Background: Chronic cough is a common symptom encountered by healthcare practitioners.The global prevalence of chronic cough is 9.6%, with a female predominance. The aim of our study is to reveal the sex differences in prevalence and severity of chronic cough in South Korea, stratified by age and etiology. Methods: This study included adult patients with chronic cough who were recruited from 19 respiratory centers in South Korea. Patients completed the cough numeric rating scale (NRS) and COugh Assessment Test (COAT) questionnaire to assess the severity and multidimensional impact of cough. Results: Among the 625 patients, 419 (67.0%) were females, with a male-to-female ratio of 1:2.03. The mean age was 49.4 years, and the median duration of cough was 12 weeks. The mean NRS and COAT scores were 5.5 ± 1.8 and 9.5 ± 3.6, respectively. Female patients were older (45.3 ± 15.4 vs. 51.6 ± 15.2, P < 0.001) and more likely to have asthma/cough variant asthma (CVA) (26.7% vs. 40.8%, P = 0.001) than male patients. There was no difference in the duration or severity of cough between sexes, regardless of the cause. The male-tofemale ratio was lower for upper airway cough syndrome (UACS), asthma/CVA, and gastroesophageal reflux disease (GERD), but not for eosinophilic bronchitis (EB) or unexplained cough. The mean age of female patients was higher in UACS and asthma/CVA, but not in EB, GERD, or unexplained cough. The majority (24.2%) fell within the age category of 50s. The proportion of females with cough increased with age, with a significant rise in the 50s, 60s, and 70–89 age groups. The severity of cough decreased in the 50s, 60s, and 70–89 age groups, with no significant sex differences within the same age group. Conclusion The sex disparities in prevalence and severity of cough varied significantly depending on the age category and etiology. Understanding the specific sex-based difference could enhance comprehension of cough-related pathophysiology and treatment strategies.

Isolated extramedullary relapse (EMR) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in acute myeloid leukemia (AML) is relatively rare and the clinical significance is still not well characterized, particularly in children. During or after chemotherapy, an uncommon event termed lineage switch, in which the lineage at onset of leukemia converts to another lineage at a later time, is observed in a subset of leukemia patients, but it is a rare event. We report a 10-year-old boy with isolated mediastinal EMR after allo-HSCT for AML who subsequently experienced BM relapse with the cell lineage switching from AML to T-cell acute lymphoblastic leukemia.

Objective: : Deep learning is a machine learning approach based on artificial neural network training, and object detection algorithm using deep learning is used as the most powerful tool in image analysis. We analyzed and evaluated the diagnostic performance of a deep learning algorithm to identify skull fractures in plain radiographic images and investigated its clinical applicability. Methods: : A total of 2026 plain radiographic images of the skull (fracture, 991; normal, 1035) were obtained from 741 patients. The RetinaNet architecture was used as a deep learning model. Precision, recall, and average precision were measured to evaluate the deep learning algorithm’s diagnostic performance. Results: : In ResNet-152, the average precision for intersection over union (IOU) 0.1, 0.3, and 0.5, were 0.7240, 0.6698, and 0.3687, respectively. When the intersection over union (IOU) and confidence threshold were 0.1, the precision was 0.7292, and the recall was 0.7650. When the IOU threshold was 0.1, and the confidence threshold was 0.6, the true and false rates were 82.9% and 17.1%, respectively. There were significant differences in the true/false and false-positive/false-negative ratios between the anteriorposterior, towne, and both lateral views (p=0.032 and p=0.003). Objects detected in false positives had vascular grooves and suture lines. In false negatives, the detection performance of the diastatic fractures, fractures crossing the suture line, and fractures around the vascular grooves and orbit was poor. Conclusion : The object detection algorithm applied with deep learning is expected to be a valuable tool in diagnosing skull fractures.

Background: Recent reports have suggested that pneumonitis is a rare complication following vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).However, its clinical features and outcomes are not well known. The aim of this study was to identify the clinical characteristics and outcomes of patients with vaccine-associated pneumonitis following vaccination against SARS-CoV-2. Methods: In this nationwide multicenter survey study, questionnaires were distributed to pulmonary physicians in referral hospitals. They were asked to report cases of development or exacerbation of interstitial lung disease (ILD) associated with the coronavirus disease 2019 vaccine. Vaccine-associated pneumonitis was defined as new pulmonary infiltrates documented on chest computed tomography within 4 weeks of vaccination and exclusion of other possible etiologies. Results: From the survey, 49 cases of vaccine-associated pneumonitis were identified between February 27 and October 30, 2021. After multidisciplinary discussion, 46 cases were analyzed. The median age was 66 years and 28 (61%) were male. The median interval between vaccination and respiratory symptoms was 5 days. There were 20 (43%), 17 (37%), and nine (19%) patients with newly identified pneumonitis, exacerbation of pre-diagnosed ILD, and undetermined pre-existing ILD, respectively. The administered vaccines were BNT162b2 and ChAdOx1 nCov-19/AZD1222 each in 21 patients followed by mRNA-1273 in three, and Ad26.COV2.S in one patient. Except for five patients with mild disease, 41 (89%) patients were treated with corticosteroid. Significant improvement was observed in 26 (57%) patients including four patients who did not receive treatment. However, ILD aggravated in 9 (20%) patients despite treatment. Mortality was observed in eight (17%) patients. Conclusion These results suggest pneumonitis as a potentially significant safety concern for vaccines against SARS-CoV-2. Clinical awareness and patient education are necessary for early recognition and prompt management. Additional research is warranted to identify the epidemiology and characterize the pathophysiology of vaccine-associated pneumonitis.

Background: In lung transplantation, human leukocyte antigen (HLA) compatibility is not included in the lung allocation score system or considered when placing donor allografts.However, HLA matching may affect the outcomes of lung transplantation. This study evaluated the current assessment status, prevalence, and effects of HLA crossmatching in lung transplantation in Korean patients using nationwide multicenter registry data. Methods: Two hundred and twenty patients who received lung transplantation at six tertiary hospitals in South Korea between March 2015 and December 2019 were retrospectively reviewed. Clinical data, including general demographic characteristics, primary diagnosis, and pretransplant status of the recipients and donors registered by the Korean Organ Transplant Registry, were retrospectively analyzed. Survival analysis was performed using the Kaplan-Meier method with log-rank tests. Results: Complement-dependent cytotoxic crossmatch (CDC-XM) was performed in 208 patients (94.5%) and flow cytometric crossmatch (flow-XM) was performed in 125 patients (56.8%). Among them, nine patients (4.1%) showed T cell- and/or B cell-positive crossmatches. The incidences of postoperative complications, including primary graft dysfunction, acute rejection, and chronic allograft dysfunction in positively crossmatched patients, were not significant compared with those in patients without mismatches.Moreover, Kaplan-Meier analyses showed poorer 1-year survival in patients with positive crossmatch according to CDC-XM (P < 0.001) and T lymphocyte XM (P = 0.002) than in patients without mismatches. Conclusion Positive CDC and T lymphocyte crossmatching results should be considered in the allocation of donor lungs. If unavailable, the result should be considered for postoperative management in lung transplantation.

Background: Pharmacogenomics is the study of how genetic mutations in patients affect their response to drugs. Pharmacogenomic studies aim to maximize drug effects and minimize adverse drug events. The Food and Drug Administration and the European Medicine Agency published guidelines for pharmacogenetics in 2005 and 2006, respectively; the Korean Ministry of Food and Drug Safety followed suit in 2015. Methods: This study analyzed pharmacogenomic information in the Korean Ministry of Food and Drug Safety’s integrated drug information system to evaluate whether domestic pharmaceutical products reflect the current research on pharmacogenomic differences. Results: In June 2020, the Korean pharmacogenomic database contained genomic data on 90 compounds. Of these, 45 compounds were classified as “Antineoplastic and immunomodulating agents.” The other 45 nonantineoplastic agents were in the following categories: Anti-infectives, Mental & behavior disorder, Hormone & metabolism related diseases, Cardiovascular system, Skin & subcutaneous tissue disease, Genito-urinary system and sex hormones, Blood and blood forming organs, Nervous system, Alimentary tract and metabolism, Musculo-skeletal system, and Other conditions including the respiratory system. In addition, 30 additives unrelated to the main ingredient were associated with genetic precautions. Conclusion This study showed that antineoplastic and immunomodulating agents accounted for half the drugs associated with pharmacogenetic information. For antitumor and immunomodulatory drugs, genomic tests were recommended depending on the indication; this was in contrast to genomic testing recommendations for non-antineoplastic medications. Genomic tests were rarely requested or recommended for non-antineoplastic medications because the relationships between genotype and efficacy among those drugs were relatively weak.

Cough is the most common respiratory symptom that can have various causes. It is a major clinical problem that can reduce a patient’s quality of life. Thus, clinical guidelines for the treatment of cough were established in 2014 by the cough guideline committee under the Korean Academy of Tuberculosis and Respiratory Diseases. From October 2018 to July 2020, cough guidelines were revised by members of the committee based on the first guidelines. The purpose of these guidelines is to help clinicians efficiently diagnose and treat patients with cough. This article highlights the recommendations and summary of the revised Korean cough guidelines. It includes a revised algorithm for the evaluation of acute, subacute, and chronic cough. For a chronic cough, upper airway cough syndrome (UACS), cough variant asthma (CVA), and gastroesophageal reflux disease (GERD) should be considered in differential diagnoses. If UACS is suspected, first-generation antihistamines and nasal decongestants can be used empirically. In cases with CVA, inhaled corticosteroids are recommended to improve cough. In patients with suspected chronic cough due to symptomatic GERD, proton pump inhibitors are recommended. Chronic bronchitis, bronchiectasis, bronchiolitis, lung cancer, aspiration, intake of angiotensin-converting enzyme inhibitor, intake of dipeptidyl peptidase-4 inhibitor, habitual cough, psychogenic cough, interstitial lung disease, environmental and occupational factors, tuberculosis, obstructive sleep apnea, peritoneal dialysis, and unexplained cough can also be considered as causes of a chronic cough. Chronic cough due to laryngeal dysfunction syndrome has been newly added to the guidelines.

Cough is the most common respiratory symptom that can have various causes. It is a major clinical problem that can reduce a patient’s quality of life. Thus, clinical guidelines for the treatment of cough were established in 2014 by the cough guideline committee under the Korean Academy of Tuberculosis and Respiratory Diseases. From October 2018 to July 2020, cough guidelines were revised by members of the committee based on the first guidelines. The purpose of these guidelines is to help clinicians efficiently diagnose and treat patients with cough. This article highlights the recommendations and summary of the revised Korean cough guidelines. It includes a revised algorithm for the evaluation of acute, subacute, and chronic cough. For a chronic cough, upper airway cough syndrome (UACS), cough variant asthma (CVA), and gastroesophageal reflux disease (GERD) should be considered in differential diagnoses. If UACS is suspected, first-generation antihistamines and nasal decongestants can be used empirically. In cases with CVA, inhaled corticosteroids are recommended to improve cough. In patients with suspected chronic cough due to symptomatic GERD, proton pump inhibitors are recommended. Chronic bronchitis, bronchiectasis, bronchiolitis, lung cancer, aspiration, intake of angiotensin-converting enzyme inhibitor, intake of dipeptidyl peptidase-4 inhibitor, habitual cough, psychogenic cough, interstitial lung disease, environmental and occupational factors, tuberculosis, obstructive sleep apnea, peritoneal dialysis, and unexplained cough can also be considered as causes of a chronic cough. Chronic cough due to laryngeal dysfunction syndrome has been newly added to the guidelines.

Purpose: Calcineurin inhibitor (CNI) use has improved lung transplantation outcomes. However, significant perioperative complications in patients receiving CNI can deteriorate the early course of lung transplantation. To date, there is no consensus regarding the optimal agent for the induction regimen after lung transplantation. We aimed to determine the efficacy of basiliximab induction with delayed CNI initiation in the prevention of acute complications without compromising immunosuppression in high-risk patients. Materials and Methods: Between January 2013 and December 2019, 236 patients at a single lung transplant center were retrospectively reviewed. Forty-one patients (17.4%) received basiliximab induction, and 195 patients (82.6%) received a routine triple-drug regimen without induction. The primary endpoint was postoperative acute kidney injury with several other postoperative outcomes as secondary end-points. Results: Preoperatively, the induction group had a higher proportion of patients who were admitted before transplantation (95.1% vs. 47.7%, p<0.001) and received intensive unit care (90.2% vs. 33.8%, p<0.001) and extracorporeal membrane oxygenation (ECMO) (87.8% vs. 20.0%, p<0.001) compared to the non-induction group. No significant differences were observed in the incidence of acute rejection between groups (p=0.657), although lower incidence of postoperative complications, including acute kidney injuries or culture-proven infections, were observed in the induction group. However, the differences were not statistically significant. A subgroup analysis of high-risk and preoperative ECMO support groups showed similar results. Conclusion Basiliximab induction with delayed CNI initiation for high-risk patients might decrease the incidence of perioperative complications, including acute renal failure, without increasing the risk of acute rejection.

Background: Pharmacogenomics is the study of how genetic mutations in patients affect their response to drugs. Pharmacogenomic studies aim to maximize drug effects and minimize adverse drug events. The Food and Drug Administration and the European Medicine Agency published guidelines for pharmacogenetics in 2005 and 2006, respectively; the Korean Ministry of Food and Drug Safety followed suit in 2015. Methods: This study analyzed pharmacogenomic information in the Korean Ministry of Food and Drug Safety’s integrated drug information system to evaluate whether domestic pharmaceutical products reflect the current research on pharmacogenomic differences. Results: In June 2020, the Korean pharmacogenomic database contained genomic data on 90 compounds. Of these, 45 compounds were classified as “Antineoplastic and immunomodulating agents.” The other 45 nonantineoplastic agents were in the following categories: Anti-infectives, Mental & behavior disorder, Hormone & metabolism related diseases, Cardiovascular system, Skin & subcutaneous tissue disease, Genito-urinary system and sex hormones, Blood and blood forming organs, Nervous system, Alimentary tract and metabolism, Musculo-skeletal system, and Other conditions including the respiratory system. In addition, 30 additives unrelated to the main ingredient were associated with genetic precautions. Conclusion This study showed that antineoplastic and immunomodulating agents accounted for half the drugs associated with pharmacogenetic information. For antitumor and immunomodulatory drugs, genomic tests were recommended depending on the indication; this was in contrast to genomic testing recommendations for non-antineoplastic medications. Genomic tests were rarely requested or recommended for non-antineoplastic medications because the relationships between genotype and efficacy among those drugs were relatively weak.