Kidane Dawit, Olobo Joseph O, Habte Abebe, Negesse Yohannes, Aseffa Abraham, Abate Getahun, Yassin Mohammed A, Bereda Kiflu, Harboe Morten
Armauer Hansen Research Institute (AHRI), Addis Ababa, Ethiopia.
J Clin Microbiol. 2002 Nov;40(11):4230-4. doi: 10.1128/JCM.40.11.4230-4234.2002.
Tuberculous lymphadenitis (TBLN) is a common form of extrapulmonary tuberculosis with multiple differential diagnoses. Demonstration of the etiologic agent by smear microscopy or culture of fine needle aspirate (FNA) specimens is often unsuccessful. FNA specimens from 40 patients presenting at a rural health center in South Ethiopia and diagnosed as positive for TBLN on the basis of clinical and cytological criteria were analyzed for mycobacterial DNA by PCR. Thirty (75%) had cervical lymphadenitis and 11 (27.5%) were seropositive for human immunodeficiency virus (HIV). Three primer sets were initially used to identify the causative agent at the genus (antigen 85 complex), complex (IS6110 insertion sequence), and species (pncA gene and allelic variation) levels. Among the forty TBLN cases, 35 (87.5%) were positive by PCR at the genus and complex levels. Based on PCR for detection of allelic variation at position 169, 24 (68.6%) of the 35 were positive for Mycobacterium tuberculosis and 6 (17.1%) were positive for M. bovis. These six were positive in additional PCR assays using the JB21-JB22 primer set, which is highly specific for M. bovis. Five (14.1%) showed amplification for both M. tuberculosis and M. bovis with the allele-specific primer set. Cooccurrence of pyrazinamide (PZA)-sensitive and -resistant M. tuberculosis in those five cases was indicated, since all were negative in assays with the JB21-JB22 primer set. This feature was seen in 3 of 11 HIV-positive and 2 of 29 HIV-negative individuals (P < 0.001).
among 35 PCR-positive cases of TBLN from southern Ethiopia, 29 (82.9%) were caused by M. tuberculosis and six (17.1%) were caused by M. bovis.
结核性淋巴结炎（TBLN）是肺外结核的一种常见形式，有多种鉴别诊断。通过涂片显微镜检查或细针穿刺抽吸（FNA）标本培养来证明病原体往往不成功。对在埃塞俄比亚南部一个农村卫生中心就诊的40例患者的FNA标本进行分析，这些患者根据临床和细胞学标准被诊断为TBLN阳性，采用聚合酶链反应（PCR）检测分枝杆菌DNA。30例（75%）有颈部淋巴结炎，11例（27.5%）人类免疫缺陷病毒（HIV）血清学阳性。最初使用三组引物在属（抗原85复合体）、复合体（IS6110插入序列）和种（pncA基因及其等位变异）水平鉴定病原体。在40例TBLN病例中，35例（87.5%）在属和复合体水平PCR呈阳性。基于检测第169位等位变异的PCR，35例中的24例（68.6%）结核分枝杆菌呈阳性，6例（17.1%）牛分枝杆菌呈阳性。这6例在使用对牛分枝杆菌高度特异的JB21-JB22引物组的额外PCR检测中呈阳性。5例（14.1%）在等位基因特异性引物组检测中结核分枝杆菌和牛分枝杆菌均呈扩增。这5例中显示同时存在吡嗪酰胺（PZA）敏感和耐药的结核分枝杆菌，因为在使用JB21-JB22引物组的检测中均为阴性。在11例HIV阳性个体中的3例和29例HIV阴性个体中的2例中观察到这一特征（P<0.001）。
在埃塞俄比亚南部35例PCR阳性的TBLN病例中，29例（82.9%）由结核分枝杆菌引起，6例（17.1%）由牛分枝杆菌引起。
