Department of Obstetrics & Gynaecology, Women & Children Hospital, Chennai, India.
Indian J Med Res. 2011 Jul;134(1):40-6.
BACKGROUND & OBJECTIVES: Genital tuberculosis (GTB) is one of the major causes for severe tubal disease leading to infertility. Unlike pulmonary tuberculosis, the clinical diagnosis of GTB is difficult because in majority of cases the disease is either asymptomatic or has varied clinical presentation. Routine laboratory values are of little value in the diagnosis. An absolute diagnosis cannot be made from characteristic features in hysterosalpingogram (HSG) or laparoscopy. Due to the paucibacillary nature of GTB, diagnosis by mycobacterial culture and histopathological examination (HPE) have limitations and low detection rate. The objective of this study was to evaluate the efficacy of PCR technique, culture and histopathological examination in the diagnosis of GTB in female infertility.
This study included 72 infertile women who met the inclusion and exclusion criteria. After a detailed history and clinical examination all patients were subjected to investigations including pelvic sonogram, HSG and laparoscopy. Endometrial samples from were allocated for AFB smear, culture and HPE examination. Only 49 samples were available for PCR using IS 6110 and TRC 4 primers. In seven patients peritoneal fluid was also taken for culture and PCR. Based on the clinical profile and laparoscopic findings, a diagnostic criteria was derived to suspect GTB. Specific diagnostic tests were evaluated against this diagnostic criterion.
Laparoscopy was suggestive of tuberculosis in 59.7 per cent of cases, AFB smear was positive in 8.3 per cent, culture was positive in 5.6 per cent, HPE positive in 6.9 per cent and PCR was positive in 36.7 per cent of cases. Based on the diagnostic criteria, GTB was suspected in 28 of the 49 cases. On evaluating against the diagnostic criteria, the sensitivity of PCR, HPE and culture were 57.1, 10.7, 7.14 per cent respectively. The concordance of results between the clinical criteria and specific diagnostic tests were analysed by Kappa measure of agreement. The culture and HPE showed mild agreement with the clinical criteria, whereas PCR showed a moderate agreement. PCR was positive in Two of the 21 cases in whom GTB was not suspected. False positive PCR in these two cases were ruled out by multiple areas of sampling and re-sampling in one case. The PCR results were negative in 12 of the 28 cases. PCR using TRC 4 primers had a higher sensitivity (46.4%) than IS 6110 primers (25%) in detecting clinically suspected GTB.
INTERPRETATION & CONCLUSIONS: Our results showed that conventional methods of diagnosis namely, HPE, AFB smear and culture have low sensitivity. PCR was found to be useful in diagnosing early disease as well as confirming diagnosis in clinically suspected cases. False negative PCR was an important limitation in this study.
生殖器结核（GTB）是导致不孕的严重输卵管疾病的主要原因之一。与肺结核不同，GTB 的临床诊断较为困难，因为在大多数情况下，该病要么没有症状，要么表现出不同的临床症状。常规实验室值在诊断中几乎没有价值。在子宫输卵管造影（HSG）或腹腔镜检查中，无法根据特征性表现做出明确诊断。由于 GTB 的细菌数量较少，因此分枝杆菌培养和组织病理学检查（HPE）的诊断具有局限性和低检出率。本研究的目的是评估聚合酶链反应（PCR）技术、培养和组织病理学检查在女性不孕中诊断 GTB 的效果。
本研究纳入了 72 名符合纳入和排除标准的不孕女性。在详细的病史和临床检查后，所有患者均接受了包括盆腔超声、HSG 和腹腔镜检查在内的检查。子宫内膜样本用于进行 AFB 涂片、培养和 HPE 检查。仅对 49 份样本使用 IS 6110 和 TRC 4 引物进行了 PCR。在 7 名患者中，还抽取了腹腔液进行培养和 PCR。根据临床特征和腹腔镜检查结果，得出了一个诊断 GTB 的标准，并根据该标准评估了特定的诊断测试。
腹腔镜检查提示结核的占 59.7%，AFB 涂片阳性占 8.3%，培养阳性占 5.6%，HPE 阳性占 6.9%，PCR 阳性占 36.7%。根据诊断标准，49 例中有 28 例疑似 GTB。根据诊断标准评估结果，PCR、HPE 和培养的敏感性分别为 57.1%、10.7%和 7.14%。通过 Kappa 一致性测量分析了临床标准与特定诊断测试之间的结果一致性。培养和 HPE 与临床标准显示轻度一致，而 PCR 显示中度一致。PCR 在 21 例未怀疑 GTB 的病例中有 2 例呈阳性。在其中 1 例中，通过多处取样和重复取样排除了这两个病例的假阳性 PCR。在 28 例疑似 GTB 的病例中，PCR 结果为阴性的有 12 例。使用 TRC 4 引物的 PCR 检测 GTB 的敏感性（46.4%）高于使用 IS 6110 引物（25%）。
我们的结果表明，传统的诊断方法，即 HPE、AFB 涂片和培养，敏感性较低。PCR 被发现可用于诊断早期疾病，并可在疑似临床病例中确认诊断。假阴性 PCR 是本研究的一个重要局限性。
