Kappler M, Kraxner A, Reinhardt D, Ganster B, Griese M, Lang T
Children's University Hospital of the Ludwig-Maxmilians-University, Munich, Germany.
Thorax. 2006 Aug;61(8):684-8. doi: 10.1136/thx.2005.049536. Epub 2006 Jan 31.
Eradication of Pseudomonas aeruginosa in patients with cystic fibrosis (CF) is possible if initiated early in the course of colonisation. To detect P aeruginosa as early as possible is therefore a major goal. This study was undertaken to validate a commercialised test for the detection of serum Pseudomonas antibodies in patients with CF.
A representative cross sectional analysis of serum antibodies against three Pseudomonas antigens (alkaline protease, elastase, and exotoxin A) was performed in 183 patients with CF of mean age 16.7 years and FEV1 85.9% predicted. The results were correlated with microbiological results from the previous 2 years to calculate sensitivity, specificity, positive and negative predictive values. The following 2 years were assessed to determine prognostic predictive values.
A combination of all three tested antibodies yielded the best results with a sensitivity of 86%, specificity of 96%, and a positive predictive value of 97%. These values were higher if only patients in whom sputum cultures were available were considered (n = 76, sensitivity 95%, specificity 100%, positive predictive value 100%). The prognostic positive predictive value was high in intermittently infected patients (83%) but low in patients free of infection (33%), whereas the prognostic negative predictive value was high in patients free of infection (78%) and low in intermittently infected patients (58%).
Regular determination of serum antibodies may be useful in CF patients with negative or intermittent but not with positive P aeruginosa status. A rise in antibody titres indicates probable infection and eradication treatment may be initiated even in the absence of microbiological detection of P aeruginosa.
如果在囊性纤维化（CF）患者定植过程的早期开始治疗，根除铜绿假单胞菌是有可能的。因此，尽早检测铜绿假单胞菌是一个主要目标。本研究旨在验证一项用于检测CF患者血清中铜绿假单胞菌抗体的商业化检测方法。
对183例平均年龄16.7岁、第一秒用力呼气容积（FEV1）为预测值85.9%的CF患者进行了针对三种铜绿假单胞菌抗原（碱性蛋白酶、弹性蛋白酶和外毒素A）的血清抗体代表性横断面分析。将结果与前两年的微生物学结果相关联，以计算敏感性、特异性、阳性和阴性预测值。对接下来的两年进行评估以确定预后预测值。
所有三种检测抗体的组合产生了最佳结果，敏感性为86%，特异性为96%，阳性预测值为97%。如果仅考虑有痰培养结果的患者（n = 76，敏感性95%，特异性100%，阳性预测值100%），这些值会更高。间歇性感染患者的预后阳性预测值较高（83%），但未感染患者较低（33%），而未感染患者的预后阴性预测值较高（78%），间歇性感染患者较低（58%）。
定期测定血清抗体可能对铜绿假单胞菌状态为阴性或间歇性感染而非阳性的CF患者有用。抗体滴度升高表明可能感染，即使在未检测到铜绿假单胞菌微生物学证据的情况下也可开始根除治疗。
