Foster Rukhsana, Ferguson Thomas W, Rigatto Claudio, Lerner Blake, Tangri Navdeep, Komenda Paul
Seven Oaks General Hospital Renal Program, 2PD12 - 2300 McPhillips Street, Winnipeg, MB R2V 3M3 Canada ; Department of Medicine, University of Manitoba, Winnipeg, Canada.
Seven Oaks General Hospital Renal Program, 2PD12 - 2300 McPhillips Street, Winnipeg, MB R2V 3M3 Canada ; Chronic Disease Innovation Centre, Seven Oaks General Hospital, Winnipeg, Canada ; Department of Medicine, University of Manitoba, Winnipeg, Canada.
Can J Kidney Health Dis. 2016 Jun 7;3:28. doi: 10.1186/s40697-016-0119-4. eCollection 2016.
Reactivation of latent Mycobacterium tuberculosis infection (LTBI) is a health concern for patients on dialysis or receiving a kidney transplant, as these patients are often immunosuppressed. The most frequently used test for LTBI screening in this population is the tuberculin skin test (TST). The diagnostic accuracy (sensitivity and specificity) of the TST in a contemporary North American or Western European dialysis population is unknown.
Our objective was to determine the diagnostic accuracy and clinical utility of the two-step TST in patients receiving dialysis.
This is a retrospective cohort study.
This study is set at four tertiary dialysis units across Winnipeg, Manitoba.
There are 483 chronic hemodialysis and peritoneal dialysis patients in the study.
The measurements are sensitivity and specificity of the TST with respect to abnormal chest X-ray.
All patients received a two-step TST and assessment of risk factors for prior tuberculosis (TB) infection between February 2008 and December 2008. This cohort was retrospectively linked to our tuberculosis registry to ascertain if prophylaxis was received for LTBI.
At an induration cutoff of 5 mm, 62 (13 %) patients had a positive two-step TST. Patients with a known Bacillus Calmette-Guérin (BCG) vaccination were more likely to test positive (50 % of those with a positive TST had a BCG versus 34 % with a negative TST, p = 0.05). Using a diagnostic gold standard of an abnormal chest X-ray as a proxy for LTBI, the sensitivity of the TST was only 14 % and the specificity was 88 %. Only 8 of 62 patients with a positive TST (13 %) received prophylaxis for LTBI. None of the patients who tested negative were treated.
There is a lack of a truly accurate gold standard for LTBI.
The TST has limited diagnostic and clinical utility for LTBI screening in patients on dialysis. Further research into the diagnostic accuracy of interferon-gamma release assays and a revision of LTBI screening guidelines in patients on dialysis should be considered.
潜伏性结核分枝杆菌感染（LTBI）的重新激活是透析患者或接受肾移植患者的健康问题，因为这些患者通常免疫功能低下。该人群中最常用的LTBI筛查试验是结核菌素皮肤试验（TST）。当代北美或西欧透析人群中TST的诊断准确性（敏感性和特异性）尚不清楚。
我们的目的是确定两步法TST在透析患者中的诊断准确性和临床实用性。
这是一项回顾性队列研究。
本研究在加拿大曼尼托巴省温尼伯市的四个三级透析单位进行。
本研究中有483例慢性血液透析和腹膜透析患者。
测量TST相对于胸部X线异常的敏感性和特异性。
2008年2月至2008年12月期间，所有患者均接受了两步法TST以及既往结核（TB）感染危险因素的评估。该队列通过回顾性方式与我们的结核病登记处关联，以确定是否接受了LTBI预防治疗。
硬结直径临界值为5毫米时，62例（13%）患者两步法TST呈阳性。已知接种过卡介苗（BCG）的患者检测呈阳性的可能性更大（TST阳性者中有50%接种过BCG，而TST阴性者中这一比例为34%，p = 0.05）。以胸部X线异常作为LTBI的诊断金标准，TST的敏感性仅为14%，特异性为88%。62例TST阳性患者中只有8例（13%）接受了LTBI预防治疗。TST阴性的患者均未接受治疗。
缺乏真正准确的LTBI金标准。
TST在透析患者LTBI筛查中的诊断和临床实用性有限。应考虑进一步研究干扰素-γ释放试验的诊断准确性，并修订透析患者的LTBI筛查指南。
