Chronic inactive pulmonary tuberculosis and treatment sequelae: chest radiographic features

Immunologic and imaging signatures in post tuberculosis lung disease

Post Tuberculosis Lung Disease (PTLD) affects millions of tuberculosis survivors and is a global health burden. The immune mechanisms that drive PTLD are complex and have historically been under investigated. Here, we discuss two immune-mediated paradigms that could drive human PTLD. We review the characteristics of a fibrotic granuloma that favors the development of PTLD via an abundance of T-helper-2 and T-regulatory cells and an upregulation of TGF-β mediated collagen deposition. Next, we discuss the post-primary tuberculosis paradigm and the complex mixture of caseous pneumonia, cavity formation and fibrosis that can also lead to PTLD. We review the delicate balance between cellular subsets and cytokines of the innate and adaptive immune system in conjunction with host-derived proteases that can perpetuate the parenchymal lung damage seen in PTLD. Next, we discuss the role of novel host directed therapies (HDT) to limit the development of PTLD and in particular, the recent repurposing of established medications such as statins, metformin and doxycycline. Finally, we review the emerging role of novel imaging techniques as a non-invasive modality for the early recognition of PTLD. While access to computed tomography imaging is unlikely to be available widely in countries with a high TB burden, its use in research settings can help phenotype PTLD. Due to a lack of disease-specific biomarkers and controlled clinical trials, there are currently no evidence-based recommendations for the management of PTLD. It is likely that an integrated antifibrotic strategy that could simultaneously target inflammatory and pro-fibrotic pathways will probably emerge as a successful way to treat this complex condition. In a disease spectrum as wide as PTLD, a single immunologic or radiographic marker may not be sufficient and a combination is more likely to be a successful surrogate that could aid in the development of successful HDTs.

A systematic review of clinical outcomes on the WHO Category II retreatment regimen for tuberculosis

OBJECTIVE

To assess the clinical outcomes of patients prescribed the World Health Organization (WHO) Category II retreatment regimen for tuberculosis (TB).

DESIGN

A systematic review of the literature was performed by searching Medscape, Embase and Scopus databases for cohort studies and clinical trials reporting outcomes in adult patients on the Category II retreatment regimen.

RESULTS

The proportion of patients successfully completing the retreatment regimen varied from 27% to 92% in the 39 studies included in this review. In only 2/39 (5%) studies was the treatment success rate > 85%. There are very few data concerning outcomes in patients categorised as 'other', and outcomes in this subgroup are variable. Of the five studies reporting disaggregated outcomes in human immunodeficiency virus (HIV) positive people, four demonstrated worse outcomes than in HIV-negative people on the retreatment regimen. Only four studies reported disaggregated outcomes in patients with isoniazid (INH) resistance, and treatment success rates varied from 11% to 78%.

CONCLUSION

Clinical outcomes on the Category II retreatment regimen are poor across various populations. Improvements in management should consider the holistic treatment of comorbidity and comprehensive approaches to drug resistance in patients with recurrent TB, including a standardised approach for the management of INH resistance in patients who develop recurrent TB in settings without reliable access to comprehensive drug susceptibility testing.

Color Doppler Twinkling Artifact in Diagnosis of Tuberculous Pleuritis: A Comparison with Gray-Scale Ultrasonography and Computed Tomography

The aim of this study was to determine whether twinkling artifact (TA) detected on color Doppler ultrasonography can effectively determine the presence of pleural calcification compared with computed tomography (CT) and differentiate tuberculous pleuritis (TP) and cancerous pleuritis (CP). One hundred six cases of TP and 26 cases of CP were scanned using gray-scale ultrasonography (GSU) and TA to determine the presence of pleural calcification. With CT as the reference standard, 63.3% and 79.6% of patients with pleural calcification were identified with GSU and TA, respectively. The detection rate of TA was higher than that of GSU (p = 0.039). For the whole study population, 37.1% were identified as having pleural calcification with CT, significantly higher than the proportion detected with GSU (25.8%, p = 0.001), but not different from that detected with TA (41.7%, p = 0.327). The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of TA were 79.6%, 80.7%, 80.3%, 70.9% and 87.0%, respectively. The detection rate of TA was significantly higher than that of GSU (p <0.001). When GSU was combined with TA (GSUTA), the positive rate in the TP group was significantly higher than that in the CP group (χ² < 0.001). In conclusion, TA is comparable to CT and more sensitive than GSU in the detection of pleural calcification. Evaluation for GSUTA on pleura may help to differentiate TP from CP.

Imaging Manifestations of Thoracic Tuberculosis

Despite significant improvements in the diagnosis and treatment of tuberculosis achieved during the last 3 decades, tuberculosis still remains one of the deadliest communicable diseases worldwide. Tuberculosis is still present in all regions of the world, with a more significant impact in developing countries. This article reviews the most common imaging manifestations of primary and postprimary tuberculosis, their complications, and the critical role of imaging in the diagnosis and follow-up of affected patients.

Tuberculosis associates with both airflow obstruction and low lung function: BOLD results

In small studies and cases series, a history of tuberculosis has been associated with both airflow obstruction, which is characteristic of chronic obstructive pulmonary disease, and restrictive patterns on spirometry. The objective of the present study was to assess the association between a history of tuberculosis and airflow obstruction and spirometric abnormalities in adults.The study was performed in adults, aged 40 years and above, who took part in the multicentre, cross-sectional, general population-based Burden of Obstructive Lung Disease study, and had provided acceptable post-bronchodilator spirometry measurements and information on a history of tuberculosis. The associations between a history of tuberculosis and airflow obstruction and spirometric restriction were assessed within each participating centre, and estimates combined using meta-analysis. These estimates were stratified by high- and low/middle-income countries, according to gross national income.A self-reported history of tuberculosis was associated with airflow obstruction (adjusted odds ratio 2.51, 95% CI 1.83-3.42) and spirometric restriction (adjusted odds ratio 2.13, 95% CI 1.42-3.19).A history of tuberculosis was associated with both airflow obstruction and spirometric restriction, and should be considered as a potentially important cause of obstructive disease and low lung function, particularly where tuberculosis is common.