Division of Infection Control, Chiba University, Japan.
Division of Laboratory Medicine, Chiba University Hospital, Japan.
Intern Med. 2023 Nov 15;62(22):3321-3326. doi: 10.2169/internalmedicine.1006-22. Epub 2023 Mar 31.
Objective A T-SPOT.TB can yield indeterminate results under two test observation conditions: a high response to the nil in negative control wells (high nil-control) or a low response to the mitogen in positive control wells (low mitogen-control). The most strongly influential factors for these indeterminate results, however, have yet to be identified. Methods From June 1, 2015, to June 30, 2021, we conducted a 1:1 matched case-control, retrospective study. Patients Patients who underwent a T-SPOT.TB test at Chiba University Hospital. Results The study included 5,956 participants. Indeterminate results were found in 63 participants (1.1%), including high nil-control in 37 and low mitogen-control in 26. Human T-cell leukemia virus type 1 (HTLV-1) positivity was the only influencing factor associated with high nil-control (adjusted odds ratio=98.5, 95% confidence interval: 6.59-1,480). Conclusion Regarding the indeterminate results, all HTLV-1 positive participants had a high nil response and no low mitogen response. It was suspected that abnormally produced interferon γ caused a nonspecific reaction to the negative control well, resulting in a high nil response. Low mitogen-control, conversely, did not appear to have any statistically significant influential factors.
目的
T-SPOT.TB 在两种试验观察条件下可能出现不确定结果：阴性对照孔中对零值的高反应（高阴性对照）或阳性对照孔中对有丝分裂原的低反应（低有丝分裂原对照）。然而，这些不确定结果的最主要影响因素尚未确定。
方法
我们进行了一项 1:1 匹配的病例对照、回顾性研究。
对象
在千叶大学医院接受 T-SPOT.TB 检测的患者。
结果
该研究共纳入 5956 名参与者。63 名患者（1.1%）出现不确定结果，其中 37 名患者出现高阴性对照，26 名患者出现低有丝分裂原对照。人类 T 细胞白血病病毒 1 型（HTLV-1）阳性是与高阴性对照唯一相关的影响因素（调整后的优势比=98.5，95%置信区间：6.59-1480）。
结论
对于不确定结果，所有 HTLV-1 阳性患者均出现高阴性对照反应，无低有丝分裂原反应。怀疑异常产生的干扰素 γ 对阴性对照孔产生非特异性反应，导致高阴性对照反应。相反，低有丝分裂原对照似乎没有任何具有统计学意义的影响因素。
