• Clinical and Experimental Pediatrics
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• 제59권6호
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• pp.256-261
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• 2016

Purpose: Latent tuberculosis infection (LTBI) in young children may progress to severe active tuberculosis (TB) disease and serve as a reservoir for future transmission of TB disease. There are limited data on interferon-${\gamma}$ release assay (IGRA) performance in young children, which our research aims to address by investigating the usefulness of IGRA for the diagnosis of LTBI. Methods: We performed a tuberculin skin test (TST) and IGRA on children who were younger than 18 years and were admitted to Chung-Ang University Hospital during May 2011-June 2015. Blood samples for IGRA were collected, processed, and interpreted according to manufacturer protocol. Results: Among 149 children, 31 (20.8%) and 10 (6.7%) were diagnosed with LTBI and active pulmonary TB, respectively. In subjects lacking contact history with active TB patients, TST and IGRA results were positive in 41.4% (29 of 70) and 12.9% (9 of 70) subjects, respectively. The agreement (kappa) of TST and IGRA was 0.123. The control group, consisting of non-TB-infected subjects, showed no correlation between age and changes in interferon-${\gamma}$ concentration after nil antigen, TB-specific antigen, or mitogen stimulation in IGRAs (P=0.384, P=0.176, and P=0.077, respectively). In serial IGRAs, interferon-${\gamma}$ response to TB antigen increased in IGRA-positive LTBI subjects, but did not change considerably in initially IGRA-negative LTBI or control subjects. Conclusion: The lack of decrease in interferon-${\gamma}$ response in young children indicates that IGRA could be considered for this age group. Serial IGRA tests might accurately diagnose LTBI in children lacking contact history with active TB patients.

• 대한의생명과학회지
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• 제24권2호
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• pp.138-142
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• 2018

The incidence of tuberculosis (TB) in the Republic of Korea remains high when compared to the incidence in other Organization for Economic Cooperation and Development (OECD) countries. The prompt diagnosis and effective treatment of latent TB infection (LTBI) are very important in terms of controlling the burden of TB. The tuberculin skin test (TST) has long been the "gold standard" assay for the diagnosis of LTBI. However, it can show false positive results due to Bacille Calmette-$Gu{\acute{e}}rin$ (BCG) vaccination and infection with many environmental nontuberculous mycobacteria (NTM). The interferon gamma release assay (IGRA) using Mycobacterium tuberculosis (MTB)-specific antigens, was developed for the detection of LTBI. The QuantiFERON-TB Gold In-Tube assay is one of the most commonly used forms of the IGRA. In order to compare the diagnostic efficacy of the TST and IGRA in relation to LTBI among BCG-vaccinated healthy donors, whole blood samples were collected from 51 participants, and the results of the TST and IGRA were compared. Of the 51 cases, 18 cases (35.3%) were positive and 33 cases (64.7%) were negative when using the TST, while four cases (7.8%) were positive and 47 cases (92.2%) negative when using the IGRA. There was no correlation between the size of the induration in the TST and the $IFN-{\gamma}$ protein level. In conclusion, the TST showed higher cross-reactivity among the BCG-vaccinated healthy participants, therefore, the IGRA might be the most suitable assay for the rapid screening of LTBI in BCG-vaccinated healthy population, or for TB contact investigation.

• 대한영상의학회지
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• 제82권6호
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• pp.1524-1533
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• 2021

목적 인터페론-감마 분비 검사(interferon-gamma release assay; 이하 IGRA) 결과가 양성인 의료종사자의 흉부 X선(chest X-ray; 이하 CXR) 및 CT 결과를 기반으로 결핵의 발생률을 조사하고, 결핵 진단에서 진단 영상의 추가적인 역할을 알아보고자 하였다. 대상과 방법 IGRA를 시행 받은 1976명의 의료 종사자 중에서 IGRA 양성자를 후향적으로 조사하였다. 상부 폐야의 군집 결절 또는 선형 음영을 흉부 X선 양성으로 간주하였고, CT 결핵소견은 활성, 활동성미정, 비활동성, 정상으로 분류하였다. 활성 또는 활동성미정을 CT 양성으로 정의하였다. 결과 IGRA 검사 결과 255명(12.9%)에서 양성이었다. CXR과 CT는 각각 249명(99.2%)과 113명(45.0%)에서 시행되었다. CXR 양성 소견은 249명 중 7명(2.8%), CT 양성 소견은 113명 중 9명(8.0%)에서 각각 나왔다. 9명의 CT 양성 대상자 중 활성 또는 활동성미정 결핵 소견은 각각 6명(5.3%)과 3명(2.7%)에서 발견되었다. Acid-fast bacilli 염색, 배양 및 결핵에 대한 polymerase chain reaction을 포함한 미생물적 검사는 9명의 CT 양성 피험자 모두에서 음성이었다. CT 양성 피험자 9명은 경험적 항결핵약물 치료를 받았고, 이 9명 중 3명은 CXR 음성 소견이었다. 결론 IGRA 양성 의료 종사자에서 CT 검사는 무증상 결핵을 진단하는 데 도움을 주었다.

• Journal of Preventive Medicine and Public Health
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• 제52권4호
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• pp.272-275
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• 2019

The 2018 National Guideline for Tuberculosis Control, which was published by the Korea Centers for Diseases Prevention and Control (KCDC), mandates conducting an epidemiological survey among close contacts of active tuberculosis patients at public institutions such as schools. In the procedure for these surveys, the tuberculin skin test (TST) is mandated as the screening test for latent tuberculosis infection in elementary school students. However, several guidelines recommend using the interferon-gamma releasing assay (IGRA) for contacts aged over 5 years with a Bacillus Calmette-$Gu{\acute{e}}rin$ vaccination history. The main reason for this is that IGRA has a higher specificity and lower false positive rate than TST. In addition, IGRA requires only a single visit to draw blood and the results are available within 24 hours. These advantages could promote cooperation from both parents and students in conducting these surveys. Thus, these findings regarding the benefits of IGRA for surveys of close contacts at elementary schools should be incorporated into the KCDC guideline.

• Tuberculosis and Respiratory Diseases
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• 제68권3호
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• pp.155-161
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• 2010

Background: The tuberculin skin test (TST) has limitations in diagnosing a latent tuberculosis infection (LTBI). The interferon-gamma release assay (IGRA) was introduced to middle- and high-school students since 2009 by the Korea Centers for Disease Control and Prevention. The aim was to evaluate the utility of IGRA in diagnosing LTBI in middle- and high-school students. Methods: From August 2007 to July 2009, among suspected LTBI students showing TST induration with a 10 mm diameter and over with a normal chest x-ray in school students of Jeju city, 341 students underwent a Quanti FERON-TB Gold In-Tube (QFT-IT) test to confirm LTBI. Results: From 348 students showing a positive TST, a QFT-IT test was carried out on 341 students. The positive QFT-IT rate was 52.8% (=180/341). The positive QFT-IT rate was higher in high-school boys with a 15~19 mm diameter of induration in TST. Conclusion: With the introduction of IGRA for diagnosing LTBI in middle- and high-school students, approximately 47% of students who show a TST induration with a 10 mm diameter and over can avoid taking unnecessary preventive chemotherapy. These results suggest that IGRA is useful for diagnosing and controlling LTBI in Korean students.

• 대한임상검사과학회지
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• 제48권3호
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• pp.225-229
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• 2016

결핵이란 결핵균에 의한 만성 감염질환으로 결핵균이 포함된 비말액을 통해 공기감염을 일으킨다. 대부분의 결핵감염자는 전염력이 없는 잠복감염상태만 유지하나 10%의 감염자 중 절반은 감염 후 1~2년 안에 발병하게 된다. 결핵감염자와 접촉이 있는 학생 74명을 대상으로 결핵 감염자 접촉관련 사전 조사 및 흉부 X-선 검사, TST 검사 및 IGRA 검사를 실시하였다. 1차 TST 검사에서 양성자는 9명, 음성은 65명으로 나타났으며, 음성 판독자는 2차 TST검사를, 양성 판독자는 IGRA 검사를 실시하였다. 1차 TST 양성자 9명 중 IGRA 검사에서 3명이 양성자로 나와 잠복 결핵감염 치료를 실시하였다. 1차 TST결과 음성자에 대한 재확인 TST 검사는 1차와 차이가 없었다. 결론적으로 잠복결핵감염율은 74명중 3명으로 4.05%로 나타났고, 잠복결핵감염자 색출을 위해서 다른 그룹에 대한 조사도 필요하다.

• 한국산업보건학회지
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• 제27권3호
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• pp.238-244
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• 2017

Objectives: The major objective of this study was to investigate the prevalence of and risk factors for latent tuberculosis infection (LTBI) among employees at a workers' compensation hospital. Methods: Among the 394 employees at Incheon Hospital, 362 were enrolled in the study. An interferon-gamma release assay(IGRA) for diagnosis of LTBI was performed using QuantiFERON$^{(R)}$ TB Gold In-Tube(QFT-IT). Risk factors for LTBI were analyzed using logistic regression analysis. Results: The overall prevalence of LTBI was 32.0%(116/362). The non-medical departments have a significantly high prevalence compared to medical departments(39.7% vs 23.2%). In multivariate logistic regression analysis, experience working in the pneumoconiosis hospital(OR, 3.6; 95% CI, 1.3-10.3) was associated with development of LTBI. Conclusions: Korean guidelines for the management of tuberculosis recommend annual regular health examinations for TB and LTBI for health care workers(HCWs). Considering the high prevalence of and risk factors for LTBI among non-HCWs, it suggests a need for annual regular health examinations for TB and LTBI for all employees at workers' compensation hospitals, including pneumoconiosis hospitals.

• Tuberculosis and Respiratory Diseases
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• 제83권4호
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• pp.283-288
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• 2020

Background: Latent tuberculosis (TB) infection among TB contacts is diagnosed using plain chest radiography and interferon-gamma release assays (IGRAs). However, plain chest radiographs often miss active TB, and the results of IGRA could fluctuate over time. The purpose of this study was to elucidate changes in the results of the serial IGRAs and in the findings of the serial submillisievert chest computed tomography (CT) scans among the close contacts of active pulmonary TB patients. Methods: Patients age 20 or older with active pulmonary TB and their close contacts were invited to participate in this study. Two types of IGRA (QuantiFERON-TB Gold In-Tube assay [QFT-GIT] and the T-SPOT.TB test [T-SPOT]) and submillisievert chest CT scanning were performed at baseline and at 3 and 12 months after enrollment. Results: In total, 19 close contacts participated in this study. One was diagnosed with active pulmonary TB and was excluded from further analysis. At baseline, four of 18 contacts (22.2%) showed positive results for QFT-GIT and T-SPOT; there were no discordant results. During the follow-up, transient and permanent positive or negative conversions and discordant results between the two types of IGRAs were observed in some patients. Among the 17 contacts who underwent submillisievert chest CT scanning, calcified nodules were identified in seven (41.2%), noncalcified nodules in 14 (82.4%), and bronchiectasis in four (23.5%). Some nodules disappeared over time. Conclusion: The results of the QFT-GIT and T-SPOT assays and the CT images may change during 1 year of observation of close contacts of the active TB patients.

• Pediatric Infection and Vaccine
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• 제23권1호
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• pp.18-24
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• 2016

목적: 국내와 같이 결핵의 유병률이 높은 지역에서 결핵을 정확하게 진단하는 것은 중요하다. 본 예비연구는 국내의 소아청소년에서 결핵진단 시 TST 및 2가지 IGRA 검사법 (QFT-G 및 T-SPOT.TB) 간의 일치도를 알아보고자 하였다. 방법: 2014년 1월부터 2015년 4월까지 잠복결핵감염 또는 결핵질환의 진단을 위해 서울아산병원을 방문한 20세 이하 환자 중, TST, T-SPOT.TB 및 QFT-G 검사 중 최소 2가지 이상의 검사를 동시에 시행한 경우를 연구에 포함하였다. 이들의 의무기록을 후향적으로 분석하여 각 검사 간의 일치도를 평가하였다. 결과: 연구에 포함된 총 20명의 연령의 중앙값은 13.3세(범위: 3.8-18.1세)이었고, 이 중 11명은 면역저하와 관련된 기저질환이 있었다. T-SPOT.TB와 QFT-G 결과의 일치도는 90%였으며, TST와 T-SPOT.TB의 일치도는 50%, TST와 QFT-G의 일치도는 42.9%였다. T-SPOT.TB, QFT-G 및 TST의 결핵질환에 대한 특이도는 93.3%, 86.7% 및 58.3%였다. 결론: T-SPOT.TB과 QFT-G 간의 일치도는 높으나 TST와 T-SPOT.TB 또는 QFT-G 간의 일치도는 낮았다. 추후 국내 소아청소년의 정확한 결핵의 진단을 위한 각 검사들의 일치도 및 진단적 유용성에 대한 추가적인 연구가 필요하다.

• Pediatric Infection and Vaccine
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• 제18권1호
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• pp.48-53
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• 2011

목 적 : 활동성 결핵의 진단으로 투베르쿨린 피부반응 검사(TST)가 널리 사용되어 왔으나 민감도가 낮고 BCG 예방접종을 한 경우 교차반응이 일어날 수 있는 한계가 있어 이를 극복하기 위해 인터페론감마검사(IGRA)에 대한 연구가 보고되고 있다. 이에 본 연구는 소아 활동성 결핵을 진단하는 초기검사로서 IGRA의 유용성에 대해 알아보았다. 방 법: 2007년 4월부터 2008년 8월까지 부산대학교병원 소아청소년과에서 활동성결핵이 의심되어 입원한 18세 이하의 환자 33명을 대상으로 성별, 나이, BCG 접종력, 임상양상과 IGRA 검사결과를 분석하였다. 결 과:총 33명의 환아 중 9명이 활동성 결핵으로 진단되었고 ELISpot에 양성은 10명, 음성은 23명이었다. 활동성 결핵이었던 환아는 모두 양성이었다. 검사의 민감도는 활동성 결핵 환자에서 100%이었다. 23명의 환아가 ELISpot에 음성 반응을 보였는데 이들은 모두 임상적으로 결핵이 아닌 것으로 확진되었고 검사의 특이도는 95.8%였다. 결 론:소아의 활동성 결핵 진단에 있어 ELISpot은 유용한 것으로 생각된다.