• Tuberculosis and Respiratory Diseases
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• 제67권4호
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• pp.331-337
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• 2009

Background: The whole-blood interferon-gamma release assay (QuantiFERON-TB Gold [QFT-G]: Cellestis, Carnegie, Victoria, Australia) has been studied primarily for the use of diagnosing active pulmonary tuberculosis (TB) or latent TB. In the present study, the usefulness of QFT-G was evaluated for the diagnosis of extra-pulmonary tuberculosis (EP-TB). Methods: From June 2006 to February 2009, we evaluated the usefulness of QFT-G in patients (n=65) suspected with EP-TB, retrospectively. The diagnostic sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the QFT-G assay were analyzed. Results: EP-TB was diagnosed in 33 (51%) participants. The overall sensitivity, specificity, PPV, and NPV of the QFT-G assay for EP-TB were 78%, 79%, 81%, and 77%, respectively. Of the 33 with EP-TB, 14 (42%) were diagnosed with TB pleurisy, 7 (21%) with TB lymphadenitis, 7 (21%) with intestinal TB, and 5 (15%) with EP-TB in other sites. In subgroup analyses according by site of infection, the QFT-G showed 86% sensitivity, 64% specificity, and 78% NPV in TB pleurisy. On the other hand, the sensitivity, specificity, and NPV of the assay were 71%, 83% and 71%, respectively in TB lymphadenitis, and 86%, 100% and 88%, respectively in intestinal TB. Among the patients with suspected alternative site EP-TB, the sensitivity, specificity, and NPV of the assay were 50%, 80% and 67%, respectively. Conclusion: The QFT-G assay showed moderate diagnostic accuracy in EP-TB. However, negative QFT-G assay does not exclude EP-TB because of the low NPV of this assay.

• 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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• 제80권1호
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• pp.21-26
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• 2017

It is well established that health care workers (HCWs) have a considerably higher risk of occupationally acquired tuberculosis (TB). To reduce the transmission of TB to HCWs and patients, TB infection control programs should be implemented in health care settings. The first and most important level of all protection and control programs is administrative control. Its goals are to prevent HCWs, other staff, and patients from being exposed to TB, and to reduce the transmission of infection by ensuring rapid diagnosis and treatment of affected individuals. Administrative control measures recommended by the United States Centers for Disease Control and Prevention and the World Health Organization include prompt identification of people with TB symptoms, isolation of infectious patients, control of the spread of the pathogen, and minimization of time spent in health care facilities. Another key component of measures undertaken is the baseline and serial screening for latent TB infection in HCWs who are at risk of exposure to TB. Although the interferon-gamma release assay has some advantages over the tuberculin skin test, the former has serious limitations, mostly due to its high conversion rate.

• Tuberculosis and Respiratory Diseases
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• 제70권2호
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• pp.125-131
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• 2011

Background: The clinical manifestation of $M.$ $tuberculosis$ infection ranges from asymptomatic latent infection, to focal forms with minimal symptoms and low bacterial burdens, and finally to advanced tuberculosis (TB) with severe symptoms and high bacillary loads. We investigated the diagnostic sensitivity of the whole-blood interferon-${\gamma}$ release assay according to the wide spectrum of clinical phenotypes. Methods: In patients diagnosed with active TB that underwent $QuantiFERON^{(R)}$ (QFT) testing, the QFT results were compared with patients known to be infected with pulmonary tuberculosis (P-TB) and extra-pulmonary TB (EP-TB). In addition, the results of the QFT test were further analyzed according to the radiographic extent of disease in patients with P-TB and the location of disease in patients with EP-TB. Results: There were no statistical differences in the overall distribution of QFT results between 177 patients with P-TB and 84 patients with EP-TB; the positive results of QFT test in patients with P-TB and EP-TB were 70.1% and 64.3%, respectively. Among patients with P-TB, patients with mild extents of disease showed higher frequency of positive results of QFT test than that of patients with severe form (75.2% vs. 57.1%, respectively; p=0.043) mainly due to an increase of indeterminate results in severe P-TB. Patients with TB pleurisy showed lower sensitivity by the QFT test than those with tuberculous lymphadenitis (48.8% vs. 78.8%, respectively; p=0.019). Conclusion: Although QFT test showed similar results between overall patients with P-TB and EP-TB, individual sensitivity was different according to the radiographic extent of disease in P-TB and the location of disease in EP-TB.

• 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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• 제17권2호
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• pp.137-147
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• 2010

목적 : 본 연구는 소아에서 QuantiFERON-TB Gold(QTB) 검사의 임상적 유용성과 문제점을 평가하기 위해 시행되었다. 방 법: 2007년 1월부터 2009년 6월까지 본원에서 TST와 QTB를 시행 받은 소아청소년 112명의 의무 기록을 후향적으로 조사하였다. 결과 : TST와 QTB의 양성률은 각각 59.8%, 15.2%였고, 두 검사의 일치도는 낮았다($\kappa$=0.209). QTB의 민감도와 특이도는 각각 80.0%, 92.6%였다. QTB 양성율은 임상적 결핵군, 긴밀 접촉군, 일반 접촉군, 비접촉군에서 각각 80%, 14%, 0%, 2% 였으며, 판정보류의 빈도는 9.8%였다. QTB 추적 관찰이 시행된 환자 중, 초기 QTB 양성이었던 6명 중 5명은 치료 종료 후 평균 2.2개월까지 양성이 지속되었다. 결론 : 소아에서 QTB는 민감도가 낮고, 판정보류의 빈도가 높다는 단점이 있으나, 특이도가 높은 장점이 있으므로, TST의 특이도가 낮은 점을 보완하여 결핵의 진단 및 치료 결정에 활용될 수 있을 것으로 생각된다.

• 대한의생명과학회지
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• 제19권2호
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• pp.90-97
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• 2013

The tuberculin skin test (TST) and interferon gamma (IFN-${\gamma}$) release assay (IGRA) have been widely used for diagnosis of latent tuberculosis infection (LTBI). In order to overcome limitations of current LTBI diagnostic methods, the development of a novel molecular assay which is able to measure the IFN-${\gamma}$ messenger RNA (mRNA) expression level after stimulation with Mycobacterium tuberculosis (MTB) specific antigen was recently developed. The ability of a molecular assay to detect MTB infection was similar to commercial IGRA however, the optimal incubation time for stimulating IFN-${\gamma}$ was not yet established. Therefore, in this study the direct comparisons of MTB Ag stimulation times (4 and 24 hrs) were performed for diagnosis of MTB infection. Data showed that the coincident rate between QFT-GIT IFN-${\gamma}$ ELISA and IFN-${\gamma}$ RT-PCR (4 hrs) was 88.35% and that of QFT-GIT and IFN-${\gamma}$ RT-PCR (24 hrs) was 70.85%. Based on a receiver operating characteristic (ROC) curve, the 4 hrs-MTB specific Ag stimulation time for IFN-${\gamma}$ RT-PCR had the significant P value, 95% CI value, and AUC (P < 0.0001, 95% CI=0.82 to 1.02, and AUC=0.9214) in comparison with 24 hrs-MTB specific Ag stimulation time (P = 0.009, 95% CI=0.06 to 0.94, and AUC=0.7711). These results show that 4-hr was the most optimal MTB Ag stimulation time for performing IFN-${\gamma}$ RT-PCR. Although semi-quantitative RT-PCR had a few analytical limitations, it might be useful as an alternative molecular diagnostic method for detecting MTB infection.

• 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.

• 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.

• The Korean journal of internal medicine
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• 제33권6호
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• pp.1241-1251
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• 2018

Background/Aims: To estimate the level of agreement and positivity rates of latent tuberculosis infection (LTBI) tests prior to the use of tumor necrosis factor (TNF) inhibitors in relation to underlying rheumatic diseases and endemic tuberculosis levels. Methods: The Ovid-Medline, Embase, and Cochrane Libraries were searched for articles before October 2013 involving LTBI screening in rheumatic patients, including rheumatoid arthritis (RA), ankylosing spondylitis (AS), juvenile idiopathic arthritis (JIA), and psoriatic arthritis. Results: In pooled analyses, 5,224 rheumatic patients had undergone both a tuberculin skin test (TST) and an interferon-gamma release assay (IGRA) before TNF inhibitors use. The positivity of TST, QuantiFERON-TB Gold In Tube (QFT-GIT), and T-SPOT.TB (T-SPOT) tests were estimated to be 29%, 17%, and 18%, respectively. The agreement percentage between the TST and QFT-GIT, and between the TST and T-SPOT were 73% and 75%. Populations from low-to-moderate endemic TB presented with slightly less agreement (71% between TST and QFT-GIT, and 74% between TST and T-SPOT) than patients from high endemic countries (73% between TST and QFT-GIT, and 81% between TST and T-SPOT). By underlying disease stratification, a lower level of agreement between TST and QFT-GIT was found among AS (64%) than among JIA (77%) and RA patients (73%). Conclusions: We reaffirm the current evidence for accuracy of LTBI test done by TST and IGRA among rheumatic patients is inconsistent. Our stratified analysis suggests different screening strategies might be needed in clinical settings considering the endemic status in the patient's country of origin and the precise nature of underlying diseases.