Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases
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Clin. Microbiol. Infect. · Oct 2011
Comparative StudyReal-time PCR assay-based strategy for differentiation between active Pneumocystis jirovecii pneumonia and colonization in immunocompromised patients.
Diagnosis of pneumocystosis usually relies on microscopic demonstration of Pneumocystis jirovecii in respiratory samples. Conventional PCR can detect low levels of P. jirovecii DNA but cannot differentiate active pneumonia from colonization. In this study, we used a new real-time quantitative PCR (qPCR) assay to identify and discriminate these entities. ⋯ Two cut-off values of 120 and 1900 TFEq/mL were proposed to discriminate active pneumonia from colonization, with a grey zone between them. In conclusion, this qPCR assay discriminates active pneumonia from colonization. This is particularly relevant for patient management, especially in non-human immunodeficiency virus (HIV)-infected immunocompromised patients, who often present low-burden P. jirovecii infections that are not diagnosed microscopically.