Development of a population pharmacokinetic model of pyrazinamide to guide personalized therapy: impacts of geriatric and diabetes mellitus on clearance.

Objectives: This study was performed to develop a population pharmacokinetic model of pyrazinamide for Korean tuberculosis (TB) patients and to explore and identify the influence of demographic and clinical factors, especially geriatric diabetes mellitus (DM), on the pharmacokinetics (PK) of pyrazinamide (PZA). Methods: PZA concentrations at random post-dose points, demographic characteristics, and clinical information were collected in a multicenter prospective TB cohort study from 18 hospitals in Korea. Data obtained from 610 TB patients were divided into training and test datasets at a 4:1 ratio. A population PK model was developed using a nonlinear mixed-effects method. Results: A one-compartment model with allometric scaling for body size effect adequately described the PK of PZA. Geriatric patients with DM (age >70 years) were identified as a significant covariate, increasing the apparent clearance of PZA by 30% (geriatric patients with DM: 5.73 L/h; others: 4.50 L/h), thereby decreasing the area under the concentration-time curve from 0 to 24 h by a similar degree compared with other patients (geriatric patients with DM: 99.87 µg h/mL; others: 132.3 µg h/mL). Our model was externally evaluated using the test set and provided better predictive performance compared with the previously published model. Conclusion: The established population PK model sufficiently described the PK of PZA in Korean TB patients. Our model will be useful in therapeutic drug monitoring to provide dose optimization of PZA, particularly for geriatric patients with DM and TB.

Current status and trends of pulmonary rehabilitation in South Korea: National level data analysis using Health Insurance Review and Assessment Service (HIRA) database from 2016 to 2018.

In South Korea, there are few studies to understand the current status of pulmonary rehabilitation in clinical practice and develop it. This study aimed to assess the current status and annual changes in the number and pattern of prescriptions for pulmonary rehabilitation before and after its insurance coverage. The trends of pulmonary rehabilitation before and after its insurance coverage commencement were evaluated using the data of 24,380 patients during the 3-year period from 2016 to 2018 that were archived by the National Health Information Database of the Health Insurance Review and Assessment Service in South Korea. The annual total number of patients who received pulmonary rehabilitation was stratified by the type of prescription, sex, age, type of insurance, medical institution, and region. In addition, the frequencies of pulmonary rehabilitation for various diagnoses were investigated using the major codes of the Korean Standard Classification of Disease. The patients who received pulmonary rehabilitation increased by approximately 2 times from 5936 in 2016 (before insurance coverage) to 10,474 in 2019. Before 2017, most patients underwent simple pulmonary rehabilitation coded as MM290. However, since the insurance coverage of rehabilitation exercise for pulmonary disease (MM440), the proportions of patients receiving them increased. Men underwent pulmonary rehabilitation more often than women, and >70% of the patients were aged >60 years. Most patients received pulmonary rehabilitation at tertiary hospitals in Seoul. In 2016, pulmonary rehabilitation was prescribed more frequently for cerebral infarction; after 2017, it was prescribed more frequently for lung cancer. This study summarized the current status and trends of pulmonary rehabilitation in South Korea before and after National Health Insurance Service coverage, which commenced on January 1, 2017. A significant increase in the number of pulmonary rehabilitations was confirmed after the insurance coverage.

Peak oxygen uptake and respiratory muscle performance in patients with chronic obstructive pulmonary disease: Clinical findings and implications.

The maximal oxygen uptake (VO2max) is the gold standard measure of aerobic exercise capacity and is an important outcome measure in patients with chronic obstructive pulmonary disease (COPD). And respiratory muscle performance is also an important functional parameter for COPD patients. In addition to the traditional respiratory muscle strength test, the Test of Incremental Respiratory Endurance has recently been introduced and validated in patients with COPD. However, the relationship between VO2 and respiratory muscle performance in COPD is not well understood. Therefore, this study investigated the correlations among VO2 and respiratory muscle performance and other functional markers in COPD. A total of 32 patients with COPD were enrolled. All study participants underwent the following assessments: cardiopulmonary exercise test, pulmonary function test, respiratory muscle strength test, peripheral muscle strength test, and bioelectrical impedance analysis. When comparing VO2peak and respiratory muscle parameters, the sustained maximal inspiratory pressure (SMIP) was the only factor with a significant relationship with VO2peak. Among other functional parameters, the forced expiratory volume in one second (FEV1) showed the strongest correlation with VO2peak. It was followed by phase angle values of lower limbs, leg extension peak torque, age, and total skeletal muscle mass. When comparing respiratory muscle performance with other functional parameters, the SMIP showed the strongest correlation with hand grip strength, followed by peak cough flow, forced vital capacity, maximal inspiratory pressure, and FEV1. The results showed that the SMIP was more significantly correlated with VO2peak than the static measurement of respiratory muscle strength. This suggests that TIRE may be a useful assessment tool for patients with COPD. Additionally, FEV1 and other functional markers were significantly correlated with VO2peak, suggesting that various parameters may be used to evaluate aerobic power indirectly.

Clinical outcomes of hyperprogression based on volumetry in non-small cell lung cancer after immune checkpoint inhibitor treatment.

BACKGROUND: Hyperprogressive disease (HPD) is a novel pattern of the treatment course after immune checkpoint inhibitor (ICI) therapy in patients with non-small cell lung cancer (NSCLC). This study aimed to investigate the clinical characteristics, outcomes, and associated factors of HPD using a semiautomatic volume measurement. METHODS: This retrospective study enrolled patients with recurrent and/or metastatic NSCLC treated with ICIs between January 2015 and August 2019 at eight tertiary centers in Korea. HPD was defined according to the tumor growth kinetics and time to treatment failure. Tumor volume was measured using a semiautomatic software. RESULTS: A total of 219 NSCLC patients with 35 HPD by volumetric measurement (HPDv) (15.9%) were enrolled. The median duration of overall survival (OS) and OS after ICI treatment (ICI-OS) were 34.5 and 18.4 months, respectively. HPDv patients had significantly worse progression-free survival (PFS) than progressive disease patients without HPDv (1.16 vs. 1.82 months, p-value <0.001). ICI-OS did not significantly differ between patients with HPDv and those without HPDv (2.66 vs. 5.4 months, p = 0.105). PD-L1 expression lower than 50%, more than three metastatic sites, neutrophil-to-lymphocyte ratio equal to or higher than 3.3, and hemoglobin level lower than 10 were found to be associated with HPDv. CONCLUSIONS: There is no standardized definition of HPD. However, defining HPD in NSCLC patients treated with ICI using a semiautomatic volume measurement software is feasible.

Acute respiratory distress syndrome caused by carbon monoxide poisoning and inhalation injury recovered after extracorporeal membrane oxygenation along with direct hemoperfusion with polymyxin B-immobilized fiber column: a case report.

BACKGROUND: Inhalation injury from smoke or chemical products and carbon monoxide poisoning are major causes of death in burn patients from fire accidents. Respiratory tract injuries from inhalation injury and carbon monoxide poisoning can lead to acute respiratory distress syndrome and cytokine storm syndrome. In the case of acute respiratory failure needing mechanical ventilation accompanied by cytokine storm, mortality is high and immediate adequate treatment at the emergency department is very important. CASE PRESENTATION: This report describes a case of acute respiratory distress syndrome and cytokine storm followed by carbon monoxide poisoning in a 34-year-old Korean male patient who was in a house fire, and was successfully treated by extracorporeal membrane oxygenation and direct hemoperfusion with polymyxin B-immobilized fiber column at emergency department. CONCLUSIONS: To prevent mortality in acute respiratory distress syndrome with cytokine storm from inhalation injury and to promote a better prognosis, we suggest that early implication of extracorporeal membranous oxygenation along with direct hemoperfusion with polymyxin B-immobilized fiber column even at the emergency department should be considered.

Prognostic Factors of Second-line Immune Checkpoint Inhibitors in Patients With Advanced-stage Non-Small Cell Lung Cancer: A Multicenter, Retrospective Study.

OBJECTIVES: Immune checkpoint inhibitors (ICIs) targeting the programmed cell death receptor-1 and its ligand have achieved impressive success in treating patients with advanced-stage non-small cell lung cancer (NSCLC) after failed first-line cytotoxic chemotherapy. However, knowledge on clinical biomarkers that could help select patients who will respond well to second-line ICI therapy is limited. PATIENTS AND METHODS: Medical records of patients with NSCLC treated with first-line platinum-based chemotherapy and subsequent second-line ICI were collected from 6 medical centers between January 2018 and June 2020. Clinical information, pathologic variables, and radiologic findings of the data collected were reviewed. The patients were followed up until the date of the last visit, the death of any cause, or the end of data recording (December 31, 2020). RESULTS: A total of 181 patients with NSCLC were treated with second-line ICI following first-line platinum-based doublet chemotherapy. The median progression-free survival was 2.0 months (interquartile range, 1.0 to 5.5 mo), and the median overall survival was 12.0 months (interquartile range, 6.0 to 20.0 mo). Low body mass index (BMI) was independently associated with progression-free survival (odds ratio [OR], 0.826; 95% confidence interval [CI], 0.723-0.945; P=0.005). Similarly, a low BMI (OR, 0.839; 95% CI, 0.740-0.952; P=0.005) and a high number of metastatic organs (OR, 1.682; 95% CI, 1.156-2.448; P=0.007) were independently associated with the overall survival after second-line ICI therapy. CONCLUSION: BMI and the number of metastatic sites were significantly associated with second-line ICI therapy outcomes in patients with NSCLC receiving first-line platinum-based chemotherapy.

Unilateral pleuroparenchymal fibroelastosis as a rare form of idiopathic interstitial pneumonia: A case report.

BACKGROUND: Pleuroparenchymal fibroelastosis (PPFE) is a rare idiopathic interstitial pneumonia characterized by predominantly upper lobe involvement with pleural fibrosis and subjacent parenchymal fibrosis. Recently, there have been increasing reports of PPFE, and PPFE might coexist with other interstitial lung diseases in the lower lobe and upper lobe. However, cases of unilateral PPFE are scarce. CASE SUMMARY: A 75-year-old Korean male presented to our hospital with chronic dry cough and exertional dyspnea. The patient's symptoms started 6 mo previously and had been gradually worsening. At the time of presentation, he felt dyspnea when walking at his own pace. Radiologic findings suggested PPFE, but the lesion was localized in the upper lobe of the right lung. After multidisciplinary discussion, a transbronchial lung biopsy in the right upper lobe revealed collapsed alveoli with parenchymal fibroelastosis, and elastic van Gieson staining demonstrated septal elastosis with intra-alveolar collagenosis, which met the histopathologic criteria of definite PPFE. After multidisciplinary discussion in an experienced interstitial lung disease center, we confirmed the diagnosis of unilateral PPFE. Furthermore, we confirmed the progression of PPFE on radiologic findings during the follow-up period. CONCLUSION: Clinicians should consider PPFE, even in cases with unilateral, predominantly upper lung involvement in interstitial lung disease patients through multidisciplinary discussion.

The Association Between Eosinophil Variability Patterns and the Efficacy of Inhaled Corticosteroids in Stable COPD Patients.

Introduction: Blood eosinophils are a predictive marker for the use of inhaled corticosteroids (ICS). However, there is concern over whether a single measure of blood eosinophils is sufficient for outlining a treatment plan. Here, we evaluated the association between variability in blood eosinophils and the effects of ICS in stable COPD cohorts. Methods: COPD patients in the Korean COPD Subtype Study and the Seoul National University Airway Registry from 2011 to 2018 were analyzed. Based on blood eosinophils at baseline and at 1-year follow-up, the patients were classified into four groups with 250/µL as a cutoff value: consistently high (CH), consistently low (CL), variably increasing (VI), and variably decreasing (VD). We compared rates of acute exacerbations (AEs) according to ICS use in each group after calibration of severity using propensity score matching. Results: Of 2,221 COPD patients, 618 were analyzed and a total of 125 (20%), 355 (57%), 63 (10%), and 75 (12%) patients were classified into the CH, CL, VI, and VD groups, respectively. After calibration, we found that ICS users tended to have a lower AE rate in the CH group (RR 0.41, 95% CI 0.21-0.74) and VI group (RR 0.45, 95% CI 0.22-0.88), but not in the CL group (RR 1.42, 95% CI 1.08-1.89) and VD group (RR 1.71, 95% CI 1.00-2.96). Conclusion: More than one-fifth of patients had an inconsistent blood eosinophil level after the 1-year follow-up, and the AE-COPD rate according to ICS differed based on variability in eosinophils. Regular follow-up of blood eosinophils is required for COPD patients.

Usefulness of impulse oscillometry for the assessment of bronchodilator response in elderly patients with chronic obstructive airway disease.

BACKGROUND: Impulse oscillometry (IOS) is a noninvasive and convenient technique to measure both airway resistance and reactance. This study aimed to evaluate whether IOS can be used to measure bronchodilator response (BDR) in elderly patients with asthma and chronic obstructive pulmonary disease (COPD) and also describe the difference between asthma and COPD. METHODS: Seventy patients (30 and 40 with asthma and COPD, respectively) over 65 years of age were enrolled. IOS and spirometry measurements were obtained before and after bronchodilator administration. Correlation analysis was used to compare the percentage changes in spirometry and IOS parameters after bronchodilator administration between the asthma and COPD groups. RESULTS: The changes in IOS parameters after bronchodilator administration were strongly correlated with changes in forced expiratory volume at 1 second (FEV1) and forced expiratory flow at 25-75% (FEF25-75). However, the percentage changes in IOS parameters failed to discriminate between the asthma and COPD groups. Receiver operating characteristic curve (ROC) analysis of resistance at 5 and 20 Hz (R5-20) at the best cutoff (-15.4% change) showed both high sensitivity and specificity for BDR. CONCLUSIONS: IOS serves as a reliable and useful technique for identifying BDR in elderly patients with chronic obstructive airway disease. There was a difference in IOS parameters between the asthma and COPD groups; however, it was difficult to distinguish between both diseases. Further larger studies are required to investigate the real implications of using IOS in the clinical practice.

Lipoid pneumonitis in a patient with an accidental ingestion of kerosene successfully treated with bronchoscopic segmental lavage and systemic steroid: Case report.

RATIONALE: Standard treatment of lipoid pneumonitis remains unclear. This study reports a case of kerosene pneumonitis successfully treated with systemic steroid and segmental bronchoalveolar lavage (BAL). PATIENT CONCERNS: A 30-year-old woman referred to our hospital because of worsening of respiratory symptoms and fever despite antibiotic therapy following accidental ingestion of kerosene. She had no underlying disease. DIAGNOSES: Chest CT scan showed necrotic consolidation, ground glass opacity (GGO), bronchial wall thickening in the right middle/lower lobe (RML/RLL) and right pleural effusion. The lipoid pneumonitis was confirmed by identification of a lipid laden macrophage in bronchoalveolar lavage fluid. INTERVENTIONS: The patient was treated with systemic corticosteroid and segmental BAL. OUTCOMES: The patient's symptoms rapidly improved after treatment and she was discharged one week after admission. A follow-up CT scan a week after discharge revealed marked resolution of consolidation. No recurrence was reported for 8 months. LESSONS: This is the first case of kerosene pneumonitis successfully treated with systemic steroid and bronchoscopic segmental lavage therapy in Korea. Very few cases have been reported worldwide.

Comparison of Preferred Bite Sites Between Mites and Ticks on Humans in Korea.

Identification of mite and tick bite sites provides important clinical information. The predominant mite species in Korea associated with scrub typhus are Leptotrombidium pallidum and Leptotrombidium scutellare The most abundant tick species is Haemaphysalis longicornis To date, there has been no comparative study on preferred bite sites between mites and ticks in humans. This study included a review of medical records and a field study. For mite bite sites, eschars were checked on 506 patients with scrub typhus, confirmed by indirect immunofluorescence assay or nested polymerase chain reaction on the 56-kDa type-specific antigen gene of Orientia tsutsugamushi Tick bite sites were identified and marked on a diagram for 91 patients who experienced tick bites within the previous year through a field epidemiological investigation. The mite and tick bite sites in Koreans were compared. The most frequently observed mite bite sites were the anterior chest, including the axillae (29.1%) and the abdominal region, including the inguinal area (26.1%). Tick bite sites were most frequent on the lower extremities (33.0%), followed by the abdominal region, including the inguinal area (26.4%), and upper extremities (26.4%). The distribution was significantly different between mite and tick bite sites (P < 0.001). There was a statistically significant difference in the mite bite (P = 0.001), but not tick bite sites (P = 0.985), between men and women. This is the first report on the differences between tick and mite bite sites, and may help clinicians reach a rapid diagnosis of mite- or tick-borne infection.

Erratum: Tracheal Involvement in Crohn Disease: the First Case in Korea.

[This corrects the article on p. 202 in vol. 49, PMID: 26879553.].

Tracheal Involvement in Crohn Disease: the First Case in Korea.

Respiratory involvement in Crohn disease (CD) is rare condition with only about a dozen reported cases. We report the first case of CD with tracheal involvement in Korea. An 18-year-old woman with CD was hospitalized because of coughing, dyspnea, and fever sustained for 3 weeks. Because she had stridor in her neck, we performed computed tomography of the neck, which showed circumferential wall thickening of the larynx and hypopharynx. Bronchoscopy revealed mucosal irregularity, ulceration, and exudates debris in the proximal trachea, and bronchial biopsy revealed chronic inflammation with granulation tissue. Based on these findings, we suspected CD with tracheal involvement and began administering intravenous methylprednisolone at 1 mg/kg per day, after which her symptoms and bronchoscopic findings improved.

Two ß-strands of RAGE participate in the recognition and transport of amyloid-ß peptide across the blood brain barrier.

Amyloid-ß (Aß) peptide is central to the development of brain pathology in Alzheimer disease (AD) patients. Association with receptors for advanced glycation end-products (RAGE) enables the transport of Aß peptide from circulating blood to human brain, and also causes the activation of the NF-κB signaling pathway. Here we show that two ß-strands of RAGE participate in the interaction with Aß peptide. Serial deletion analysis of the RAGE V domain indicates that the third and eighth ß-strands are required for interaction with Aß peptide. Site-directed mutagenesis of amino acids located in the third and eighth ß-strands abolish the interaction of RAGE with Aß peptide. Wild-type RAGE activates the NF-κB signaling pathway in response to Aß peptide treatment, while a RAGE mutant defective in Aß binding does not. Furthermore, use of peptide for the third ß-strand or a RAGE monoclonal antibody that targets the RAGE-Aß interaction interface inhibited transport of the Aß peptide across the blood brain barrier in a mice model. These results provide information crucial to the development of RAGE-derived therapeutic reagents for Alzheimer disease.

Incidental diagnosis of the unicuspid aortic valve with ascending aortic aneurysm in an asymptomatic adult.

The unicuspid aortic valve is an extremely rare congenital anomaly. It usually presents with aortic stenosis and/or aortic regurgitation. Other cardiovascular complications, such as aortic dilatation and left ventricular hypertrophy can accompany it. Herein, we present a case report of a 50-year-old asymptomatic male patient with unicuspid aortic valve, complicated by ascending aortic aneurysm.

Two-year clinical outcome after abciximab-coated stent implantation in patients with coronary artery disease.

BACKGROUND: Despite abciximab-coated stents having an inhibitory effect on coronary artery restenosis, the medium-term clinical outcome is unknown. METHODS AND RESULTS: This prospective, randomized study compared the effects of the abciximab-coated stent, which was implanted in 95 patients, with those of control bare metal stents (BMS) implanted in 93 patients for de novo coronary lesions. Stent implantation was performed without any complications associated with the procedure. The 6-month intravascular ultrasound analysis showed that the area of neointimal hyperplasia was significantly smaller in the abciximab-coated stent group compared with the control stent group (+2.0+/-1.6 mm(2) vs +3.4+/-1.7 mm(2), P=0.001). However, at 2-year clinical follow up, there were no statistically significant differences in the incidences of total major adverse cardiac events (16% vs 24%, P=0.19) and cardiac death (0% vs 1.1%, P=0.3), target vessel revascularization (16% vs 21%, P=0.4) or non-fatal myocardial infarction (0% vs 2.3%, P=0.16) in the abciximab-coated stent group compared with the control stent group. CONCLUSIONS: Although abciximab-coated stents are safe and inhibit neointimal hyperplasia, they have no superiority over BMS in 2-year clinical outcome.

Acute and subacute stent thrombosis in a patient with clopidogrel resistance: a case report.

Drug-eluting stents (DES) are considered the treatment of choice for most patients with obstructive coronary artery disease when percutaneous intervention (PCI) is feasible. However, stent thrombosis seems to occur more frequently with DES and occasionally is associated with resistance to anti-platelet drugs. We have experienced a case of recurrent stent thrombosis in a patient with clopidogrel resistance. A 63-year-old female patient suffered from acute myocardial infarction and underwent successful PCI of the left anterior descending coronary artery (LAD) with two DESs. She was found to be hyporesponsive to clopidogrel and was treated with triple anti-platelet therapy (aspirin 100 mg, clopidogrel 75 mg, and cilostazol 200 mg daily). Three days after discharge, she developed chest pain and was again taken to the cardiac catheterization laboratory, where coronary angiography (CAG) showed total occlusion of the mid-LAD where the stent had been placed. After intravenous administration of a glycoprotein IIb/IIIa inhibitor, balloon angioplasty was performed, resulting in Thrombolysis In Myocardial Infarction (TIMI) III antegrade flow. The next day, however, she complained of severe chest pain, and the electrocardiogram showed marked ST-segment elevation in V1-V6, I, and aVL with complete right bundle branch block. Emergent CAG revealed total occlusion of the proximal LAD due to stent thrombosis. She was successfully treated with balloon angioplasty and was discharged with triple anti-platelet therapy.

Association of HLA class II genes with idiopathic pulmonary arterial hypertension in Koreans.

The aim of this study was to compare the frequency of the HLA-DRB1 and HLA-DQB1 alleles in Korean patients with idiopathic pulmonary arterial hypertension (IPAH) and in normal controls and to determine any association that may exist between clinical characteristics of IPAH and specific HLA alleles. IPAH patients seen between October 1998 and September 2001 were retrospectively assessed, and 19 patients and 193 controls were HLA typed at the HLA-DRB1 and DQB1 loci. Clinical characteristics and hemodynamic parameters were reviewed. The patients with IPAH had a significantly higher frequency of the HLA-DRB1*0406 allele (18% vs. 6%, p = 0.004) and the HLA-DQB1*0302 allele (24% vs. 12%, p = 0.034), as well as a significantly higher frequency of haplotype DRB1*0406-DQB1*0302 (p = 0.0006). All 6 patients with haplotype DRB1*0406-DQB1*0302 (H+ group) were women, compared with 8 of the 13 patients lacking the DRB1*0406-DQB1*0302 haplotype (H- group), but without statistical significance. Three of 19 patients showed a positive short-term hemodynamic response to NO inhalation, all 3 of whom had the DRB1*0406-DQB1*0302 haplotype. There were no other significant differences in clinical characteristics and hemodynamic parameters between the H+ and H- groups. We conclude from this study that the HLA-DRB1*0406-DQB1*0302 haplotype is associated with IPAH in Korean patients. These results suggest that certain clinical characteristics of IPAH may be controlled in part by patients' HLA alleles.