION

Host lipids play important roles in tuberculosis (TB) pathogenesis. Whether host lipids at TB treatment initiation (baseline) affect subsequent treatment outcomes has not been well characterised. We used unbiased lipidomics to study the prospective association of host lipids with TB treatment failure.

METHODS

A case-control study (n=192), nested within a prospective cohort study, was used to investigate the association of baseline plasma lipids with TB treatment failure among adults with pulmonary TB. Cases (n=46) were defined as TB treatment failure, while controls (n=146) were those without failure. Complex lipids and inflammatory lipid mediators were measured using liquid chromatography mass spectrometry techniques. Adjusted least-square regression was used to assess differences in groups. In addition, machine learning identified lipids with highest area under the curve (AUC) to classify cases and controls.

RESULTS

Baseline levels of 32 lipids differed between controls and those with treatment failure after false discovery rate adjustment. Treatment failure was associated with lower baseline levels of cholesteryl esters and oxylipin, and higher baseline levels of ceramides and triglycerides compared to controls. Two cholesteryl ester lipids combined in a unique classifier model provided an AUC of 0.79 (95% CI 0.65-0.93) in the test dataset for prediction of TB treatment failure.

CONCLUSIONS

We identified lipids, some with known roles in TB pathogenesis, associated with TB treatment failure. In addition, a lipid signature with prognostic accuracy for TB treatment failure was identified. These lipids could be potential targets for risk-stratification, adjunct therapy and treatment monitoring.

Increased Moxifloxacin Dosing Among Patients With Multidrug-Resistant Tuberculosis With Low-Level Resistance to Moxifloxacin Did Not Improve Treatment Outcomes in a Tertiary Care Center in Mumbai, India

Background

Mycobacterium tuberculosis (Mtb) strains resistant to isoniazid and rifampin (multidrug-resistant tuberculosis [MDR-TB]) are increasingly reported worldwide, requiring renewed focus on the nuances of drug resistance. Patients with low-level moxifloxacin resistance may benefit from higher doses, but limited clinical data on this strategy are available.

Methods

We conducted a 5-year observational cohort study of MDR-TB patients at a tertiary care center in India. Participants with Mtb isolates resistant to isoniazid, rifampin, and moxifloxacin (at the 0.5 µg/mL threshold) were analyzed according to receipt of high-dose moxifloxacin (600 mg daily) as part of a susceptibility-guided treatment regimen. Univariable and multivariable Cox proportional hazard models assessed the relationship between high-dose moxifloxacin and unfavorable treatment outcomes.

Results

Of 354 participants with MDR-TB resistant to moxifloxacin, 291 (82.2%) received high-dose moxifloxacin. The majority experienced good treatment outcomes (200 [56.5%]), which was similar between groups (56.7% vs 54.0%, P = .74). Unfavorable outcomes were associated with greater extent of radiographic disease, lower initial body mass index, and concurrent treatment with fewer drugs with confirmed phenotypic susceptibility. Treatment with high-dose moxifloxacin was not associated with improved outcomes in either unadjusted (hazard ratio [HR], 1.2 [95% confidence interval {CI}, .6–2.4]) or adjusted (HR, 0.8 [95% CI, .5–1.4]) models but was associated with joint pain (HR, 3.2 [95% CI, 1.2–8.8]).

Conclusions

In a large observational cohort, adding high-dose (600 mg) moxifloxacin to a drug susceptibility test–based treatment regimen for MDR-TB was associated with increased treatment-associated side effects without improving overall outcomes and should be avoided for empiric treatment of moxifloxacin-resistant MDR-TB.

Previous tuberculosis disease as a risk factor for chronic obstructive pulmonary disease: a cross-sectional analysis of multicountry, population-based studies

BACKGROUND

Risk factors for COPD in high-income settings are well understood; however, less attention has been paid to contributors of COPD in low-income and middle-income countries (LMICs) such as pulmonary tuberculosis. We sought to study the association between previous tuberculosis disease and COPD by using pooled population-based cross-sectional data in 13 geographically diverse, low-resource settings.

METHODS

We pooled six cohorts in 13 different LMIC settings, 6 countries and 3 continents to study the relationship between self-reported previous tuberculosis disease and lung function outcomes including COPD (defined as a postbronchodilator forced expiratory volume in one second (FEV₁)/forced vital capacity (FVC) below the lower limit of normal). Multivariable regressions with random effects were used to examine the association between previous tuberculosis disease and lung function outcomes.

RESULTS

We analysed data for 12 396 participants (median age 54.0 years, 51.5% male); 332 (2.7%) of the participants had previous tuberculosis disease. Overall prevalence of COPD was 8.8% (range 1.7%-15.5% across sites). COPD was four times more common among those with previous tuberculosis disease (25.7% vs 8.3% without previous tuberculosis disease, p<0.001). The adjusted odds of having COPD was 3.78 times higher (95% CI 2.87 to 4.98) for participants with previous tuberculosis disease than those without a history of tuberculosis disease. The attributable fraction of COPD due to previous tuberculosis disease in the study sample was 6.9% (95% CI 4.8% to 9.6%). Participants with previous tuberculosis disease also had lower prebronchodilator Z-scores for FEV₁ (-0.70, 95% CI -0.84 to -0.55), FVC (-0.44, 95% CI -0.59 to -0.29) and the FEV₁:FVC ratio (-0.63, 95% CI -0.76 to -0.51) when compared with those without previous tuberculosis disease.

CONCLUSIONS

Previous tuberculosis disease is a significant and under-recognised risk factor for COPD and poor lung function in LMICs. Better tuberculosis control will also likely reduce the global burden of COPD.

Baseline IL-6 is a biomarker for unfavorable tuberculosis treatment outcomes: a multi-site discovery and validation study

Background

Biomarkers of unfavorable tuberculosis treatment outcomes are needed to accelerate new drug and regimen development. Whether plasma cytokine levels can predict unfavorable tuberculosis treatment outcomes is unclear.

Methods

We identified and internally validated the association between 20 a-priori selected plasma inflammatory markers and unfavorable treatment outcomes of failure, recurrence and all-cause mortality among adults with drug-sensitive pulmonary tuberculosis in India. We externally validated these findings in two independent cohorts of predominantly diabetic and HIV coinfected tuberculosis patients in India and South Africa, respectively.

Results

Pre-treatment IFN-γ, IL-13 and IL-6 were associated with treatment failure in the discovery analysis. Internal validation confirmed higher pre-treatment IL-6 concentrations among failure cases compared to controls. External validation among predominantly diabetic tuberculosis patients found an association between pre-treatment IL-6 concentrations and subsequent recurrence and death. Similarly, external validation among predominantly HIV coinfected tuberculosis patients found an association between pre-treatment IL-6 concentrations and subsequent treatment failure and death. In a pooled analysis of 363 tuberculosis cases from the Indian and South African validation cohorts, high pre-treatment IL-6 concentrations were associated with higher risk of failure (adjusted odds ratio [aOR]=2.16, 95%CI 1.08-4.33, p=0.02), recurrence (aOR=5.36, 95%CI 2.48-11.57, p<0.001) and death (aOR=4.62, 95%CI 1.95-10.95, p<0.001). Adding baseline IL-6 to a risk-prediction model comprising of low BMI, high smear grade and cavitation improved model performance by 15 percent (C-statistic of 0.66 versus 0.76, p=0.02).

Conclusion

Pre-treatment IL-6 is a biomarker for unfavorable tuberculosis treatment outcomes. Future studies should identify optimal IL-6 concentrations for point-of-care risk prediction.

Unhealthy alcohol use independently associated with unfavorable TB treatment outcomes among Indian men

BACKGROUND: Approximately 10% of incident TB cases worldwide are attributable to alcohol. However, evidence associating alcohol with unfavorable TB treatment outcomes is weak.METHODS: We prospectively evaluated men (≥18 years) with pulmonary TB in India for up to 24 months to investigate the association between alcohol use and treatment outcomes. Unhealthy alcohol use was defined as a score of ≥4 on the Alcohol Use Disorders Identification Test-Concise (AUDIT-C) scale at entry. Unfavorable TB treatment outcomes included failure, recurrence, and all-cause mortality, analyzed as composite and independent endpoints.RESULTS: Among 751 men, we identified unhealthy alcohol use in 302 (40%). Median age was 39 years (IQR 28-50); 415 (55%) were underweight (defined as a body mass index [BMI] <18.5 kg/m²); and 198 (26%) experienced an unfavorable outcome. Unhealthy alcohol use was an independent risk factor for the composite unfavorable outcome (adjusted incidence rate ratio [aIRR] 1.47, 95% CI 1.05-2.06; P = 0.03) and death (aIRR 1.90, 95% CI 1.08-3.34; P = 0.03), specifically. We found significant interaction between AUDIT-C and BMI; underweight men with unhealthy alcohol use had increased risk of unfavorable outcomes (aIRR 2.22, 95% CI 1.44-3.44; P < 0.001) compared to men with BMI ≥18.5 kg/m² and AUDIT-C <4.CONCLUSION: Unhealthy alcohol use was independently associated with unfavorable TB treatment outcomes, highlighting the need for integrating effective alcohol interventions into TB care.

Transcriptomic Profiles of Confirmed Pediatric Tuberculosis Patients and Household Contacts Identifies Active Tuberculosis, Infection, and Treatment Response Among Indian Children

BACKGROUND

Gene expression profiling is emerging as a tool for tuberculosis diagnosis and treatment response monitoring, but limited data specific to Indian children and incident tuberculosis infection (TBI) exist.

METHODS

Sixteen pediatric Indian tuberculosis cases were age- and sex-matched to 32 tuberculosis-exposed controls (13 developed incident TBI without subsequent active tuberculosis). Longitudinal samples were collected for ribonucleic acid sequencing. Differential expression analysis generated gene lists that identify tuberculosis diagnosis and tuberculosis treatment response. Data were compared with published gene lists. Population-specific risk score thresholds were calculated.

RESULTS

Seventy-one genes identified tuberculosis diagnosis and 25 treatment response. Within-group expression was partially explained by age, sex, and incident TBI. Transient changes in gene expression were identified after both infection and treatment. Application of 27 published gene lists to our data found variable performance for tuberculosis diagnosis (sensitivity 0.38-1.00, specificity 0.48-0.93) and treatment response (sensitivity 0.70-0.80, specificity 0.40-0.80). Our gene lists found similarly variable performance when applied to published datasets for diagnosis (sensitivity 0.56-0.85, specificity 0.50-0.85) and treatment response (sensitivity 0.49- 0.86, specificity 0.50-0.84).

CONCLUSIONS

Gene expression profiles among Indian children with confirmed tuberculosis were distinct from adult-derived gene lists, highlighting the importance of including distinct populations in differential gene expression models.

Higher interleukin-6 levels and changes in transforming growth factor-β are associated with lung impairment in pulmonary tuberculosis

Pulmonary tuberculosis (PTB) is associated with granuloma formation, necrosis and cavitation in lung tissue. Lung injury in PTB can persist despite microbiological cure and is associated with COPD independent of smoking exposure [1]. Furthermore, pulmonary sequelae of PTB are an under-recognised cause of respiratory disability and excess mortality [2].

Higher levels of IL-6 and slow-to-resolve TGF-β are associated with lung impairment in treated tuberculosis. These results have important implications for clinical trials of immunomodulatory therapies to prevent tuberculosis-associated lung disease.https://bit.ly/2FQEtsz

Tuberculosis preventive treatment should be considered for all household contacts of pulmonary tuberculosis patients in India

The World Health Organization (WHO) recently changed its guidance for tuberculosis (TB) preventive treatment (TPT) recommending TPT for all pulmonary TB (PTB) exposed household contacts (HHC) to prevent incident TB disease (iTBD), regardless of TB infection (TBI) status. However, this recommendation was conditional as the strength of evidence was not strong. We assessed risk factors for iTBD in recently-exposed adult and pediatric Indian HHC, to determine which HHC subgroups might benefit most from TPT. We prospectively enrolled consenting HHC of adult PTB patients in Pune and Chennai, India. They underwent clinical, microbiologic and radiologic screening for TB disease (TBD) and TBI, at enrollment, 4–6, 12 and 24 months. TBI testing was performed by tuberculin skin test (TST) and Quantiferon®- Gold-in-Tube (QGIT) assay. HHC without baseline TBD were followed for development of iTBI and iTBD. Using mixed-effect Poisson regression, we assessed baseline characteristics including TBI status, and incident TBI (iTBI) using several TST and/or QGIT cut-offs, as potential risk factors for iTBD. Of 1051 HHC enrolled, 42 (4%) with baseline TBD and 12 (1%) with no baseline TBI test available, were excluded. Of the remaining 997 HHC, 707 (71%) had baseline TBI (TST ≥ 5 mm or QGIT ≥ 0.35 IU/ml). Overall, 20 HHC (2%) developed iTBD (12 cases/1000 person-years, 95%CI: 8–19). HIV infection (aIRR = 29.08, 95% CI: 2.38–355.77, p = 0.01) and undernutrition (aIRR = 6.16, 95% CI: 1.89–20.03, p = 0.003) were independently associated with iTBD. iTBD was not associated with age, diabetes mellitus, smoking, alcohol, and baseline TBI, or iTBI, regardless of TST (≥ 5 mm, ≥ 10 mm, ≥ 6 mm increase) or QGIT (≥ 0.35 IU/ml, ≥ 0.7 IU/ml) cut-offs. Given the high overall risk of iTBD among recently exposed HHCs, and the lack of association between TBI status and iTBD, our findings support the new WHO recommendation to offer TPT to all HHC of PTB patients residing in a high TB burden country such as India, and do not suggest any benefit of TBI testing at baseline or during follow-up to risk stratify recently-exposed HHC for TPT.

Respiratory health status is associated with treatment outcomes in pulmonary tuberculosis

<sec id="st1"> <title>BACKGROUND</title> The association between respiratory impairment and tuberculosis (TB) treatment outcomes is not clear. </sec> <sec id="st2"> <title>METHODS</title> We prospectively evaluated respiratory health status, measured using the Saint George's Respiratory Questionnaire (SGRQ), in a cohort of new adult pulmonary TB cases during and up to 18 months following treatment in India. Associations between total SGRQ scores and poor treatment outcomes of failure, recurrence and all-cause death were measured using multivariable Poisson regression. </sec> <sec id="st3"> <title>RESULTS</title> We enrolled 455 participants contributing 619 person-years at risk; 39 failed treatment, 23 had recurrence and 16 died. The median age was 38 years (interquartile range 26-49); 147 (32%) ever smoked. SGRQ scores at treatment initiation were predictive of death during treatment (14% higher risk per 4-point increase in baseline SGRQ scores, 95%CI 2-28, P = 0.01). Improvement in SGRQ scores during treatment was associated with a lower risk of failure (1% lower risk for every per cent improvement during treatment, 95%CI 1-2, P = 0.05). Clinically relevant worsening in SGRQ scores following successful treatment was associated with a higher risk of recurrence (15% higher risk per 4-point increase scores, 95%CI 4-27, P = 0.004). </sec> <sec id="st4"> <title>CONCLUSION</title> Impaired respiratory health status was associated with poor TB treatment outcomes. The SGRQ may be used to monitor treatment response and predict the risk of death in pulmonary TB. </sec>.

MAL adaptor (TIRAP) S180L polymorphism and severity of disease among tuberculosis patients

OBJECTIVE

Though several genetic variants have been recognized to be associated with susceptibility to Tuberculosis (TB) infection and disease, a recent observation on the association of TIRAP C975T (S180L) variants with TB disease severity in mice model prompted us to assess their relevance in humans. In addition, TIRAP variants have also been reported to be associated with varied circulating Interferon-gamma induced protein (IP-10) levels. We investigated the association of TIRAP variants with severity of TB disease and IP-10 production in humans, which may be useful in predicting poor clinical outcome.

METHODS

Culture positive symptomatic adult pulmonary TB (PTB) patients enrolled between August 2014 and October 2017 were included in this investigation. Allelic discrimination PCR and conventional IP-10 quantification methods were employed for genotyping and IP-10 measurement followed by statistical investigations to analyse patients' variables.

RESULTS

Among 211 participants, C/C allele was identified in 70% (n = 147); 26% (n = 55) and 4% (n = 9) had C/T and T/T alleles respectively. There was no significant association between TIRAP variants and smear grade, chest-X-ray score, symptom severity score and circulating IP-10 levels. However, significant association was observed between i) circulating IP-10 levels and time to Mycobacterium Growth Indicator Tube (MGIT) culture conversion (p =0.032); ii) smear grade among active TB patients and circulating IP-10 levels (p =0 .032).

CONCLUSIONS

Although mice experiments showed promising results with more severe disease in C/C and T/T individuals, we did not observe any such association in humans.

Incidence of tuberculosis in HIV-infected adults on first- and second-line antiretroviral therapy in India

BACKGROUND

Programmatic data on the baseline risk of tuberculosis in people living with HIV (PLHIV) are needed to evaluate long-term effectiveness of the ongoing isoniazid preventive therapy (IPT) roll-out in India.

METHODS

We estimated the incidence rate and risk factors of tuberculosis disease in adult PLHIV initiating first- and second-line anti-retroviral therapy (ART) prior to widespread IPT in a public ART center in Pune, India.

RESULTS

4067 participants contributing 5205.7 person-years of follow-up on first-line ART and 871 participants contributing 1031.7 person-years of follow-up on second-line ART were included in the analysis. The incidence rate of tuberculosis was 4.39 cases (95%CI 3.86-5.00) per 100 person-years on first-line ART and 1.64 cases (95%CI 1.01-2.63) per 100 person-years on second-line ART (p < 0.001). After adjusting for competing risks, male sex (aSHR = 1.33, 95%CI 1.02-1.74, p = 0.03), urban residence (aSHR = 1.53, 95%CI 1.13-2.07, p = 0.006) and CD4+ counts < 350 cells/mm³ (aSHR = 3.06 vs CD4 > 350 cells/mm³, 95%CI 1.58-5.94, p < 0.001) at ART initiation were associated with higher risk of tuberculosis independent of ART regimen.

CONCLUSION

Risk of tuberculosis was lower in PLHIV receiving second-line ART compared to first-line ART. Prioritizing IPT in PLHIV with low CD4+ counts, urban residence and in males may further mitigate the risk of tuberculosis during ART.

Trends in HbA1c levels and implications for diabetes screening in tuberculosis cases undergoing treatment in India

SETTING

The optimal timing of screening for diabetes mellitus (DM) among tuberculosis (TB) cases is unclear due to the possibility of stress hyperglycemia.

DESIGN

We evaluated adult (18 years) pulmonary TB cases at treatment initiation as well as at 3 months, 6 months and 12 months. DM was identified by self-report (known DM) or glycated hemoglobin (HbA1c)  6.5% (new DM). Trends in HbA1c levels during treatment were assessed using non-parametric tests.

RESULTS

Of the 392 participants enrolled, 75 (19%) had DM, 30 (40%) of whom had new DM. Of the 45 participants with known DM, respectively 37 (82%) and 40 (89%) received medication to lower glucose levels at treatment initiation and completion; one participant with new DM initiated glucose-lowering medication during follow-up. The median HbA1c level in participants with known, new and no DM was respectively 10.1% (interquartile range [IQR] 8.3-11.6), 8.5% (IQR 6.7-11.5) and 5.6% (IQR 5.3-5.9) at treatment initiation, and 8.7% (IQR 6.8-11.3), 7.1% (IQR 5.8-9.5) and 5.3% (IQR 5.1-5.6) at treatment completion (P < 0.001). Overall, 5 (12%) with known and 13 (43%) with new DM at treatment initiation had reverted to HbA1c < 6.5% by treatment completion (P = 0.003); the majority of reversions occurred during the first 3 months, with no significant reversions beyond 6 months.

CONCLUSION

HbA1c levels declined with anti-tuberculosis treatment. Repeat HbA1c testing at treatment completion could reduce the risk of misdiagnosis of DM.

Smoking, alcohol use disorder and tuberculosis treatment outcomes: A dual co-morbidity burden that cannot be ignored

BACKGROUND

More than 20% of tuberculosis (TB) disease worldwide may be attributable to smoking and alcohol abuse. India is the second largest consumer of tobacco products, a major consumer of alcohol particularly among males, and has the highest burden of TB globally. The impact of increasing tobacco dose, relevance of alcohol misuse and past versus current or never smoking status on TB treatment outcomes remain inadequately defined.

METHODS

We conducted a multi-centric prospective cohort study of newly diagnosed adult pulmonary TB patients initiated on TB treatment and followed for a minimum of 6 months to assess the impact of smoking status with or without alcohol abuse on treatment outcomes. Smokers were defined as never smokers, past smokers or current smokers. Alcohol Use Disorder Identification Test (AUDIT) scores were used to assess alcohol misuse. The association between smoking status and treatment outcomes was assessed in univariate and multivariate random effects poisson regression models.

RESULTS

Of 455 enrolled, 129 (28%) had a history of smoking with 94 (20%) current smokers and 35 (8%) past smokers. Unfavourable treatment outcomes were significantly higher among past and current smokers as compared to never smokers. Specifically, the risk of treatment failure was significantly higher among past smokers (aIRR = 2.66, 95% CI: 1.41-4.90, p = 0.002), recurrent TB among current smokers (aIRR = 2.94, 95% CI: 1.30-6.67, p = 0.010) and death among both past (2.63, 95% CI: 1.11-6.24, p = 0.028) and current (aIRR = 2.59, 95% CI: 1.29-5.18, p = 0.007) smokers. Furthermore, the combined effect of alcohol misuse and smoking on unfavorable treatment outcomes was significantly higher among past smokers (aIRR: 4.67, 95% CI: 2.17-10.02, p<0.001) and current smokers (aIRR: 3.58, 95% CI: 1.89-6.76, p<0.001).

CONCLUSION

Past and current smoking along with alcohol misuse have combined effects on increasing the risk of unfavourable TB treatment outcomes. Innovative interventions that can readily address both co-morbidities are urgently needed.

Assessment of lung function in successfully treated tuberculosis reveals high burden of ventilatory defects and COPD

Background

Burden, phenotype and risk-factors of lung function defects in successfully treated tuberculosis cases are unclear.

Methods

We performed spirometry with bronchodilators in new drug-sensitive adult (≥18 years) pulmonary tuberculosis cases during the 12 months following successful treatment in India. Airflow obstruction was defined as pre-bronchodilator FEV1/FVC<5^th percentile of Global Lung Initiative mixed-ethnicity reference (lower limit of normal [LLN]). Chronic obstructive pulmonary disease (COPD) was defined as post-bronchodilator FEV1/FVC<LLN among participants with obstruction. Restrictive spirometry pattern was defined as FVC<LLN among participants without obstruction. Multivariable logistic and linear regression was used to identify risk-factors for obstruction, restriction and low lung function despite successful treatment.

Results

Of the 172 participants included in the analysis, 82 (48%) were female, 22 (13%) had diabetes and 34 (20%) ever-smoked with a median (IQR) exposure of 3.5 (0.2–9.9) pack-years. Median (IQR) age and body-mass index (BMI) at enrollment was 32 (23–39) years and 18.1 (16.0–20.5) kg/m² respectively. Airflow obstruction was detected in 42 (24%) participants; of whom 9 (21%) responded to short-acting bronchodilators and 25 (56%) had COPD; and was associated with duration of illness prior to treatment (aOR = 1.32 per 30-days, 95%CI 1.04–1.68, p = 0.02). A restrictive spirometry pattern was detected in 89 (52%) participants and was associated with female sex (aOR = 3.73, 95%CI 1.51–9.17, p = 0.004) and diabetes (aOR = 4.06, 95%CI 1.14–14.42, p = 0.03). Higher HbA1c at treatment initiation was associated with greater odds of a restrictive spirometry pattern (aOR = 1.29 per unit higher HbA1c, 95%CI 1.04 to 1.60, p = 0.02).

Conclusion

We found a high burden of lung function defects and COPD in tuberculosis cases who successfully completed treatment. Screening for chronic lung diseases following treatment and linkage to respiratory health clinics should be included in the routine management plan of all tuberculosis cases in India, regardless of conventional COPD risk-factors such as older age and smoking.

Factors associated with pulmonary impairment in HIV-infected South African adults

Background

HIV-infected individuals have increased risk of developing obstructive lung disease (OLD). Studies from developed countries report high viral load, low CD4 counts, and anti-retroviral therapy (ART) to be associated with OLD; but these findings may not be generalizable to populations in resource-limited settings.

Methods

We conducted a prospective cohort study of lung function in 730 HIV-infected black South African adults. Pre-bronchodilator spirometry was performed at enrollment and repeated annually for three years. Logistic regression models were used to identify factors associated with OLD, defined as FEV1/FVC<0.70, at enrollment. Excess annual declines in FEV1 and FVC were modelled as the product-term of follow-up time and exposures using random effects regression.

Results

Median (IQR) age at enrollment was 36 (32–41) years, 85% were female and 30% ever-smoked with a median (IQR) exposure of 3 (1–6) pack-years. Median (IQR) CD4 count and viral load at enrollment were 372 (261–518) cells/mm³ and 2655 (91–13,548) copies/mL respectively. Overall, 25% were receiving ART at enrollment, 16% of whom reported at least 6 months of ART receipt. OLD was found in 35 (5%) at enrollment. Increasing age (aOR = 2.08 per 10-years [95%CI 1.22–3.57], p = 0.007), current smoking (aOR = 3.55 [95%CI 1.20–10.53], p = 0.02), and CRP (aOR = 1.01 per unit-increase [95%CI 1.00–1.03], p = 0.04) were significantly associated with OLD at enrollment; while increasing CD4 count (aOR = 1.02 per-100 cells/mm³ [95%CI 0.85–1.22], p = 0.82), viral load (aOR = 0.67 per log-increase [95%CI 0.43–1.10], p = 0.12) and receipt of ART (aOR = 0.57 [95%CI 0.18–1.75], p = 0.32) were not. The median (IQR) follow-up time was 18 (12–24) months. Participants with a history of tuberculosis (TB) had a 35 mL (95%CI 2–68, p = 0.03) and 57 mL (95%CI 19–96, p = 0.003) per year excess loss of FEV1 and FVC respectively.

Conclusion

Prevalent OLD was associated with older age, current smoking and higher CRP levels, but not CD4 counts and ART, in HIV-infected South African adults. Better understanding of the long-term effects of TB, smoking and inflammation on lung function in HIV-infected populations is urgently needed.