Association between oxygen saturation level during bronchoscopy and post-bronchoscopy adverse events: a retrospective cohort study.

BACKGROUND: Flexible bronchoscopy is widely used to diagnose and treat various respiratory diseases. However, caution is warranted for post-bronchoscopy adverse events. Although desaturation frequently occurs during bronchoscopy, its clinical impact and the optimal oxygen saturation level during the procedure remain unclear. This study aimed to investigate whether the percutaneous oxygen saturation (SpO2) level during bronchoscopy is associated with the development of post-bronchoscopy respiratory adverse events. METHODS: In this single-center retrospective cohort study conducted from March 2020 to February 2021, 569 patients were classified into high or low oxygen saturation groups based on the SpO2 level during bronchoscopy. The primary outcome was post-bronchoscopy respiratory adverse events, and secondary outcomes were other post-bronchoscopy adverse events and clinical outcomes. RESULTS: Among 569 patients, 458 and 111 patients were classified into the high oxygen saturation (SpO2 > 96%) and low oxygen saturation (SpO2 ≤ 94%) groups, respectively. After propensity score matching, the low oxygen saturation group had more post-bronchoscopy respiratory and febrile adverse events than the high oxygen saturation group. In the multivariable regression analysis, low SpO2 level during bronchoscopy was an independent risk factor for post-bronchoscopy respiratory adverse events (odds ratio = 3.16 [95% confidence interval 1.37-7.30]). In the low oxygen saturation group, the high-risk subgroups for post-bronchoscopy respiratory adverse events were the elderly, women, current smokers, and patients with chronic obstructive pulmonary disease or acute decompensated heart failure before bronchoscopy. There was no significant difference in the length of hospital stay, intensive care unit admission, or mortality between the high and low oxygen saturation groups. CONCLUSIONS: Close monitoring is recommended for patients with SpO2 ≤ 94% during bronchoscopy due to the increased risk of respiratory adverse events after the procedure.

The Impact of Erosive Reflux Esophagitis on the Decline of Lung Function in the General Population.

BACKGROUND: The impact of reflux esophagitis on the decline of lung function has been rarely reported. This study was performed to evaluate the association between erosive reflux esophagitis and lung function changes. METHODS: We included patients with normal lung function who underwent esophagogastroduodenoscopy for health screening from a health screening center. Patients with persistent erosive reflux esophagitis on two discrete endoscopic examinations were designated as the erosive reflux esophagitis group. We also selected patients without erosive reflux esophagitis and matched them 1:4 with patients from the erosive reflux esophagitis group. We estimated annual forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) changes from baseline and compared these estimates by the linear mixed regression model. We also estimated the biannual incidence of chronic obstructive pulmonary disease (COPD). RESULTS: In total, 1,050 patients (210 patients with erosive reflux esophagitis, and 840 matched controls) were included. The median follow-up duration for spirometry was six years. In patients with erosive reflux esophagitis, mild reflux esophagitis (A grade) was most common (165 patients, 78.6%). The adjusted annual FEV1 change in patients with erosive reflux esophagitis was -51.8 mL/yr, while it decreased by 46.8 mL/yr in controls (P = 0.270). The adjusted annual FVC decline was similar between the two groups (-55.8 vs. -50.5 mL/yr, P = 0.215). The estimated COPD incidence during the follow-up period was not different between the erosive reflux esophagitis and control groups. CONCLUSION: In patients with normal lung function, the presence of erosive reflux esophagitis did not affect the annual declines in FEV1 or FVC.

Interstitial Lung Abnormalities and the Clinical Course in Patients With COPD.

BACKGROUND: The presence and progression of interstitial lung abnormalities (ILAs) is known to be associated with a decline of lung function and increased risk of mortality. RESEARCH QUESTION: We aimed to elucidate the clinical course according to ILAs in patients with COPD. STUDY DESIGN AND METHODS: A retrospective study was conducted between January 2013 and December 2018 of COPD patients who underwent chest CT imaging and longitudinal pulmonary function tests. We evaluated radiologic findings, history of acute exacerbations of COPD, and lung function changes during the longitudinal follow-up. RESULTS: Of 363 patients with COPD, 44 and 103 patients had equivocal and definite ILAs, respectively. Patients with ILAs were significantly older and had lower FEV1 and FVC than patients without ILAs. During the mean follow-up period of 5.2 years, ILAs were associated significantly with the annual incidence of moderate to severe acute exacerbation of COPD (ß ± SD, 0.38 ± 0.12; P = .002) and with the risk of frequent exacerbation (adjusted OR, 2.03; P = .045). Patients with progressive ILAs showed a significantly higher rate of annual decline in FEV1 and FVC than those showing no change in, or improved, ILAs. INTERPRETATION: ILAs were associated significantly with moderate to severe acute exacerbation in patients with COPD, and the progression of ILAs was associated with an accelerated decline in lung function.

Clinical implication and risk factor of pneumonia development in mild coronavirus disease 2019 patients.

BACKGROUND/AIMS: Although a majority of coronavirus disease 2019 (COVID-19) cases were characterized as mild, data assessing the development of pneumonia in mild COVID-19 patients are limited. We aimed to examine the effect of pneumonia development on the clinical course of mild COVID-19 in hospitalized patients. METHODS: A retrospective cohort study was conducted via medical record review between February 25, 2020 and April 11, 2020 at a single center. The impact of pneumonia development on the time to viral clearance in mild COVID-19 patients was evaluated. Risk factors associated with the development of pneumonia were also identified. RESULTS: Chest radiographs revealed the development of pneumonia in 26.8% of mild COVID-19 patients. The time to pneumonia development was a median of 8.0 days from the onset of symptoms and 3.5 days after hospital admission. A multivariate analysis for predicting pneumonia development identified age ≥ 65 years (odds ratio [OR], 3.15; 95% confidence interval [CI], 1.14 to 8.73), cough (OR, 2.18; 95% CI, 1.29 to 3.68), dyspnea (OR, 3.58; 95% CI, 1.10 to 11.69), and diarrhea (OR, 2.69; 95% CI, 1.51 to 4.78) as significant variables. The time to negative conversion was longer in mild COVID-19 patients who developed pneumonia (23.6 days vs. 18.4 days, p = 0.003). In Kaplan-Meier estimation and multivariate Cox regression analyses, newly developed pneumonia was significantly related with delayed time to negative conversion (log-rank test, p = 0.02; hazard ratio, 2.90; 95% CI, 1.06 to 7.97). CONCLUSION: The development of pneumonia delayed viral clearance in patients with mild COVID-19. Elderly patients or those suffering from diarrhea should be closely monitored, given the increased risk of developing pneumonia.

Chest computed tomography scan as an initial diagnostic method for tuberculosis infection detected by mass screening.

BACKGROUND/AIMS: We assessed the diagnostic yield of chest computed tomography (CT) as an initial diagnostic method for patients with a tuberculosis (TB) infection detected by mass screening in a country with an intermediate TB burden. METHODS: A retrospective study was conducted on patients with TB infection detected by mass screening performed between January 2015 and March 2018. The patients were classified according to whether they had a chest X-ray (CXR) or CT scan as an initial diagnostic test to exclude active TB. RESULTS: Of 542 patients with TB infection detected by mass screening, 222 and 320 were initially examined by CXR and CT, respectively; the two modalities showed no significant difference in rate of detection of patients with active TB (0.9% and 2.5%, respectively; p = 0.110). However, chest CT was associated with further invasive tests using bronchoscopy and respiratory specimens, and significantly increased the frequency of hospital visits. CONCLUSION: Chest CT was not supported as an initial diagnostic method to rule out active TB in patients with a TB infection detected by mass screening in a country with an intermediate TB burden.

A Genome-Wide Association Study in Early COPD: Identification of One Major Susceptibility Loci.

Background: Identifying the genetic basis of airflow limitation is one of the most interesting issues for understanding chronic obstructive pulmonary disease (COPD) pathophysiology. Several studies have shown that some genetic variants associated with COPD have been identified in genome-wide association study (GWAS), especially in patients with moderate to severe COPD; genetic susceptibility for airflow limitation in the early COPD phase has not been widely studied. Objective: We investigated the genetic variants in early COPD. Methods: The present study analyzed Gene-environment interaction and phenotype (GENIE) cohort that included participants who received health screening examination. The association between single nucleotide polymorphism (SNP) and susceptibility to early COPD (FEV1 predicted ≥50% and FEV1/FVC <0.7) was tested. Results: A total of 130 patients with early COPD and 3478 controls (1700 ever smokers and 1778 never smokers) were recruited. When compared with the total controls, certain SNPs (rs2818103, rs875033, rs9354627, rs34552148) on chromosome 6 were included at the top of our list (p= 5.6 × 10-7 ~9.6 × 10-6) although they did not reach genome-wide significance. When compared with the never smoker controls, two SNPs (rs2857210, rs2621419) of the HLA-DQB2 gene class were persistently associated with susceptibility to early COPD. Conclusion: Certain SNPs located on chromosome 6 or the HLA-DQB2 gene were the top-scoring SNPs for the association with susceptibility to early COPD in the Korean GENIE cohort.

The clinical impact of drug-induced hepatotoxicity on anti-tuberculosis therapy: a case control study.

BACKGROUND: There are limited data available on whether drug-induced hepatotoxicity (DIH) affects the clinical outcomes of tuberculosis (TB) treatment. We explored the effects of DIH on the clinical course and outcomes of pulmonary TB. METHODS: In this retrospective cohort study, we included patients with culture-proven pulmonary TB treated in a tertiary hospital from 2013 to 2016. DIH was defined as proposed by the official American Thoracic Society statement. We compared the clinical outcomes of DIH and non-DIH patients. RESULTS: Between January 1, 2013 and December 31, 2016, a total of 168 TB patients were included, and 20 (11.9%) were diagnosed with DIH. These patients were significantly older, had a higher Charlson Comorbidity Index score, exhibited more chronic liver disease, included more chronic alcoholics, and had a lower body mass index than non-DIH patients. We found no significant differences between DIH and non-DIH patients in the 2-month sputum culture conversion rate, the time to sputum culture conversion, treatment outcomes, or total treatment duration. However, the ratio of treatment interruption time to total treatment duration and the proportion of hepatotonic users were significantly higher among DIH patients. CONCLUSION: DIH development during TB treatment does not significantly affect the clinical outcomes of pulmonary TB. However, treatment interruption caused by DIH may increase the risks of future relapse and acquired resistance. Further study is needed.

Thromboembolism in Mycobacterium tuberculosis Infection: Analysis and Literature Review.

BACKGROUND: Tuberculosis is associated with hypercoagulation; however, there are few reports of cases thromboembolism and tuberculosis at the same time in the real world. The purpose of this study was to report the incidence and clinical course of thromboembolism in patients diagnosed with tuberculosis. MATERIALS AND METHODS: We retrospectively analyzed the data of patients who were diagnosed with both tuberculosis and thromboembolism including pulmonary thromboembolism (PTE) or deep vein thrombosis (DVT) at Seoul National University Boramae Medical Center from January 2000 through March 2015. RESULTS: Among the 7905 tuberculosis patients, 49 (0.6%) exhibited PTE, DVT, or both at or after the time of tuberculosis diagnosis. All patients treated for tuberculosis started with isoniazid, ethambutol, rifampicin, and pyrazinamide. Eight patients were switched to treatment with second-line medication because of resistance or adverse events. About half of the patients (n = 21, 44.7%) had thrombosis at the time of tuberculosis diagnosis. Of 48 patients treated for thromboembolism, 36 received warfarin. A total of 20 patients improved symptom caused by thrombosis, and 10 patients were confirmed cure by image study such as computed tomography or doppler ultrasonography. Eight patients who were treated with warfarin had persistent thrombosis. Five patients (10.2%) experienced major bleeding that required hospitalization. All of these bleeding events were associated with warfarin therapy. CONCLUSIONS: Careful attention to PTE/DVT is needed at the time of diagnosis of tuberculosis and during anti-tuberculosis therapy. Warfarin therapy administered with anti-tuberculosis medication requires frequent monitoring to prevent major bleeding.

Long-Term Follow-Up of Ground-Glass Nodules After 5 Years of Stability.

INTRODUCTION: Small ground-glass nodules (GGNs) or those with an indeterminate risk on low-dose computed tomography (LDCT) of the chest are recommended at 5-year follow-up, but the rationale for follow-up beyond 5 years is unclear. METHODS: An observational study was conducted to investigate the natural course of GGNs that had been stable for 5 years by LDCT over 10 years. All eligible GGNs were detected during regular health checkups. Baseline characteristics were compared between GGNs with and without growth. Risk factors for GGN growth were evaluated. RESULTS: A total of 208 GGNs were detected in 160 participants. GGN growth was identified in 27 (13.0%) GGNs during a follow-up of 136 months on LDCT scans. In approximately 95% of these GGNs, the initial size was less than 6 mm, with 3.2 mm of growth over 8.5 years. Biopsies were performed in 3 of 27 GGNs, revealing adenocarcinoma. In 8 of 27 cases, GGN growth preceded the development of a new solid component. In a multivariate analysis, bubble lucency (p = 0.001), a history of cancer other than lung cancer (p = 0.036), and development of a new solid component (p < 0.001) were significant risk factors for GGN growth. CONCLUSIONS: GGNs should not be ignored, even when smaller than 6 mm and stable for 5 years, especially when a new solid component appears during follow-up.

Comparison of clinical characteristics and outcomes between homeless and non-homeless patients admitted to intensive care units: An observational propensity-matched cohort study in Korea.

PURPOSE: To compare clinical characteristics and outcomes between critically ill homeless and non-homeless patients admitted to the intensive care unit (ICU) in a Korea. MATERIALS AND METHODS: We retrospectively analyzed the medical charts of homeless and non-homeless patients admitted to ICU at Seoul Boramae Medical Center between January 2012 and December 2017. Patients were selected using 1: 2 propensity score matching including age, sex, and type of ICU and multivariate analyses were performed to determine risk factors for hospital and ICU mortality. RESULTS: 56 homeless and 112 non-homeless matched patients were analyzed. The homeless patients were younger, included more men, and exhibited significantly higher readmission and ER admission rates. Although hospital and ICU mortality rates were similar between two groups, the homeless patients were significantly less likely to have family or substitute decision-makers and generally died after cardiopulmonary resuscitation. Adjusted multivariate analysis showed that homelessness was not an independent predictor of ICU or hospital mortality. The length of ICU stay was comparable between groups. CONCLUSIONS: In Korea, ICU-admitted homeless patients are well managed without differences in terms of organ support quality and exhibit the same prognosis as non-homeless patients. However, the quality of end-of-life care for homeless patients remains poor.

The effect of metformin on culture conversion in tuberculosis patients with diabetes mellitus.

BACKGROUND/AIMS: Patients with diabetes mellitus (DM) and tuberculosis (TB) have increased morbidity and a high risk of treatment failure or recurrence. It is important to manage both diseases simultaneously. Among anti-diabetic drugs, metformin inhibits intracellular growth of mycobacteria. Therefore, we examined the effects of metformin on TB treatment, especially in patients with DM. METHODS: This retrospective cohort study included patients with culture-positive pulmonary TB diagnosed between 2011 and 2012. The primary study outcome was sputum culture conversion after 2 months of treatment. RESULTS: Of 499 patients diagnosed with culture-positive pulmonary TB, 105 (21%) had DM at diagnosis. Among them, 62 (59.5%) were treated with metformin. Baseline characteristics, except for the presence of chronic renal disease, were not significantly different between the metformin and non-metformin groups. Metformin treatment had no significant effect on sputum culture conversion (p = 0.60) and recurrence within 1 year after TB treatment completion (p = 0.39). However, metformin improved the sputum culture conversion rate in patients with cavitary pulmonary TB, who have higher bacterial loads (odds ratio, 10.8; 95% confidence interval, 1.22 to 95.63). CONCLUSION: Among cavitary pulmonary TB patients with DM, metformin can be an effective adjunctive anti-TB agent to improve sputum culture conversion after 2 months of treatment.

Effect of perioperative systemic steroid treatment on patients with obstructive lung disease undergoing elective abdominal surgery.

INTRODUCTION: Chronic obstructive pulmonary disease is an independent risk factor of postoperative pulmonary complications (PPCs). It is unknown whether a perioperative systemic corticosteroid would be beneficial in patients with obstructive airway disease. OBJECTIVES: The present study was conducted to determine the effect of a perioperative systemic corticosteroid on PPCs in patients who showed airway obstruction in preoperative spirometry. METHODS: Retrospective medical record reviews were performed on records from January 2010 to December 2011 in a referral hospital. We analyzed the data of patients who were referred to pulmonologists before elective abdominal surgery and had a prebronchodilator FEV1/FVC of <70%. We compared the PPCs between the steroid group and the non-steroid group. RESULTS: A total of 270 patients were referred to pulmonologists and, of these, 86 had a FEV1/FVC of <70% in the preoperative spirometry. In the 30 patients in the steroid group, the mean FEV1 was 52.2% and half of these had previously used a bronchodilator. Use of a perioperative systemic corticosteroid was significantly associated with reduced incidence of PPCs in the multivariate logistic regression with adjustment by propensity score (adjusted odds ratio = 0.036, 95% confidence interval [CI] = 0.003-0.505; P = 0.014). CONCLUSION: In our retrospective study we showed that those treated with steroids had better outcomes. However, future prospective and randomized controlled trials are needed.

Risk factors for pulmonary arterial hypertension in patients with tuberculosis-destroyed lungs and their clinical characteristics compared with patients with chronic obstructive pulmonary disease.

BACKGROUND AND OBJECTIVE: There are limited data on pulmonary arterial hypertension (PAH) in patients with tuberculosis-destroyed lung (TDL), a sequela of pulmonary tuberculosis. We identified the risk factors for PAH and their effects on acute exacerbation and mortality in patients with TDL, as well as the clinical differences in patients with chronic obstructive pulmonary disease (COPD) and PAH. METHODS: A retrospective cohort study was conducted from 2010 through 2015 in a municipal referral hospital in South Korea. PAH was defined when echocardiographic pulmonary arterial pressure (PAP) was >40 mmHg. The clinical features and course of TDL patients with or without PAH were evaluated and differences between patients with COPD and PAH were analyzed. RESULTS: Among the 195 patients with TDL, echocardiographic data were available in 53 patients, and their mean PAP was 50.72±23.99 mmHg. The PAH group (n=37) had a smaller lung volume (forced vital capacity % predicted, 51.55% vs 72.37%, P<0.001) and more extensively destroyed lungs (3.27 lobes vs 2 lobes, P<0.001) than those in the non-PAH group (n=16). A higher PAP was significantly correlated with a higher frequency of acute exacerbation (r=0.32, P=0.02). Multivariate analyses did not reveal any significant risk factors contributing to PAH in patients with TDL. Compared to COPD patients with PAH, TDL patients with PAH have smaller lung volume but a less severe airflow limitation. Tricuspid regurgitation and a D-shaped left ventricle during diastole were more frequently observed in TDL patients. The risk of exacerbation was not different between patients with PAH in COPD and TDL. CONCLUSION: PAH in patients with TDL was associated with severity of lung destruction but risk of exacerbation and mortality did not significantly differ between patients with PAH and without PAH.

Effect of Prophylactic Use of Silymarin on Anti-tuberculosis Drugs Induced Hepatotoxicity.

BACKGROUND: The first line of anti-tuberculosis (TB) drugs are the most effective standard of drugs for TB. However, the use of these drugs is associated with hepatotoxicity. Silymarin has protective effects against hepatotoxicity of anti-TB drugs in animal models. This study aims to investigate the protective effect of silymarin on hepatotoxicity caused by anti-TB drugs. METHODS: This is a prospective, randomized, double-blind and placebo-controlled study. Patients were eligible if they were 20 years of age or order and started the first-line anti-tuberculosis drugs. Eligible patients were randomized for receiving silymarin or a placebo for the first 4 weeks. The primary outcome was the proportion of patients who showed elevated serum liver enzymes more than 3 times the upper normal limit (UNL) or total bilirubin (TBil) > 2× UNL within the first 8 weeks of anti-TB treatment. RESULTS: We enrolled a total of 121 patients who silymarin or a placebo to start their anti-TB treatment, for the first 8 weeks. The proportions of elevated serum liver enzymes more than 3 times of UNL at week 2, week 4, and week 8 did not show any significant difference between the silymarin and placebo groups, at 0% versus 3.6% (p>0.999); 4.4% versus 3.6% (p>0.999); and 8.7% versus 10.8% (p=0.630), respectively. However, patients with TBil >2× ULN at week 8 were significantly low in the silymarin group (0% versus 8.7%, p=0.043). CONCLUSION: Our findings did not show silymarin had any significant preventive effect on the hepatotoxicity of anti-TB drugs.

Chronic obstructive pulmonary disease is independently associated with hypertension in men: A survey design analysis using nationwide survey data.

Although studies have shown that chronic obstructive pulmonary disease (COPD) and hypertension are linked as comorbidities, it remains unclear whether COPD is independently associated with the risk of hypertension or is caused by common risk factors such as age and smoking. The objective of this study was to investigate the relationship between COPD and hypertension by using nationally representative data.This cross-sectional study analyzed data from the Korea National Health and Nutrition Examination Survey V conducted during 2010 to 2012. Hypertension was defined as a mean systolic blood pressure ≥ 140 mm Hg and/or a diastolic blood pressure ≥ 90 mm Hg, or current consumption of antihypertensive medications. A diagnosis of COPD was defined as a smoking history of at least 10 pack-years with airflow limitation on spirometry. Multivariate logistic regression was performed to investigate the independent association between COPD and hypertension after adjusting for covariates. Survey design analyses were conducted for all analyses.Among 4043 men (aged ≥ 40 years) who underwent spirometry, 2190 (54.2%) had hypertension. Even after adjusting for age, body mass index, smoking status, diabetes, metabolic syndrome, and stroke, COPD was independently associated with hypertension (adjusted odds ratio, 1.71; 95% confidence interval, 1.37-2.13; P < .001). Adjusted pulse pressure significantly increased as the ratio of forced expiratory volume in 1 s (FEV1) to forced vital capacity and FEV1 decreased.COPD is independently associated with hypertension, and this could explain the link between the risk of cardiovascular diseases and COPD.

The effect of obesity on patients with mild chronic obstructive pulmonary disease: results from KNHANES 2010 to 2012.

PURPOSE: A low body mass index has been associated with high mortalities in patients with chronic obstructive pulmonary disease (COPD), and studies reveal that obesity aggravates the clinical effects of COPD. We investigated the impact of obesity on patients newly identified with COPD. PATIENTS AND METHODS: This population-based, cross-sectional study, used data from the Korea National Health and Nutrition Examination Survey (KNHANES) conducted from 2010 to 2012. Through analyses of data from this survey, we compared concurrent comorbid diseases, symptoms, and lung functions between an obese and nonobese group of patients with COPD. RESULTS: In total, 618 participants were diagnosed with COPD and the average forced expired volume in 1 s (FEV1) was 79.47%±0.69%. Of the total, 30.5% of the subjects were categorized into an obese group. Subjects in the obese group were likely to have metabolic syndrome (P<0.001), hypertension (P=0.02), and a higher number of comorbidities compared to the nonobese group (2.3±0.1 vs 2.0±0.1, P=0.02). In addition, subjects in the obese group showed a lower forced vital capacity (FVC) than subjects in the nonobese group, even after adjusting for covariates (average FVC%, 89.32±1.26 vs 92.52%±0.72%, P=0.037). There were no significant differences in the adjusted FEV1% and adjusted FEV1/FVC between the groups. CONCLUSIONS: Among subjects newly identified with mild COPD, participants in the obese group had more comorbid conditions and showed a lower FVC compared with subjects in the nonobese group, even after adjustment of covariates. These findings show that a combination of obesity and COPD may be a severe phenotype; therefore, early attention should be paid to obesity for the management of COPD patients.

Prediction of Anthracofibrosis Based on Clinico-Radiographic Findings.

PURPOSE: Because anthracofibrosis (AF) is associated with tuberculosis (TB), detection of AF is clinically relevant in Korea, a TB endemic region. We thus sought to develop and validate a predictive model for AF using clinical radiographic data. MATERIALS AND METHODS: Between January 1, 2008 and March 31, 2014, 3849 adult patients who underwent bronchoscopies were retrospectively included from an observational registry. We dichotomized patients based on the presence (n=167) or absence (n=242) of AF. After analyzing their clinico-radiographic characteristics, a logistic prediction model was developed. An area under the curve (AUC) was drawn using the weighted score in logistic regression model. To evaluate the degree of overfitting of the predictive model, a 5-fold cross-validation procedure was performed. RESULTS: In multivariate logistic regression, clinical findings such as age >70 years, female gender, active TB, and computed tomography findings including atelectasis, stenosis, bronchial wall thickening, enlarged and calcified lymph nodes were significant diagnostic predictors for AF. The weighed score had an AUC of 0.939 [95% confidence interval (CI)=0.911-0.960], similar to the AUC obtained from internal validation (AUC=0.926, 95% CI=0.896-0.949). CONCLUSION: The prediction model may be helpful for predicting AF based only on clinical and radiographic findings. However, further external validation is necessary.

The regional association between bronchiectasis and lung cancer in chest CT.

BACKGROUND: Limited studies have examined the association between lung cancer and bronchiectasis (BE). This study evaluated the regional association between BE and lung cancer by analyzing the lobar location of lung cancer in patients with underlying BE. METHODS: This clustered multi-level study enrolled patients who had underlying BE and were newly diagnosed with lung cancer between January 1, 2010 and May 30, 2013 in two referral hospitals in South Korea. By analyzing the presence of lung cancer and underlying BE as event variables at the level of lung lobes on chest computed tomography (CT), we evaluated the association of BE and lung cancer by the locations of the diseases. RESULTS: Eighty-one patients with BE and combined lung cancer were enrolled. Within 486 lung lobes of the patients, combined BE and lung cancer in the same lobe was found in 11 lobes (2.3 %). Using the general estimating equation assuming BE as a risk factor of lung cancer, the results indicated that the prevalence of lung cancer was significantly lower in the lobes with pre-existing BE (ß = -1.09, p-value = 0.001). CONCLUSIONS: Regionally, pre-existing BE was associated with a lower risk of the occurrence of lung cancer in the same lobe.

Discordance between MTB/RIF and Real-Time Tuberculosis-Specific Polymerase Chain Reaction Assay in Bronchial Washing Specimen and Its Clinical Implications.

The prevalence and clinical implications of discordance between Xpert MTB/RIF assays and the AdvanSure TB/NTM real-time polymerase chain reaction (PCR) for bronchial washing specimens have not been studied in pulmonary TB (PTB) patients. The discordant proportion and its clinical impact were evaluated in 320 patients from the bronchoscopy registry whose bronchial washing specimens were tested simultaneously with Xpert MTB/RIF and the TB/NTM PCR assay for three years, and the accuracy of the assays, including the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were studied. The clinical risk factors for discordance and false positivity of assays were also studied. Among 130 patients who were clinically diagnosed with PTB, 64 patients showed positive acid-fast bacilli culture results, 56 patients showed positive results in molecular methods and clinician diagnosed PTB without results of microbiology in 10 patients. The sensitivity, specificity, PPV, and NPV were 80.0%, 98.95%, 98.1%, and 87.9%, respectively, for Xpert MTB/RIF and 81.5%, 92.6%, 88.3%, and 88.0%, respectively, for TB/NTM PCR. The discordant proportion was 16.9% and was higher in culture-negative PTB compared to culture-confirmed PTB (24.3% vs. 9.4%, p = 0.024). However, there were no significant differences in the clinical characteristics, regardless of the discordance. The diagnostic yield increased with an additional assay (7.7% for Xpert MTB/RIF and 9.2% for TB/NTM PCR). False positivity was less common in patients tested with Xpert MTB/RIF (1.05% vs. 7.37%, p = 0.0035). No host-related risk factor for false positivity was identified. The Xpert MTB/RIF and TB/NTM PCR assay in bronchial washing specimens can improve the diagnostic yields for PTB, although there were considerable discordant results without any patient-related risk factors.