SPA-ELISA检测卡氏肺孢子虫抗原的研究

目的 探讨SPAK-ELISA检测卡氏肺孢子虫抗原对诊断卡氏肺孢子虫肺炎的价值。 方法 采用SPA-ELISA检测免疫抑制大鼠模型在不同时期肺泡灌洗液(BALF)和血清中肺孢子虫(PC)抗原,以及造血干细胞移植并发肺炎患者痰液和血清抗原,并与病原学检查结果比较。 结果 感染大鼠于用药后第4周,BALF中PC抗原,以及肺组织印片和BALF涂片包囊检查开始出现阳性,但前者阳性率(60％)高于后者(20％和40％),而且全部阳性达到的时间(8周)也早于后者(10周)。第10周有2只鼠血清抗原阳性,但此后又转阴。30例肺炎患者痰液抗原阳性8例,阳性率为26.67％,8例抗原阳性患者中只有3例发现包囊,符合率为37.5％。血清抗原检测全部阴性。 结论 SPA-ELISA检测痰液和肺泡灌洗液抗原比病原学检查敏感性高,而检测血清抗原不适用于诊断卡氏肺孢子虫肺炎。

STUDY ON DETECTION OF PNEUMOCYSTIS CARINII ANTIGEN USING SPA-ELISA

Objective To assess the value of detecting Pneumocystis carinii (PC) antigens with SPA-ELISA for diagnosis of P. carinii pneumonia. Methods PC antigens were detected by SPA-ELISA in bronchoalveolar lavage fluid(BALF). sera of immuno-suppressed rats and the sputum and serum of patients with pneumonia after hematopoietic stem cell transplant(HSCT). The results were compared with that of pathogenic examination. Results At the 4th week after treatment, PC antigens in the BALF, PC cysts in lung impression smears and in BALF smears of rats were detected. The rate of detectable antigens in the BALF (60%) was higher than that of the cysts in lung impression smears (20%) and in BALF smears (40%). The time at which PC antigens in the BALF of all animals were positive (at the 8th week) was earlier than that which was found in the smears (at the 10th week). Serum antigens were positive in 2 specimens at the 10th week, after which they became negative. In 30 patients with pneumonia after HSCT, 8 were positive in sputum antigens for a rate of 26. 67% (8/30). Only 3 of the 8 antigen-positive patients had detectable cysts (37. 5%). The serum antigens of patients were negative Conclusion The sensitivity of detecting PC antigens in sputum and BALF by SPA-ELISA is greater than that by pathogenic examination. It was not suitable to detect PC antigens in serum for diagnosis of P. carinii pneumonia.