Kaustová J
National Reference Laboratory for M. kansasii, Regional Institute for Hygiene, Ostrava, The Czech Republic.
Eur J Med Res. 1996 May 24;1(8):393-403.
The routine diagnosis of tuberculosis and other mycobacterial diseases based on organism identification was completed during a period of one year in 730 patients, with serological IgG, IgM and IgA determination of antibodies against antigen 60 from M. bovis , strain BCG. The analysis was performed on 10 groups of patients consisting of 1) inflammatory diseases of the respiratory tract, 2) pericarditis, myocarditis, lymphadenitis and CNS diseases, 3) chronic non-inflammatory diseases of kidneys, liver and pancreas, 4) non-inflammatory diseases of the heart, sarcoidosis and pneumoconiosis, 5) tumor, 6) healthy people with TB contact, 7) inactive TB, 8) culture-positive pulmonary and extra-pulmonary TB, 9) culture-negative TB and extra-pulmonary TB, and 10) potentially pathogenic mycobacteria. The specificity of the test (100% negative cases in Group 6, composed of healthy people) is estimated at about 90%, in accordance with determinations made in other laboratories. In non-tuberculous patients, the specificity varied according to the analysed groups. Group 1 was largely unspecific for IgM (76% positives) but the specificity was acceptable for IgG (6.2% positives ) and IgA (7.4% positives). Group 2 was similar to Group 1. Group 3 was associated with positive IgA titers. Group 4 was only exceptiony seropositive and Group 5 was positive mainly for IgA (11. 4%) associated with lower respiratory tract ailments. This unspecific seropositivity was attributed to inapparent infections by PPM whose colonisation was favored by the particular disease of the patients. The sensitivity of serological measurements applied to the diagnosis of TB patients and PPM patients was similar, regardless if the disease was pulmonary or non-pulmonary, regardless if cultures were positive or not and, in our hands, was low (positivity for IgA about 30 %, for IgM about 10% and for IgG about 30%). This poor sensitivity observed with people presenting for treatment is attributed to an immune depression occuring mainly in elderly patients. The remarkable sensitivity of the serological instrument applied to culture-negative pulmonary and non-pulmonary TB cases as well as PPM cases makes the test a good adjuvant in cases of suspicion of TB. The assessment of the serological status of people under chemotherapy is worth the analysis, a high IgG level being associated with immunocompetence while the absence of IgG antibodies and/or the presence of IgA antibodies denotes an immunologically misdirected response potentially opening the way to chronic infections.
在730例患者中，基于病原体鉴定对结核病和其他分枝杆菌病进行常规诊断，为期一年，同时测定血清中针对牛分枝杆菌卡介苗株抗原60的IgG、IgM和IgA抗体。分析了10组患者，包括：1）呼吸道炎症性疾病；2）心包炎、心肌炎、淋巴结炎和中枢神经系统疾病；3）肾脏、肝脏和胰腺的慢性非炎症性疾病；4）心脏非炎症性疾病、结节病和尘肺病；5）肿瘤；6）有结核病接触史的健康人；7）非活动性结核病；8）培养阳性的肺结核和肺外结核；9）培养阴性的肺结核和肺外结核；10）潜在致病性分枝杆菌。根据其他实验室的测定结果，该检测的特异性（第6组由健康人组成，所有病例均为阴性）估计约为90%。在非结核患者中，特异性因分析的组别而异。第1组对IgM大多无特异性（阳性率76%），但IgG（阳性率6.2%）和IgA（阳性率7.4%）的特异性尚可接受。第2组与第1组相似。第3组与IgA滴度阳性有关。第4组仅有异常血清阳性，第5组主要是与下呼吸道疾病相关的IgA阳性（11.4%）。这种非特异性血清阳性归因于潜在致病性分枝杆菌的隐匿感染，患者的特定疾病有利于其定植。应用血清学检测诊断结核病患者和潜在致病性分枝杆菌患者的敏感性相似，无论疾病是肺部还是肺外的，无论培养结果是否为阳性，在我们的研究中，敏感性较低（IgA阳性率约30%，IgM约10%，IgG约30%）。在接受治疗的患者中观察到的这种低敏感性归因于主要发生在老年患者中的免疫抑制。应用血清学检测对培养阴性的肺结核和肺外结核病例以及潜在致病性分枝杆菌病例具有显著的敏感性，这使得该检测在怀疑结核病的病例中成为一种良好的辅助手段。对化疗患者血清学状态的评估值得分析，高IgG水平与免疫能力相关，而缺乏IgG抗体和/或存在IgA抗体则表示免疫反应方向错误，可能导致慢性感染。
