Background: Adenosine deaminase (ADA) activity is typically elevated in patients with tuberculous pleural effusion (TPE), but low ADA has occasionally been reported in patients with TPE. The characteristics of these patients are not well-known, and erroneous exclusion of the possibility of TPE can result in a delayed diagnosis. This study investigated the characteristics of patients with TPE who had low ADA activity.Methods: We retrospectively reviewed patients with microbiologically or pathologically confirmed TPE between 2012 to 2018 in a tertiary hospital in South Korea. Patients were categorised into two groups: high ADA (≥40 IU/L) and low ADA (< 40 IU/L). Clinical characteristics and Sequential Organ Failure Assessment (SOFA) scores were compared between groups.Results: A total of 192 patients with TPE were included; 36 (18.8%) had ADA < 40 IU/L with a mean ADA activity level of 20.9 (±9.2) IU/L. Patients with low ADA were older (75.3 vs. 62.0 years,p < 0.001) and had a lower mean lymphocyte percentage (47.6% vs. 69.9%,p < 0.001) than patients with high ADA. Patients in the low ADA group had a significantly higher mean SOFA score (2.31 vs. 0.68,p < 0.001), and patients with organ dysfunction were significantly more common in the low ADA group (p < 0.001). Patients with 2 or ≥ 3 organ dysfunctions constituted 19.4 and 13.9% of the patients in the low ADA group, whereas they constituted 7.1 and 1.3% of the patients in the high ADA group (p < 0.001). Multivariate logistic regression analyses showed that older age (odds ratio = 1.030, 95% confidence interval 1.002–1.060,p = 0.038) and a higher SOFA score (odds ratio = 1.598, 95% confidence interval 1.239–2.060,p < 0.001) were significantly associated with low ADA activity in patients with TPE.Conclusions: ADA activity can be low in patients with TPE who are elderly, critically ill, and exhibit multiorgan failure. Low ADA activity cannot completely exclude the diagnosis of TPE, and physicians should exercise caution when interpreting pleural fluid exams.

Background/Aim: Cancer cells are distinct in terms of glutamine dependence. Here we investigated the different susceptibility of glutamine-independent and glutamine-dependent non-small cell lung cancer (NSCLC) to treatment with tumor necrosis factor receptor-associated protein 1 (TRAP1) inhibitor gamitrinib-triphenylphosphonium (G-TPP). Materials and Methods: Cell viability and proliferation under glutamine deprivation and G-TPP treatment were determined by the MTT and colony-formation assays. Protein and mRNA expression were determined by western blot and quantitative polymerase chain reaction. Colorimetric-based assay was performed to check for glutamine synthetase (GS) activity. Results: NSCLC cells showed diverse adaptation under glutamine-depleted condition and were categorized into glutamine-independent and glutamine-dependent cells. Treatment with G-TPP particularly increased GS activity and induced cell death due to energy shortage indicated by phosphorylated AMP-activated protein kinase (AMPK) in glutamine-dependent cells. Conclusion: This finding provides better understanding of TRAP1-mediated glutamine metabolism through GS activity, and evidence that TRAP1 could be a promising therapeutic target for glutamine-addicted cancer.

Spirometry is regarded as the only effective method for detecting pulmonary function test (PFT) indices. In this study, a novel impedance pulmonary function measurement system (IPFS) is developed for directly assessing PFT indices. IPFS can obtain high resolution values and remove motion artifacts through real-time base impedance feedback. Feedback enables the detection of PFT indices using only both hands for convenience. IPFS showed no differences in the sitting, supine, and standing postures during the measurements, indicating that patient posture has no effect on IPFS. Mean distance analysis showed good agreement between the volume and flow signal of IPFS (p < 0.05). PFT indices were detected in subjects to differentiate a chronic obstructive pulmonary disease (COPD) patient group from a normal group. The forced vital capacity (FVC), forced expiratory volume in the first second (FEV₁), FEV_1/FVC, and peak expiratory flow (PEF) in the COPD group were lower than those in the normal group by IPFS (p < 0.05). IPFS is therefore suitable for evaluating pulmonary function in normal and COPD patients. Moreover, IPFS could be useful for periodic monitoring of existing patients diagnosed with obstructive lung disease.

Background: In chronic obstructive pulmonary disease (COPD), inhaled corticosteroids (ICSs) are recommended for use by patients with frequent exacerbations and blood eosinophilia. However, ICSs are often inappropriately prescribed and overused. COPD studies have reported an increased risk of tuberculosis among ICS users. This study aimed to compare the risk of tuberculosis according to the different ICS components. Methods: This study was conducted using a nationwide, population-based cohort. Patients newly diagnosed with COPD between 2005 and 2018, and treated with either fluticasone propionate or budesonide, were selected. The patients were followed up until the development of tuberculosis. Results: After propensity score matching, 16,514 fluticasone propionate and 16,514 budesonide users were identified. The incidence rate of tuberculosis per 100,000 person-years was 274.73 for fluticasone propionate and 214.18 for budesonide. The hazard ratio of tuberculosis in fluticasone propionate compared with budesonide was 1.28 (95% confidence interval 1.05–1.60). The risk of tuberculosis for fluticasone propionate increased with higher ICS cumulative doses: 1.01 (0.69–1.48), 1.16 (0.74–1.81), 1.25 (0.79–1.97), and 1.82 (1.27–2.62) from the lowest to highest quartiles, respectively. Conclusion: Fluticasone propionate is associated with a higher risk of tuberculosis than budesonide. ICS components can differently affect the risk of tuberculosis in patients with COPD.