Background: Global Lung Function Initiative (GLI)-2012 reference equation is currently suggested for interpretation of spirometry results and a new local reference equation has been developed in South Korea. However, lung function profiles according to the different reference equations and their clinical relevance have not been identified in chronic obstructive pulmonary disease (COPD) patients. Methods: Our cross-sectional study evaluated Choi’s, Korean National Health and National Examination Survey (KNHANES)-VI, and GLI-2012 reference equations. We estimated the percentages of predictive forced expiratory volume in one second (FEV 1) and airflow limitation severity according to reference equations and analyzed their associations with patient reported outcomes (PROs): COPD assessment test (CAT) score, St. George's Respiratory Questionnaire for COPD patients (SGRQ-C) score, and six minute walk distance (6MWD). Results: In the eligible 2,180 COPD patients, lower predicted values of FEV 1 and forced vital capacity (FVC) were found in GLI-2012 compared to Choi's and KNHANES-VI equations.GLI-2012 equation resulted in a lower proportion of patients being classified as FEV 1 < 80% or FVC < 80% compared to the other equations. However, the Z-scores of FEV 1 and FVC were similar between the KNHANES-VI and GLI-2012 equations. Three reference equations exhibited significant associations between FEV 1 (%) and patient-reported outcomes (CAT score, SGRQ-C score, and 6MWD). Conclusion GLI-2012 reference equation may not accurately reflect FEV 1 (%) in the Korean population, but the Z-score using GLI-2012 equation can be a viable option for assessing FEV 1 and airflow limitation in COPD patients. Similar to the other two equations, the GLI-2012 equation demonstrated significant associations with PROs.

Objectives: Gastrointestinal cytomegalovirus (CMV) disease is a major contributor to mortality in immunocompromised patients. Few studies have discussed upper gastrointestinal CMV (UGICMV) disease in immunocompetent patients. We compared the clinical outcomes of UGI-CMV between immunocompromised and immunocompetent patients. Methods: This retrospective study included patients with UGI-CMV disease from five tertiary hospitals across Korea (2010– 2022). Patients’ clinical data and outcomes were recorded. Results: UGI-CMV was diagnosed in 54 patients; 27 (50.0%) had esophageal, 24 (44.4%) had gastric, and 3 patients (5.6%) had duodenal involvement. Patients’ median age was 64 years (interquartile range 53–75 years), and the most common comorbidities included hypertension (57.4%) and diabetes (38.9%). The predominant symptom was abdominal pain (46.3%), and the most common endoscopic finding was ulcers (70.4%). Antiviral treatment was administered to 31 patients, and 23 patients underwent observation without treatment. We investigated 32 immunocompromised (59.3%) and 22 immunocompetent (40.7%) patients and observed no intergroup differences in comorbidities and in laboratory and endoscopic findings. Immunocompromised patients had longer length of hospitalization (median 46.2 days vs. 20.0 days, p=0.001). However, treatment outcomes, including the need for intensive care unit admission and mortality did not significantly differ. The overall mortality rate was 13.0%; one patient from the immunocompromised group died of UGI-CMV disease. The treatment success rate was higher in immunocompromised patients who received antiviral therapy (p=0.011). Conclusions UGI-CMV disease is not uncommon in immunocompetent patients, although symptoms are milder than those in immunocompromised patients. Our findings emphasize the importance of clinical vigilance for accurate diagnosis of CMV infection, particularly in susceptible symptomatic patients and highlight the need for active antiviral treatment for management of immunocompromised patients.

Background: Asthma and chronic obstructive pulmonary disease (COPD) are airway diseases with similar clinical manifestations, despite differences in pathophysiology. AsthmaCOPD overlap (ACO) is a condition characterized by overlapping clinical features of both diseases. There have been few reports regarding the prevalence of ACO in COPD and severe asthma cohorts. ACO is heterogeneous; patients can be classified on the basis of phenotype differences. This study was performed to analyze the prevalence of ACO in COPD and severe asthma cohorts. In addition, this study compared baseline characteristics among ACO patients according to phenotype. Methods: Patients with COPD were prospectively enrolled into the Korean COPD subgroup study (KOCOSS) cohort. Patients with severe asthma were prospectively enrolled into the Korean Severe Asthma Registry (KoSAR). ACO was defined in accordance with the updated Spanish criteria. In the COPD cohort, ACO was defined as bronchodilator response (BDR) ≥ 15% and ≥ 400 mL from baseline or blood eosinophil count (BEC) ≥ 300 cells/μL. In the severe asthma cohort, ACO was defined as age ≥ 35 years, smoking ≥ 10 pack-years, and postbronchodilator forced expiratory volume in 1 s/forced vital capacity < 0.7. Patients with ACO were divided into four groups according to smoking history (threshold: 20 pack-years) and BEC (threshold: 300 cells/μL). Results: The prevalence of ACO significantly differed between the COPD and severe asthma cohorts (19.8% [365/1,839] vs. 12.5% [104/832], respectively; P < 0.001). The percentage of patients in each group was as follows: group A (light smoker with high BEC) – 9.1%; group B (light smoker with low BEC) – 3.7%; group C (moderate to heavy smoker with high BEC) – 73.8%; and group D (moderate to heavy smoker with low BEC) – 13.4%. Moderate to heavy smoker with high BEC group was oldest, and showed weak BDR response. Age, sex, BDR, comorbidities, and medications significantly differed among the four groups. Conclusion The prevalence of ACO differed between COPD and severe asthma cohorts. ACO patients can be classified into four phenotype groups, such that each phenotype exhibits distinct characteristics.

Gastroesophageal reflux disease (GERD) is a condition in which gastric contents regurgitate into the esophagus or beyond, resulting in either troublesome symptoms or complications. GERD is heterogeneous in terms of varied manifestations, test findings, and treatment responsiveness. GERD diagnosis can be established with symptomatology, pathology, or physiology. Recently the Lyon consensus defined the “proven GERD” with concrete evidence for reflux, including advanced grade erosive esophagitis (Los Angeles classification grades C and or D esophagitis), long-segment Barrett’s mucosa or peptic strictures on endoscopy or distal esophageal acid exposure time > 6% on 24-hour ambulatory pH-impedance monitoring. However, some Asian researchers have different opinions on whether the same standards should be applied to the Asian population. The prevalence of GERD is increasing in Asia. The present evidence-based guidelines were developed using a systematic review and meta-analysis approach. In GERD with typical symptoms, a proton pump inhibitor test can be recommended as a sensitive, cost-effective, and practical test for GERD diagnosis. Based on a meta-analysis of 19 estimated acid-exposure time values in Asians, the reference range upper limit for esophageal acid exposure time was 3.2% (95% confidence interval 2.7-3.9%) in the Asian countries. Esophageal manometry and novel impedance measurements, including mucosal impedance and a post-reflux swallow-induced peristaltic wave, are promising in discrimination of GERD among different reflux phenotypes, thus increasing its diagnostic yield. We also propose a long-term strategy of evidence-based GERD treatment with proton pump inhibitors and other drugs.

Gastroesophageal reflux disease (GERD) is a condition in which gastric contents regurgitate into the esophagus or beyond, resulting in either troublesome symptoms or complications. GERD is heterogeneous in terms of varied manifestations, test findings, and treatment responsiveness. GERD diagnosis can be established with symptomatology, pathology, or physiology. Recently the Lyon consensus defined the “proven GERD” with concrete evidence for reflux, including advanced grade erosive esophagitis (Los Angeles classification grades C and or D esophagitis), long-segment Barrett’s mucosa or peptic strictures on endoscopy or distal esophageal acid exposure time > 6% on 24-hour ambulatory pH-impedance monitoring. However, some Asian researchers have different opinions on whether the same standards should be applied to the Asian population. The prevalence of GERD is increasing in Asia. The present evidence-based guidelines were developed using a systematic review and meta-analysis approach. In GERD with typical symptoms, a proton pump inhibitor test can be recommended as a sensitive, cost-effective, and practical test for GERD diagnosis.Based on a meta-analysis of 19 estimated acid-exposure time values in Asians, the reference range upper limit for esophageal acid exposure time was 3.2% (95% confidence interval, 2.7-3.9%) in the Asian countries. Esophageal manometry and novel impedance measurements, including mucosal impedance and a post-reflux swallow-induced peristaltic wave, are promising in discrimination of GERD among different reflux phenotypes, thus increasing its diagnostic yield. We also propose a long-term strategy of evidence-based GERD treatment with proton pump inhibitors and other drugs.

Gastroesophageal reflux disease (GERD) is a condition in which gastric contents regurgitate into the esophagus or beyond, resulting in either troublesome symptoms or complications. GERD is heterogeneous in terms of varied manifestations, test findings, and treatment responsiveness. GERD diagnosis can be established with symptomatology, pathology, or physiology. Recently the Lyon consensus defined the “proven GERD” with concrete evidence for reflux, including advanced grade erosive esophagitis (Los Angeles classification grades C and or D esophagitis), long-segment Barrett’s mucosa or peptic strictures on endoscopy or distal esophageal acid exposure time > 6% on 24-hour ambulatory pH-impedance monitoring. However, some Asian researchers have different opinions on whether the same standards should be applied to the Asian population. The prevalence of GERD is increasing in Asia. The present evidence-based guidelines were developed using a systematic review and meta-analysis approach. In GERD with typical symptoms, a proton pump inhibitor test can be recommended as a sensitive, cost-effective, and practical test for GERD diagnosis.Based on a meta-analysis of 19 estimated acid-exposure time values in Asians, the reference range upper limit for esophageal acid exposure time was 3.2% (95% confidence interval, 2.7-3.9%) in the Asian countries. Esophageal manometry and novel impedance measurements, including mucosal impedance and a post-reflux swallow-induced peristaltic wave, are promising in discrimination of GERD among different reflux phenotypes, thus increasing its diagnostic yield. We also propose a long-term strategy of evidence-based GERD treatment with proton pump inhibitors and other drugs.

The flaviviruses are small single-stranded RNA viruses that are typically transmitted by mosquitoes or tick vectors and are etiological agents of acute zoonotic infections. The viruses are found around the world and account for significant cases of human diseases. We investigated population of culicine mosquitoes in central region of Korean Peninsula, Incheon Metropolitan City and Hwaseong-si. Aedes vexans nipponii was the most frequently collected mosquitoes (56.5%), followed by Ochlerotatus dorsalis (23.6%), Anopheles spp. (10.9%), and Culex pipiens complex (5.9%). In rural regions of Hwaseong, Aedes vexans nipponii was the highest population (62.9%), followed by Ochlerotatus dorsalis (23.9%) and Anopheles spp. (12.0%). In another rural region of Incheon (habitat of migratory birds), Culex pipiens complex was the highest population (31.4%), followed by Ochlerotatus dorsalis (30.5%), and Aedes vexans vexans (27.5%). Culex pipiens complex was the predominant species in the urban region (84.7%). Culicine mosquitoes were identified at the species level, pooled up to 30 mosquitoes each, and tested for flaviviral RNA using the SYBR Green-based RT-PCR and confirmed by cDNA sequencing. Three of the assayed 2,683 pools (989 pools without Anopheles spp.) were positive for Culex flaviviruses, an insect-specific virus, from Culex pipiens pallens collected at the habitats for migratory birds in Incheon. The maximum likelihood estimation (the estimated number) for Culex pipiens pallens positive for Culex flavivirus was 25. Although viruses responsible for mosquito-borne diseases were not identified, we encourage intensified monitoring and long-term surveillance of both vector and viruses in the interest of global public health.

Background: There is little data regarding types of idiopathic premature ventricular complex (PVC) according to heart rate dependence. Methods: One hundred and sixty-eight patients with idiopathic PVC were enrolled in this study. Evaluation of the number of PVCs and total ventricular beats, and the density of PVC was done using 24 h Holter monitoring. Patients were divided into groups as having: fast rate-dependent (Group I), slow rate-dependent (Group II), and heart rateindependent PVC (Group III) based on the relationship between the number of hourly PVC and hourly heart rate. After ß-blocker medication, 24 h Holter monitoring was repeated. Results: Among the 168 subjects, 66 (39.3%) patients were in Group I, 18 (10.7%) in Group II, and 84 (50.0%) in Group III. There were no significant differences in the baseline number of PVCs and total ventricular beats, and the density of PVC among the three groups. The number of PVCs was significantly reduced in patients with Group I (14,030 ± 11,463 beats/day vs. 7401 ± 10,464 beats/day, p < 0.001), and total ventricular beat was significantly reduced in patients with Group I (109,223 ± 17,564 beats/day vs. 96,182 ± 15,594 beats/day, p < 0.001) and Group III (106,515 ± 13,468 beats/ day vs. 97,995 ± 12,960 beats/day, p < 0.001) after ß-blocker medication. The density of PVC was significantly reduced only in patients of Group I (12.9 ± 10.3% vs. 7.4 ± 10.3%, p = 0.001) after ß-blocker medication. Conclusions The type of PVC according to the heart rate dependence should be considered when treating idi‑ opathic PVC with ß-blockers.

Background: Tension pneumothorax on the contralateral lung during one-lung ventilation (OLV) can be life-threatening if not rapidly diagnosed and managed. However, diagnosis is often delayed because the classic signs of tension pneumothorax are similar to clinical manifestations commonly observed during OLV.Case: We report a case of contralateral tension pneumothorax in a patient undergoing right upper lobectomy during OLV. The patient suffered from sudden cardiac arrest and was assisted by extra-corporeal membrane oxygenation. Conclusions Contralateral pneumothorax during OLV is rare but can occur at any time. Therefore, anesthesiologists should consider this critical complication.

Rectal involvement by systemic lupus erythematosus (SLE) is quite rare. Approximately 14 cases have been reported worldwide, but only one with ischemic colitis has been reported in Korea. A 17-year-old female patient was hospitalized with abdominal pain and hematochezia. Sigmoidoscopy revealed only a simple rectal ulcer without ischemic colitis. cytomegalovirus and bacterial infections were excluded. A sigmoidoscopic rectal biopsy indicated a rectal invasion by SLE, but the patient showed an acute worsening conditions that did not respond to treatment. This paper reports a case of rectal ulcer that developed in SLE without ischemic colitis with a review of the relevant literature.
Abdominal Pain ; Adolescent ; Bacterial Infections ; Biopsy ; Colitis, Ischemic ; Cytomegalovirus ; Female ; Gastrointestinal Hemorrhage ; Humans ; Korea ; Lupus Erythematosus, Systemic ; Sigmoidoscopy ; Ulcer