Hee Soon Chung

The diagnostic accuracy of tuberculosis real-time polymerase chain reaction analysis of computed tomography-guided bronchial wash samples

We evaluated the diagnostic accuracy of real-time polymerase chain reaction (RT-PCR) analysis of bronchoscopic wash specimens obtained using computed tomography (CT) guidance for diagnosis of pulmonary tuberculosis (TB) patients who were unable to produce sputum samples or were sputum smear-negative. Data from patients who had lesions likely to be pulmonary TB on CT images were analyzed retrospectively. Twenty-seven patients (23.1%) were diagnosed with definite pulmonary TB, and 72 patients (61.5%) were classified as not having TB. The sensitivity, specificity, positive predictive value, and negative predictive value of RT-PCR were 0.78 (95% CI, 0.57-0.91), 0.93 (95% CI, 0.84-0.97), 0.81 (95% CI, 0.60-0.93), and 0.92 (95% CI, 0.82-0.97), respectively. We concluded that most of the sputum-smear negative TB cases could be diagnosed microbiologically or ruled out rapidly and accurately by RT-PCR analysis of bronchial wash fluid.

The impact of lifestyle behaviors on the acquisition of pandemic (H1N1) influenza infection: a case-control study.

Purpose The purpose of this study was to evaluate the effects of lifestyle behaviors and health habits on the risk for acquiring pandemic influenza (H1N1) virus infection. Materials and Methods We conducted a case-control study in a secondary care hospital in South Korea between November 2009 and August 2010. We enrolled patients with H1N1 infection, as confirmed by a positive result of the real-time reverse transcriptase polymerase chain reaction assay; for each patient, we enrolled 4 age- and gender-matched controls with no history of H1N1 infection or severe acute respiratory illness during the H1N1 pandemic in South Korea (1:4 match). Results During the study period, 33 cases and 132 age- and gender-matched controls were enrolled. The case group had a higher percentage of current smokers (p<0.01), fewer subjects reporting regular physical activity (p=0.03), or regular vitamin supplementation (p<0.01), and more subjects reporting a higher annual incidence of the common cold (p=0.048) as compared to the control group. In the multivariable analysis, 2 factors were independently associated with the acquisition of H1N1 infection: current smoking [adjusted odds ratio (OR)=5.53; 95% confidence interval (CI), 1.60-19.16; p<0.01] and a higher annual incidence of the common cold (adjusted OR=1.24; 95% CI, 1.002-1.53; p=0.048). Conclusion A current smoking status and a history of frequent colds were associated with an increased risk of acquiring H1N1 infection.

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

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.

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.

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.

The regional association between bronchiectasis and lung cancer in chest CT

BackgroundLimited 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.MethodsThis 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.ResultsEighty-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 (2.3xa0%). 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 (βu2009=u2009−1.09, p-valueu2009=u20090.001).ConclusionsRegionally, pre-existing BE was associated with a lower risk of the occurrence of lung cancer in the same lobe.

Acceptability of Sputum Specimens for Diagnosing Pulmonary Tuberculosis

The evaluation of the quality of a sputum specimen prior to bacterial culture has been an accepted practice. However, optimal sputum criteria for pulmonary tuberculosis (TB) are not well established. We investigated indicators for sputum acceptability in tuberculosis cultures and acid-fast bacilli (AFB) smear. A post-hoc analysis of a randomized trial with 228 sputum specimens from 77 patients was conducted. In the trial, pulmonary TB suspects were requested for collecting three sputum specimens. We performed both TB study (AFB smear and M. tuberculosis culture) and Gram staining in each specimen. By using generalized estimating equations, the association between sputum characteristics and positive TB testings were analyzed. Although acceptable specimens for bacterial pneumonia showed higher TB-culture positive rates than unacceptable specimens (adjusted odds ratio [aOR]=1.66; 95% confidence interval [CI]=1.11-2.49), a specimen with ≥25 white blood cells/low-power field was the better predictor for positive M. tuberculosis cultures (aOR=2.30; 95% CI=1.48-3.58) and acid-fast bacilli smears (aOR=1.85; 95% CI=1.05-3.25). Sputum leukocytosis could be an indicator of sputum acceptability for diagnosing pulmonary tuberculosis. Graphical Abstract