Clinical and Laboratory Factors Associated with Symptom Development in Asymptomatic COVID-19 Patients at the Time of Diagnosis / 감염과화학요법

In preparation for the surge of coronavirus disease 2019 (COVID-19), it is crucial to allocate medical resources efficiently for distinguishing people who remain asymptomatic until the end of the disease. Between January 27, 2020, and April 21, 2020, 517 COVID-19 cases from 13 healthcare facilities in Gyeonggi province, Korea, were identified out of which the epidemiologic and clinical information of 66 asymptomatic patients at the time of diagnosis were analyzed retrospectively. An exposure-diagnosis interval within 7 days and abnormal aspartate aminotransferase levels were identified as characteristic symptom development in asymptomatic COVID-19 patients. If asymptomatic patients without these characteristics at the time of diagnosis could be differentiated early, more medical resources could be secured for mild or moderate cases in this COVID-19 surge.

Differences in Vancomycin Clearance between Trauma and Medical Intensive Care Unit Patients / 감염과화학요법

Background@#To identify the differences in the vancomycin pharmacokinetics between multiple trauma patients and medically ill patients in the intensive care unit (ICU) stratified by the use of continuous renal replacement therapy (CRRT), and the factors affecting vancomycin clearance (CLvan ). @*Materials and Methods@#All the included patients received at least three consecutive doses of vancomycin, then, therapeutic drug monitoring was conducted. Patients' serum vancomycin trough levels and other clinical variables were identified retrospectively. The vancomycin pharmacokinetics and associated factors were compared and analyzed between trauma ICU (TICU) and medical ICU (MICU) patients. @*Results@#In the non-dialyzed group, the CLvan was higher among the TICU patients than the MICU patients. However, in the continuous renal replacement therapy group, there was no significant difference in the CLvan between the multiple trauma and medically ill patients. The only factor associated with CLvan in the non-dialyzed group was creatinine clearance; none of the factors was associated with CLvan in the CRRT group. @*Conclusion@#In the case of non-dialyzed patients in the TICU, vancomycin dosages must be adjusted, depending on the patient's actual body weight changes. In the case of patients undergoing CRRT in both ICUs, vancomycin can be infused with fixed doses regardless of the patients' characteristics.

Methodology for Developing Evidence-Based Clinical Imaging Guidelines: Joint Recommendations by Korean Society of Radiology and National Evidence-Based Healthcare Collaborating Agency

This paper is a summary of the methodology including protocol used to develop evidence-based clinical imaging guidelines (CIGs) in Korea, led by the Korean Society of Radiology and the National Evidence-based Healthcare Collaborating Agency. This is the first protocol to reflect the process of developing diagnostic guidelines in Korea. The development protocol is largely divided into the following sections: set-up, process of adaptation, and finalization. The working group is composed of clinical imaging experts, and the developmental committee is composed of multidisciplinary experts to validate the methodology. The Korean CIGs will continue to develop based on this protocol, and these guidelines will act for decision supporting tools for clinicians as well as reduce medical radiation exposure.

Evaluation report on the causal association between humidifier disinfectants and lung injury / 한국역학회지

OBJECTIVES: As of November 2011, the Korean government recalled and banned humidifier disinfectants (HDs) from the market, because four case-control studies and one retrospective epidemiological study proved the association between HDs and lung injury of unknown cause. The report reviewed the causal role of HDs in lung injury based on scientific evidences. METHODS: A careful examination on the association between the HDs and lung injury was based on the criteria of causality inference by Hill and the US Surgeon General Expert Committee. RESULTS: We found that all the evidences on the causality fulfilled the criteria (strength of association, consistency, specificity, temporality, biologic gradient, plausibility, coherence, experiment, analogy, consideration of alternative explanations, and cessation of exposure), which proved the unknown cause lung injury reported in 2011 was caused by the HDs. In particular, there was no single reported case of lung injury since the ban in selling HDs in November 2011 as well as before the HDs were sold in markets. CONCLUSIONS: Although only a few epidemiological studies in Korea have evaluated the association between lung injury and the use of HDs, those studies contributed to proving the strong association between the use of the HDs and lung injury, based on scientific evidence.

An updated review of case–control studies of lung cancer and indoor radon-Is indoor radon the risk factor for lung cancer?

Lung cancer is a leading cause of cancer-related death in the world. Smoking is definitely the most important risk factor for lung cancer. Radon (222Rn) is a natural gas produced from radium (226Ra) in the decay series of uranium (238U). Radon exposure is the second most common cause of lung cancer and the first risk factor for lung cancer in never-smokers. Case–control studies have provided epidemiological evidence of the causative relationship between indoor radon exposure and lung cancer. Twenty-four case–control study papers were found by our search strategy from the PubMed database. Among them, seven studies showed that indoor radon has a statistically significant association with lung cancer. The studies performed in radon-prone areas showed a more positive association between radon and lung cancer. Reviewed papers had inconsistent results on the dose–response relationship between indoor radon and lung cancer risk. Further refined case–control studies will be required to evaluate the relationship between radon and lung cancer. Sufficient study sample size, proper interview methods, valid and precise indoor radon measurement, wide range of indoor radon, and appropriate control of confounders such as smoking status should be considered in further case–control studies.

Erratum to: An updated review of case–control studies of lung cancer and indoor radon-Is indoor radon the risk factor for lung cancer?

Acknowledgements section was missing. The publisher apologises for these errors.

The Prognostic Value of Residual Volume/Total Lung Capacity in Patients with Chronic Obstructive Pulmonary Disease

The prognostic role of resting pulmonary hyperinflation as measured by residual volume (RV)/total lung capacity (TLC) in chronic obstructive pulmonary disease (COPD) remains poorly understood. Therefore, this study aimed to identify the factors related to resting pulmonary hyperinflation in COPD and to determine whether resting pulmonary hyperinflation is a prognostic factor in COPD. In total, 353 patients with COPD in the Korean Obstructive Lung Disease cohort recruited from 16 hospitals were enrolled. Resting pulmonary hyperinflation was defined as RV/TLC > or = 40%. Multivariate logistic regression analysis demonstrated that older age (P = 0.001), lower forced expiratory volume in 1 second (FEV1) (P < 0.001), higher St. George Respiratory Questionnaire (SGRQ) score (P = 0.019), and higher emphysema index (P = 0.010) were associated independently with resting hyperinflation. Multivariate Cox regression model that included age, gender, dyspnea scale, SGRQ, RV/TLC, and 6-min walking distance revealed that an older age (HR = 1.07, P = 0.027), a higher RV/TLC (HR = 1.04, P = 0.025), and a shorter 6-min walking distance (HR = 0.99, P < 0.001) were independent predictors of all-cause mortality. Our data showed that older age, higher emphysema index, higher SGRQ score, and lower FEV1 were associated independently with resting pulmonary hyperinflation in COPD. RV/TLC is an independent risk factor for all-cause mortality in COPD.

Methodology of revision of Korean national cancer screening guideline

The National Cancer Screening Program (NCSP) was established to provide cancer screening services for low-income Medicaid recipients in 1999. Since then, the NCSP has expanded its target population to include National Health Insurance beneficiaries. Currently, the program targets the five most common types of cancer in Korea: stomach, liver, colorectal, breast, and cervical cancer. The National Cancer Center has been involved in developing and revising the practice guidelines for the NCSP in collaboration with the Ministry of Health and Welfare and related academic societies. The main methodological principles of development were determined as follows: an evidence-based approach to the development of recommendations on cancer screening was used, that the recommendation could be drawn by an adaptation process if evidence-based current reliable clinical practice guidelines were available, and that the level of evidence was assessed by methodologies. The process of recommendation development was divided into planning, development, and finalization steps. Planning tasks consisted of selection of clinical practice guideline topics, organization of a clinical practice guideline development group, reviewing the existing clinical practice guidelines, establishment of development plans, and definition of key questions. Development tasks consisted of steps including searching the literature evidence base, assessment of the quality of evidence, integration of evidence, and formulation of recommendations and deciding on the recommendation grade. The finalization tasks included external review, up-dating of the plan, and publication of the clinical practice guidelines.

The Korean guideline for lung cancer screening

Lung cancer is the leading cause of cancer death in many countries, including Korea. The majority of patients are inoperable at the time of diagnosis because symptoms are typically manifested at an advanced stage. A recent large clinical trial demonstrated significant reduction in lung cancer mortality by using low dose computed tomography (LDCT) screening. A Korean multisociety collaborative committee systematically reviewed the evidences regarding the benefits and harms of lung cancer screening, and developed an evidence-based clinical guideline. There is high-level evidence that annual screening with LDCT can reduce lung cancer mortality and all-cause mortality of high-risk individuals. The benefits of LDCT screening are modestly higher than the harms. Annual LDCT screening should be recommended to current smokers and ex-smokers (if less than 15 years have elapsed after smoking cessation) who are aged 55 to 74 years with 30 pack-years or more of smoking-history. LDCT can discover non-calcified lung nodules in 20 to 53% of the screened population, depending on the nodule positivity criteria. Individuals may undergo regular LDCT follow-up or invasive diagnostic procedures that lead to complications. Radiation-associated malignancies associated with repetitive LDCT, as well as overdiagnosis, should be considered the harms of screening. LDCT should be performed in qualified hospitals and interpreted by expert radiologists. Education and actions to stop smoking must be offered to current smokers. Chest radiograph, sputum cytology at regular intervals, and serum tumor markers should not be used as screening methods. These guidelines may be amended based on several large ongoing clinical trial results.

Assessment of the Quality of Clinical Practice Guidelines in Korea Using the AGREE Instrument

The objective of this study was to conduct the systematic evaluation of methodological quality of clinical practice guidelines (CPGs) in Korea. The authors conducted a very comprehensive literature search to identify potential CPGs for evaluation. CPGs were selected which were consistent with a predetermined criteria. Four reviewers evaluated the quality of the CPGs using the Appraisal of Guidelines, Research and Evaluation (AGREE) Instrument. AGREE item scores and standardized domain scores were calculated. The inter-rater reliability of each domain was evaluated using the intra-class correlation coefficient (ICC). Consequently, 66 CPGs were selected and their quality evaluated. ICCs for CPG appraisal using the AGREE Instrument ranged from 0.626 to 0.877. Except for the "Scope and Purpose" and "Clarity and Presentation domains", 80% of CPGs scored less than 40 in all other domains. This review shows that many Korean research groups and academic societies have made considerable efforts to develop CPGs, and the number of CPGs has increased over time. However, the quality of CPGs in Korea were not good according to the AGREE Instrument evaluation. Therefore, we should make more of an effort to ensure the high quality of CPGs.

Successful Sirolimus Treatment of Kaposi's Sarcoma in Multiple Pulmonary Nodules after Kidney Transplantation / 대한이식학회지

Kaposi's sarcoma is one of the most serious complications associated with immune suppression treatment after kidney transplantation. Because it usually manifestations as skin lesions or lymphadenopathies, its clinical suspicion and tissue diagnosis is relatively easy. However, Kaposi's sarcoma presented as multiple pulmonary nodules without skin manifestations is not easily detected early and usually has a deadly prognosis. We present the case of a 36-year-old male who underwent kidney transplantation 13 months ago and has been on tacrolimus and mycophenolate mofetil (MMF)-based immune suppression presented dry cough, blood tinged sputum, and multiple pulmonary nodules without any skin lesions. Both bronchoscopic washing cytology and fine needle aspiration cytology of peripheral lung tissues were performed but failed due to low cellular yields. A video-assisted thoracoscopic biopsy subsequently revealed Kaposi's sarcoma. Following the diagnosis, we changed the immune suppression from a tacrolimus and MMF-based regimen to a sirolimus-based regimen. Respiratory symptoms gradually disappeared and we found complete remission on follow-up radiologic evaluations. Thus sirolimus may be the preferred method of treatment for patients with immune suppression after kidney transplantation.

Urinary Transforming Growth Factor-beta1 is a Robust Predictor of Kidney Disease Progression / 대한신장학회잡지

BACKGROUND: TGF-beta1 is the main fibrogenic cytokine associated with human glomerulonephritis. TGF-beta1 levels were found to be significantly increased in the urine of patients with IgA nephropathy. However, urinary TGF-beta1 excretion has so far not been evaluated with respect to the risk of kidney disease progression. METHODS: In the current study, urine samples were taken for TGF-beta1 protein analysis from 37 patients diagnosed with IgA nephropathy on the day of renal biopsy, and patients were followed until either the date of serum creatinine doubling or until the end of the follow-up period. RESULTS: The median follow-up was 3.6 years (range, 0.4-6.2 years). Urinary TGF-beta1/creatinine ratios (TGF-beta1/Cr, pg/mg) were significantly higher in IgA nephropathy patients than in normal controls (10.7+/-1.92 versus 2.38+/-0.52). The area under the receiver-operating-characteristics curve was 0.78 (P<0.05, 95% confidence interval 0.61-0.90), indicating that urinary TGF-beta1/Cr is an excellent predictor of kidney disease progression. Univariate Cox regression analysis showed that urinary TGF-beta1/Cr was the most powerful predictor of serum creatinine doubling (p=0.0026, relative risk 1.09, 95% confidence interval 1.03-1.15). Furthermore, multivariate Cox regression analysis adjusted for other confounders revealed that urinary TGF-beta1/Cr was the only significant predictor of serum creatinine doubling. In contrast, serum TGF-beta1 levels were not found to be a risk factor of kidney disease progression. CONCLUSION: Our findings provide new evidence of a robust association between urinary TGF-beta1 and kidney disease progression in patients with IgA nephropathy.