Impact of emphysema on sputum culture conversion in male patients with pulmonary tuberculosis: a retrospective analysis

Risk of lung diseases in patients with previous carbon monoxide poisoning: a nationwide population-based cohort study in the Republic of Korea

INTRODUCTION

Carbon monoxide poisoning is associated with severe damage to various organs. In this study, we aimed to determine if previous carbon monoxide poisoning was associated with an increased risk of lung diseases.

METHODS

The study population was derived from the National Health Insurance Service database of Korea between 1 January 2002 and 31 December 2021. Adults with carbon monoxide poisoning, with at least one visit to medical facilities between 2002 and 2021, were included. For comparison, an equal number of matched controls with the same index date were selected from the database.

RESULTS

A total of 28,618 patients with carbon monoxide poisoning and 28,618 matched controls were included in this study. Approximately 42.8 per cent of the patient and control groups were female, with a mean age of 51.3 years. In patients with carbon monoxide poisoning, there was a significant increase in the risk of lung cancer (adjusted hazard ratio, 1.84; 95 per cent confidence interval, 1.42-2.39; P < 0.001), chronic obstructive pulmonary disease (adjusted hazard ratio, 1.60; 95 per cent confidence interval, 1.36-1.89; P < 0.001), pulmonary tuberculosis (adjusted hazard ratio, 1.46; 95 per cent confidence interval, 1.13-1.88; P = 0.003), and non-tuberculous mycobacterial infection (adjusted hazard ratio, 1.54; 95 per cent confidence interval, 1.01-2.36; P = 0.047).

DISCUSSION

In this retrospective cohort study, previous carbon monoxide poisoning was associated with an increased risk of lung cancer, chronic obstructive pulmonary disease, pulmonary tuberculosis, and non-tuberculous mycobacterial infection. Further studies are needed to confirm such an association in other populations and the risk of lung diseases due to the toxic effect of carbon monoxide from different sources.

CONCLUSIONS

Previous carbon monoxide poisoning was associated with an increased risk of lung diseases, but the relative importance of the causes and sources of exposure was not known. The long-term management of survivors of acute carbon monoxide poisoning should include monitoring for lung cancer, chronic obstructive pulmonary disease, pulmonary tuberculosis, and non-tuberculous mycobacterial infection.

Is Tobacco Use Associated With Risk of Recurrence and Mortality Among People With TB?: A Systematic Review and Meta-Analysis

BACKGROUND

Associations between tobacco use and poor TB treatment outcomes are well documented. However, for important outcomes such as TB recurrence or relapse and mortality during treatment, as well as for associations with smokeless tobacco (ST), the evidence is not summarized systematically.

RESEARCH QUESTION

Is tobacco use associated with risk of poor treatment outcomes among people with TB?

STUDY DESIGN AND METHODS

The MEDLINE, Embase, and Cumulative Index of Nursing and Allied Health Literature databases were searched on November 22, 2021. Epidemiologic studies reporting associations between tobacco use and at least one TB treatment outcome were eligible. Independent double-screening, extractions, and quality assessments were undertaken. Random effects meta-analyses were conducted for the two primary review outcomes (TB recurrence or relapse and mortality during treatment), and heterogeneity was explored using subgroups. Other outcomes were synthesized narratively.

RESULTS

Our searches identified 1,249 records, of which 28 were included in the meta-analyses. Based on 15 studies, higher risk of TB recurrence or relapse was found with ever using tobacco vs never using tobacco (risk ratio [RR], 1.78; 95% CI, 1.31-2.43; I2 = 85%), current tobacco use vs no tobacco use (RR, 1.95; 95% CI, 1.59-2.40; I2 = 72%), and former tobacco use vs never using tobacco (RR, 1.84; 95% CI, 1.21-2.80; I2 = 4%); heterogeneity arose from differences in study quality, design, and participant characteristics. Thirty-eight studies were identified for mortality, of which 13 reported mortality during treatment. Ever tobacco use (RR, 1.55; 95% CI, 1.32-1.81; I2 = 0%) and current tobacco use (RR, 1.51; 95% CI, 1.09-2.10; I2 = 87%) significantly increased the likelihood of mortality during treatment among people with TB compared with never using tobacco and not currently using tobacco, respectively; heterogeneity was explained largely by differences in study design. Almost all studies in the meta-analyses scored high or moderate on quality assessments. Narrative synthesis showed that tobacco use was a risk factor for other unfavorable TB treatment outcomes, as previously documented. Evidence on ST was limited, but identified studies suggested an increased risk for poor outcomes with its use compared with not using it.

INTERPRETATION

Tobacco use significantly increases the risk of TB recurrence or relapse and mortality during treatment among people with TB, highlighting the need to address tobacco use to improve TB outcomes.

TRIAL REGISTRY

PROSPERO; No.: CRD42017060821; URL: https://www.crd.york.ac.uk/prospero/.

Utility of Machine Learning and Radiomics Based on Cavity for Predicting the Therapeutic Response of MDR-TB

Background

Sputum culture result at the sixth month is essential for predicting therapeutic response to longer multidrug-resistant tuberculosis (MDR-TB) regimens. This study aimed to construct a predictive model using cavity-based radiomics to predict sputum status at the sixth month for MDR-TB patients treated with longer regimens.

Methods

This retrospective study recruited 315 MDR-TB patients treated with longer regimens from two centers (250 patients from center 1 and 65 patients from center 2), who were divided into persistently positive and conversion to negative sputum culture groups according to sputum results. Radiomics features were extracted based on the cavity, and a radiomics model was selected and established using a random forest classifier. The clinical characteristics and primary CT signs with significant differences were integrated to build a clinical model. A combined model was generated using the radiomics and clinical model. ROC curves, F1-score and DCA curves were used to assess the predictive performance of the models.

Results

Twenty-eight radiomics features were selected to build a radiomics model for predicting the sputum status. The radiomics model achieved good performance, with AUCs of 0.892 and 0.839 in the training and testing cohort, respectively, which was similar to the performance of the combined model (0.913 and 0.815) and much higher than that of the clinical model (0.688 and 0.525) in the two cohorts.

Conclusion

The cavity-based radiomics model has the potential to predict sputum culture status for MDR-TB patients receiving longer regimens, which could guide follow-up treatment effectively.

Impact of emphysema on the prognosis of Mycobacterium avium complex pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a major comorbid disease of Mycobacterium avium complex pulmonary disease (MAC-PD). Emphysema is one of the main pathological findings in COPD, a risk factor for chronic pulmonary aspergillosis (CPA), and is associated with poor prognosis. We aimed to clarify the effect of emphysema on mortality in MAC-PD.

METHODS

We retrospectively analyzed 203 patients with MAC-PD at The Jikei Daisan Hospital between January 2014 and December 2018. We investigated the mortality and CPA development rates after MAC-PD diagnosis in patients with or without emphysema.

RESULTS

Multivariate Cox proportional hazards regression analysis showed the following negative prognostic factors in patients with MAC-PD: emphysema (hazard ratio [HR]: 11.46; 95% confidence interval [CI]: 1.30-100.90; P = 0.028); cavities (HR: 3.12; 95% CI: 1.22-7.94; P = 0.017); and low body mass index (<18.5 kg/m²) (HR: 4.62; 95% CI: 1.63-13.11; P = 0.004). The mortality and occurrence of CPA were higher in MAC-PD patients with than without emphysema (log-rank test, P < 0.0001 and P < 0.0001).

CONCLUSION

Our study findings showed that emphysema detected by computed tomography was associated with an increased risk of CPA development and mortality in MAC-PD.