背景:肺孢子菌肺炎(PCP)通常影响免疫功能低下的个体,而在有免疫能力的人中,它相对很少发生,在大多数情况下,肺孢子虫感染被检测为无症状定植。本研究旨在建立不同免疫状态(免疫功能低下和免疫功能低下)的人类宿主中肺孢子虫感染的患病率。使用分子诊断方法,并将其诊断价值与经典染色方法进行比较。
方法:我们使用了从保加利亚人群中肺孢子病患病率的前瞻性研究中收集到的数据。临床标本(包括咽喉分泌物,诱导痰,气管抽吸物,和支气管肺泡灌洗)从220名怀疑PCP的患者(153名免疫活性患者和67名免疫功能低下的患者)中收集,采用显微镜染色方法和实时PCR检测P。结果:38例(17%)标本(32例免疫功能低下患者和6例免疫功能正常受试者)中检测到病原体的DNA。从染色方法检查的所有220个临床样本中,Gomori染色仅检测到5个(2%)Jirovecii囊肿。所有PCP患者均接受甲氧苄啶-磺胺甲恶唑治疗,但是在其中十个(HIV阳性患者)中,这种疾病有致命的结果。
结论:这项研究是保加利亚的第一项研究,包括诊断人类肺孢子虫病的主要可用实验室方法。关于PCP的病因诊断,在我们的研究中,与染色方法相比,实时PCR的灵敏度更高。样品收集和检查方法的选择对实验室诊断的效率具有重要作用。
BACKGROUND: Pneumocystis pneumonia (PCP) commonly affects immunocompromised individuals, whereas in immunocompetent persons, it occurs relatively rarely, and in most cases, the Pneumocystis infection is detected as an asymptomatic colonization. The present
study aimed to establish the prevalence of Pneumocystis jirovecii infection in human hosts with different immune status (immunocompromised and immunocompetent), using molecular diagnostic methods, and to compare their diagnostic value with that of classical staining methods.
METHODS: We used the collected-to-this-moment data from a prospective
study on the prevalence of pneumocystosis among the Bulgarian population. Clinical specimens (including throat secretions, induced sputum, tracheal aspirates, and bronchoalveolar lavage) collected from 220 patients suspected of PCP (153 immunocompetent and 67 immunocompromised patients) were examined with microscopic staining methods and real-time PCR for detection of P. jirovecii. Results: DNA of the pathogen was detected in 38 (17%) specimens (32 immunocompromised patients and 6 immunocompetent subjects). From all 220 clinical samples examined by staining methods, only five (2%) P. jirovecii cysts were detected by the Gomori stain. All patients with PCP were treated with trimethoprim-sulfamethoxazole, but in ten of them (HIV-positive patients), the disease had a fatal outcome.
CONCLUSIONS: This
study is the first in Bulgaria including the main available laboratory methods for diagnosis of human pneumocystosis. Regarding the etiological diagnosis of PCP, in our
study the sensitivity of real-time PCR was higher compared to the staining methods. The choice of a method for sample collection and examination has an important role in the efficiency of the laboratory diagnostics.