Reduced lung function and health-related quality of life after treatment for pulmonary tuberculosis in Gambian children: a cross-sectional comparative study

A scoping review of interventions to address TB associated respiratory disability

There is a growing body of data describing a high burden of respiratory morbidity amongst pulmonary TB patients and survivors, with up to half thought to experience residual respiratory symptoms, abnormal spirometry, or structural pathology after TB treatment completion. Many patients experiencing marked impacts on their lives and livelihoods. However, there remain no guidelines or evidence-based frameworks for integrated TB-respiratory care during or post TB treatment completion. In this scoping review, completed in collaboration with the WHO Global Tuberculosis Programme, we have identified a lack of primary data on the clinical efficacy, cost effectiveness or feasibility of six potential interventions for the prevention and management of TB-associated respiratory impairment and disability, with a lack of studies in children and adolescents. There is a need for robust interventional trials to improve the long-term respiratory outcomes of people affected by pulmonary TB disease, and to explore how these might be implemented within resource-limited settings.

Pulmonary function outcomes after tuberculosis treatment in children: a systematic review and meta-analysis

BACKGROUND

Despite tuberculosis (TB) being a curable disease, current guidelines fail to account for the long-term outcomes of post-tuberculosis lung disease-a cause of global morbidity despite successful completion of effective treatment. Our systematic review aimed to synthesise the available evidence on the lung function outcomes of childhood pulmonary tuberculosis (PTB).

METHODS

PubMed, ISI Web of Science, Cochrane Library and ProQuest databases were searched for English-only studies without time restriction (latest search date 22 March 2023). Inclusion criteria were (1) patients who had TB with pulmonary involvement at age ≤18 years; (2) pulmonary function tests (PFTs) performed on patients after treatment completion; and (3) observational studies, including cohort and cross-sectional studies. We adhered to the recommendations of the Cochrane Collaboration and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

RESULTS

From 8040 records, 5 studies were included (involving n=567 children), with spirometry measures from 4 studies included in the meta-analyses. The effect sizes of childhood TB on forced expiratory volume in the first second and forced vital capacity z-scores were estimated to be -1.53 (95% CI -2.65, -0.41; p=0.007) and -1.93 (95% CI -3.35, -0.50; p=0.008), respectively.

DISCUSSION

The small number of included studies reflects this under-researched area, relative to the global burden of TB. Nevertheless, as childhood PTB impacts future lung function, PFTs (such as spirometry) should be considered a routine test when evaluating the long-term lung health of children beyond their completion of TB treatment. PROSPERO registration number CRD42021250172.

Impaired lung function in adolescents with pulmonary tuberculosis during treatment and following treatment completion

Background

Little is known about post-tuberculosis lung disease in adolescents. We prospectively assessed lung function in adolescents with microbiologically confirmed pulmonary tuberculosis during treatment and after treatment completion.

Methods

In a prospective study, we enrolled adolescents diagnosed with microbiologically confirmed tuberculosis and healthy tuberculosis-exposed household controls, between October 2020 and July 2021 in Cape Town, South Africa. Spirometry, plethysmography, diffusion capacity lung function tests and 6-min walking test (6MWT) were completed according to international guidelines 2 months into treatment and following treatment completion. Abnormal lung function was defined as abnormal spirometry (z-score < -1.64 for forced expiratory volume in 1 s (FEV1) and/or forced vital capacity (FVC) and/or FEV1/FVC), plethysmography (total lung capacity (TLC) < 80% of predicted, residual volume over TLC of >45%) and/or diffusion capacity (DLCO z-score < -1.64).

Findings

One-hundred adolescents were enrolled; 50 (50%) with tuberculosis and 50 (50%) healthy tuberculosis-exposed controls. Of the 50 adolescents with tuberculosis, ten had multidrug-resistant tuberculosis. Mean age of the group was 14.9 years (SD 2.7), 6 (6.0%) were living with HIV and 9 (9.0%) were previously treated for tuberculosis. Lung function improved over time; during treatment abnormal lung function was found in 76% of adolescents with tuberculosis, compared to 65% after treatment completion. Spirometry indices were lower in adolescents with tuberculosis compared to controls, both at 2 months and after treatment completion. Plethysmography in adolescents with tuberculosis showed that air-trapping was more common during treatment than in controls (12% vs 0%, respectively, p = 0.017); which improved following treatment completion. Adolescents with tuberculosis both during and after treatment completion walked a shorter distance than controls.

Interpretation

Adolescents with tuberculosis have impaired lung function even after treatment completion. It is crucial to include adolescents in trials on the prevention and treatment of tuberculosis-associated respiratory morbidity.

Funding

EDCTP, National Institute of Health, Medical Research Council, BMBF.

Post-tuberculosis Sequelae in Children

Tuberculosis (TB) is a global health problem especially in the Indian subcontinent imposing significant physical, psychosocial and economic burden on the society. Most national programs define TB cure as completion of treatment with improvement in clinical symptoms, microbiological and radiological clearance. However, follow up these patients for long-term sequelae or complications has not got adequate attention. Post-TB lung disease, neurological deficits and spinal deformities are some of the post-TB sequelae reported in adults, with scanty data available for children. With this review authors attempt to discuss various post-TB disease manifestations and the risk factors associated with their development in children. They address the need to create awareness amongst physicians involved in managing children with TB and obtain more scientific data in this field.

Global burden of disease due to rifampicin-resistant tuberculosis: a mathematical modeling analysis

In 2020, almost half a million individuals developed rifampicin-resistant tuberculosis (RR-TB). We estimated the global burden of RR-TB over the lifetime of affected individuals. We synthesized data on incidence, case detection, and treatment outcomes in 192 countries (99.99% of global tuberculosis). Using a mathematical model, we projected disability-adjusted life years (DALYs) over the lifetime for individuals developing tuberculosis in 2020 stratified by country, age, sex, HIV, and rifampicin resistance. Here we show that incident RR-TB in 2020 was responsible for an estimated 6.9 (95% uncertainty interval: 5.5, 8.5) million DALYs, 44% (31, 54) of which accrued among TB survivors. We estimated an average of 17 (14, 21) DALYs per person developing RR-TB, 34% (12, 56) greater than for rifampicin-susceptible tuberculosis. RR-TB burden per 100,000 was highest in former Soviet Union countries and southern African countries. While RR-TB causes substantial short-term morbidity and mortality, nearly half of the overall disease burden of RR-TB accrues among tuberculosis survivors. The substantial long-term health impacts among those surviving RR-TB disease suggest the need for improved post-treatment care and further justify increased health expenditures to prevent RR-TB transmission.

Effect of smoking on the development of chronic obstructive pulmonary disease in young individuals: a nationwide cohort study

Background

Cigarette smoking is an important risk factor for developing chronic obstructive pulmonary disease (COPD). However, the effect of smoking on the development of COPD in young individuals remains unclear. We aimed to evaluate the effect of smoking on COPD development in young individuals.

Methods

Using the Korean National Health Information Database, we screened individuals aged 20-39 years who participated in the national health check-up between 2009 and 2012. We defined physician-diagnosed COPD based on health insurance claims and searched the database until December 2019. We identified 6,307,576 eligible individuals, and 13,789 had newly developed COPD. We used multivariate Cox proportional hazards models to estimate the adjusted hazard ratio (aHR) of risk factors for COPD.

Results

The incidence rate for developing COPD was 0.26/1000 person-year. The risk of developing COPD was significantly higher in current smokers [aHR 1.46, 95% confidence interval (CI) 1.39-1.53] and former smokers (aHR 1.21, 95% CI 1.14-1.29) than in non-smokers. Furthermore, the risk increased with increasing smoking amounts (≥20 pack-years, aHR 2.24; 10-20 pack-years, aHR 1.55; <10 pack-years, aHR 1.27). Female participants had a higher relative risk of developing COPD due to smoking, compared with their male counterparts.

Conclusion

Cigarette smoking increased the risk of developing COPD in young individuals. Current and heavy smokers had higher risks of developing COPD than non-smokers. Female smokers were more likely to develop COPD than male smokers.

Residual respiratory disability after successful treatment of pulmonary tuberculosis: a systematic review and meta-analysis

Background

Pulmonary tuberculosis (PTB) can result in long-term health consequences, even after successful treatment. We conducted a systematic review and meta-analysis to estimate the occurrence of respiratory impairment, other disability states, and respiratory complications following successful PTB treatment.

Methods

We identified studies from January 1, 1960, to December 6, 2022, describing populations of all ages that successfully completed treatment for active PTB and had been assessed for at least one of the following outcomes: occurrence of respiratory impairment, other disability states, or respiratory complications following PTB treatment. Studies were excluded if they reported on participants with self-reported TB, extra-pulmonary TB, inactive TB, latent TB, or if participants had been selected on the basis of having more advanced disease. Study characteristics and outcome-related data were abstracted. Meta-analysis was performed using a random effects model. We adapted the Newcastle Ottawa Scale to evaluate the methodological quality of the included studies. Heterogeneity was assessed using the I² statistic and prediction intervals. Publication bias was assessed using Doi plots and LFK indices. This study is registered with PROSPERO (CRD42021276327).

Findings

61 studies with 41,014 participants with PTB were included. In 42 studies reporting post-treatment lung function measurements, 59.1% (I² = 98.3%) of participants with PTB had abnormal spirometry compared to 5.4% (I² = 97.4%) of controls. Specifically, 17.8% (I² = 96.6%) had obstruction, 21.3% (I² = 95.4%) restriction, and 12.7% (I² = 93.2%) a mixed pattern. Among 13 studies with 3179 participants with PTB, 72.6% (I² = 92.8%) of participants with PTB had a Medical Research Council dyspnoea score of 1-2 and 24.7% (I² = 92.2%) a score of 3-5. Mean 6-min walk distance in 13 studies was 440.5 m (I² = 99.0%) in all participants (78.9% predicted, I² = 98.9%) and 403.0 m (I² = 95.1%) among MDR-TB participants in 3 studies (70.5% predicted, I² = 97.6%). Four studies reported data on incidence of lung cancer, with an incidence rate ratio of 4.0 (95% CI 2.1-7.6) and incidence rate difference of 2.7 per 1000 person-years (95% CI 1.2-4.2) when compared to controls. Quality assessment indicated overall low-quality evidence in this field, heterogeneity was high for pooled estimates of nearly all outcomes of interest, and publication bias was considered likely for almost all outcomes.

Interpretation

The occurrence of post-PTB respiratory impairment, other disability states, and respiratory complications is high, adding to the potential benefits of disease prevention, and highlighting the need for optimised management after successful treatment.

Funding

Canadian Institutes of Health Research Foundation Grant.

The Long-Term Impact of Early-Life Tuberculosis Disease on Child Health: A Prospective Birth Cohort Study

Rationale: There is growing concern that post-tuberculosis disease (TB) sequelae and morbidity are substantial, but no studies have controlled for preexisting factors before disease. Whether children have post-TB morbidity is not well characterized. Objectives: To assess the effect of a TB diagnosis on wheezing episodes, lung function, and anthropometric measurements among children enrolled in a prospective birth cohort study in South Africa. Methods: We prospectively followed children from birth through 5 years for TB using diagnostic tests including chest radiography and repeated induced sputum sample testing with Xpert MTB/RIF and liquid culture. We longitudinally measured health outcomes including growth, wheezing, and lung function up to 5 years. Mixed-effects linear regression models were used to assess growth and lung function after TB. Poisson regression was used to assess risk of subsequent wheezing. Measurements and Main Results: Among 1,068 participants, 96 TB cases occurred (1,228 cases per 100,000 person-years [95% confidence interval (CI), 1,006-1,500]) occurred over 7,815 child-years of follow-up. TB was associated with lower length-for-age (-0.40 [95% CI, -0.68 to -0.11]), weight-for-age (-0.30 [95% CI, -0.59 to -0.01]), and body mass index (-0.54 [95% CI, -0.83 to -0.25]) z-scores at 5 years. Children developing TB were consistently more likely to wheeze regardless of the timing of TB. Children with diagnoses of TB between 0 and 1 year of age had reduced time to peak tidal expiratory flow over total expiratory time (-2.35% [95% CI, -4.86% to -0.17%]) and higher fractional exhaled nitric oxide (2.88 ppb [95% CI, 0.57-5.19 ppb]) at 5 years. Children with diagnoses of TB between 1 and 4 years of age had impaired Vt (-9.32 ml [95% CI, -14.89 to -3.75 ml]) and time to peak tidal expiratory flow over total expiratory time (-2.73% [95% CI, -5.45% to -0.01%]) at 5 years. Conclusions: Prevention of TB disease in the first few years of life may have substantial long-term benefits through childhood.

UMOYA: a prospective longitudinal cohort study to evaluate novel diagnostic tools and to assess long-term impact on lung health in South African children with presumptive pulmonary TB-a study protocol

BACKGROUND

Despite a high paediatric tuberculosis (TB) burden globally, sensitive and specific diagnostic tools are lacking. In addition, no data exist on the impact of pulmonary TB on long-term child lung health in low- and middle-income countries. The prospective observational UMOYA study aims (1) to build a state-of-the-art clinical, radiological, and biological repository of well-characterised children with presumptive pulmonary TB as a platform for future studies to explore new emerging diagnostic tools and biomarkers for early diagnosis and treatment response; and (2) to investigate the short and long-term impact of pulmonary TB on lung health and quality of life in children.

METHODS

We will recruit up to 600 children (0-13 years) with presumptive pulmonary TB and 100 healthy controls. Recruitment started in November 2017 and is expected to continue until May 2023. Sputum and non-sputum-based samples are collected at enrolment and during follow-up in TB cases and symptomatic controls. TB treatment is started by routine care services. Intensive follow-up for 6 months will allow for TB cases to retrospectively be classified according to international consensus clinical case definitions for TB. Long-term follow-up, including imaging, comprehensive assessment of lung function and quality of life questionnaires, are done yearly up to 4 years after recruitment.

DISCUSSION

The UMOYA study will provide a unique platform to evaluate new emerging diagnostic tools and biomarkers for early diagnosis and treatment response and to investigate long-term outcomes of pulmonary TB and other respiratory events on lung health in children.

A scoping review of lung function in children and adolescents living with HIV in the era of antiretroviral treatment

BACKGROUND

Human immunodeficiency virus (HIV) in children and adolescents remains an important health challenge in many countries and is commonly associated with lung disease. The introduction of antiretroviral therapy (ART) has greatly improved survival but chronic lung disease is a common ongoing challenge. We conducted a scoping review of studies that have reported lung function in school-aged children and adolescents living with HIV.

METHODS

A systematic literature search was performed by searching Medline, Embase, and PubMed databases, limited to articles published between 2011 and 2021 in English language. Inclusion criteria were studies involving participants living with HIV aged 5-18 years and having spirometry data. The primary outcome was lung function as measured by spirometry.

RESULTS

Twenty-one studies were included in the review. Most study participants were living in the sub-Saharan African region. The prevalence of reduced forced expiratory volume in 1 s (FEV₁ ) ranged from 25.3% to 73% across studies, reduced forced vital capacity (FVC) ranged from 10% to 42% and reduced FEV₁ /FVC ranged from 3% to 26%. The mean z-score of FEV₁ ranged from -2.19 to -0.73, mean zFEV₁ /FVC ranged from -0.74 to 0.2, and mean FVC ranged from -1.86 to -0.63.

CONCLUSION

There is a high prevalence of lung function impairment in children and adolescents living with HIV, which persists in the ART era. Further studies are needed of interventions that might improve lung function in these vulnerable populations.

Magnitude and factors associated with post-tuberculosis lung disease in low- and middle-income countries: A systematic review and meta-analysis

BACKGROUND

Emerging evidence suggests that after completion of treatment for tuberculosis (TB) a significant proportion of patients experience sequelae. However, there is limited synthesized evidence on this from low-income countries, from Sub-Saharan Africa, and in HIV infected individuals. We seek to provide an updated comprehensive systematic review and meta-analysis on the magnitude and factors associated with post-TB lung disease (PTLD) in low- and middle-income countries (LMICs).

METHODS

We searched PubMed, Embase and CINAHL for studies from LMICs with data on post-TB lung health in patients who had previously completed treatment for pulmonary TB. Data on study characteristics, prevalence of PTLD-specifically abnormal lung function (spirometry), persisting respiratory symptoms and radiologic abnormalities were abstracted. Statistical analysis was performed using Microsoft Excel and R version 4.1 software, and random effects meta-analysis conducted to compute pooled prevalence of PTLD, evaluate heterogeneity, and assess factors associated with PTLD.

RESULTS

We identified 32 eligible studies with 6225 participants. Twenty-one studies were from Africa, 16 included HIV infected participants, spirometry was conducted in 20 studies, symptom assessment in 16 and chest imaging in eight. Pooled prevalence of abnormal lung function was 46.7%, persistent respiratory symptoms 41.0%, and radiologic abnormalities 64.6%. Magnitude of any type of PTLD varied by HIV status (HIV- 66.9%, HIV+ 32.8%, p = 0.0013), across geographic setting (SE Asia 57.5%, Southern America 50.8%, and Africa 38.2%, p = 0.0118), and across urban-rural settings (symptom prevalence: rural 68.8%, urban 39.1%, mixed settings 27.9%, p = 0.0035), but not by income settings, sex or age-group.

CONCLUSIONS

There is high burden of post-TB persistent respiratory symptoms, functional lung impairment and radiologic structural abnormalities in individuals living in LMICs. Burden varies across settings and by HIV status. This evidence may be valuable to advocate for and inform implementation of structured health care specific to the needs of this vulnerable population of individuals.