老年长期护理机构中潜伏性结核病感染的诊断复杂性。

The complexity of diagnosing latent tuberculosis infection in older adults in long-term care facilities.

机构信息

Department of Medicine, Section of Infectious Diseases, Boston University School of Medicine, 801 Massachusetts Avenue, Rm 2012 Boston, MA 02118, USA; Department of Epidemiology, Boston University School of Public Health, Boston, Massachusetts, USA.

Department of Epidemiology, Boston University School of Public Health, Boston, Massachusetts, USA.

出版信息

Int J Infect Dis. 2016 Mar;44:37-43. doi: 10.1016/j.ijid.2016.01.007. Epub 2016 Jan 21.

DOI:10.1016/j.ijid.2016.01.007

PMID:26802447

Abstract

OBJECTIVES

In the USA, tuberculosis disease rates are highest in older adults. Diagnostic testing for latent tuberculosis infection (LTBI) has not been evaluated carefully in this group. The aim of this study was to define the relationship between tuberculin skin test (TST) results, T-SPOT.TB results, and T-cell responses to Mycobacterium tuberculosis antigens.

METHODS

Long-term care facility residents with known prior TST results (positive or negative) were retested with TSTs and T-SPOT.TB. Prior exposure to M. tuberculosis was assessed by quantifying T-cell activation to mycobacterial antigens in vitro.

RESULTS

The median age of the 37 participants was 77 years (range 57-98 years). Among 18 participants with a prior positive TST, three (16.7%) had a negative TST when retested (TST reversion); two had a negative T-SPOT.TB. Of the 15 who were historically and currently TST-positive, four (26.7%) had a negative T-SPOT.TB and one (6.7%) had a borderline result. Percentages of CD4+ T-cells responding to mycobacterial antigens were higher in participants with positive TST and T-SPOT.TB (18.2%) compared to those with a positive TST but negative T-SPOT.TB (6.4%, p=0.16) and negative TST and T-SPOT.TB (5.9%, p<0.001).

CONCLUSIONS

LTBI testing in older adults is complicated by TST reversion and TST-positive/T-SPOT.TB-negative discordance, which may reflect clearance of infection or waning immunity.

摘要

目的

在美国，结核病发病率在老年人中最高。针对潜伏性结核感染（LTBI）的诊断检测并未在该人群中进行仔细评估。本研究旨在定义结核菌素皮肤试验（TST）结果、T-SPOT.TB 结果以及 T 细胞对结核分枝杆菌抗原的反应之间的关系。

方法

对已知既往 TST 结果（阳性或阴性）的长期护理机构居民进行 TST 和 T-SPOT.TB 复测。通过体外定量检测 T 细胞对分枝杆菌抗原的激活来评估既往结核分枝杆菌暴露情况。

结果

37 名参与者的中位年龄为 77 岁（范围为 57-98 岁）。在 18 名既往 TST 阳性的参与者中，有 3 名（16.7%）复测时 TST 转为阴性（TST 逆转）；有 2 名 T-SPOT.TB 阴性。在 15 名既往和目前 TST 阳性的参与者中，有 4 名（26.7%）T-SPOT.TB 阴性，1 名（6.7%）结果为边界值。对分枝杆菌抗原产生反应的 CD4+T 细胞百分比在 TST 和 T-SPOT.TB 均为阳性的参与者中（18.2%）高于 TST 阳性但 T-SPOT.TB 阴性的参与者（6.4%，p=0.16）和 TST 和 T-SPOT.TB 均为阴性的参与者（5.9%，p<0.001）。