Department of Rheumatology, Tel Aviv Medical Center, Tel Aviv, Israel.
Int J Tuberc Lung Dis. 2009 Nov;13(11):1427-32.
To compare the performance of QuantiFERON-TB Gold (QFT-G) with that of the tuberculin skin test (TST) in detecting latent tuberculosis (LTBI) among patients with rheumatoid arthritis (RA).
A total of 35 RA patients and 15 healthy controls underwent TST, QFT-G assays and chest X-ray and filled out a questionnaire on predisposing conditions for TB disease. Serum interferon gamma (IFN-gamma) levels were tested by an enzyme-linked immunosorbent assay.
Forty-five per cent of RA patients had a TST > 5 mm vs. 26% in healthy controls. In the RA patients, QFT-G was positive in 11.4%, negative in 60% and indeterminate in 28.6%. The overall agreement between TST and QFT-G was significantly lower in the RA population than in controls (56% vs. 84%). No correlation was found between the use of prednisone, methotrexate and QFT-G results or agreement between TST and QFT-G. A low IFN-gamma level (<4 pg/ml) was found in 51.5% of the RA patients. No correlation was found between serum IFN-gamma levels and QFT-G results.
The clinical significance of negative QFT-G in TST-positive patients with low TB risk remains to be assessed. The high rate of indeterminate results questions the clinical utility of QFT-G in the diagnosis of LTBI in RA patients.
比较结核菌素皮肤试验（TST）与 QuantiFERON-TB Gold（QFT-G）检测类风湿关节炎（RA）患者潜伏性结核（LTBI）的性能。
共 35 名 RA 患者和 15 名健康对照者接受了 TST、QFT-G 检测和胸部 X 线检查，并填写了一份关于结核病发病倾向的问卷。采用酶联免疫吸附试验检测血清干扰素γ（IFN-γ）水平。
45%的 RA 患者 TST>5mm，而健康对照组为 26%。在 RA 患者中，QFT-G 阳性率为 11.4%，阴性率为 60%，不确定率为 28.6%。RA 患者中 TST 和 QFT-G 的总体一致性明显低于对照组（56% vs. 84%）。泼尼松、甲氨蝶呤的使用与 QFT-G 结果或 TST 和 QFT-G 之间的一致性之间未发现相关性。51.5%的 RA 患者血清 IFN-γ水平较低（<4pg/ml）。未发现血清 IFN-γ水平与 QFT-G 结果之间存在相关性。
低结核风险 TST 阳性、QFT-G 阴性患者的临床意义仍有待评估。不确定结果的高发生率质疑 QFT-G 在 RA 患者 LTBI 诊断中的临床实用性。
