Comparison Between Real-Time PCR, Conventional PCR and Different Staining Techniques for Diagnosing Pneumocystis Jiroveci Pneumonia From Bronchoalveolar Lavage Specimens

J Med Microbiol. 2004 Jul;53(Pt 7):603-607. doi: 10.1099/jmm.0.45528-0.


Between January 2002 and July 2003, 173 bronchoalveolar lavage (BAL) specimens from 150 patients (19 HIV-infected and 131 non-HIV-infected patients) were evaluated for identification of Pneumocystis jiroveci (formerly known as Pneumocystis carinii f. sp. hominis) using staining techniques, conventional PCR (mtLSUrRNA gene) and real-time PCR (MSG gene). Test results were compared to Pneumocystis pneumonia (PCP) confirmed by typical clinical findings and response to treatment. Sensitivity and specificity of the techniques were 60 and 100% for staining (where either one or both techniques were positive), 100 and 87.0% for conventional PCR and 100 and 84.9 % for real-time PCR, respectively. The use of a concentration of 10(3) copies of DNA per capillary of BAL as a cut-off (determined by real-time PCR) increased specificity from 84.9 to 98.6% without reducing the sensitivity of the technique. This technique is rapid (<3 h) and therefore of major interest in differentiating between asymptomatic carriage and PCP. A BAL specimen with <10(3) copies per capillary of Pneumocystis-specific DNA is more likely to indicate a chronic carrier state, but in such cases follow-up is required to ensure that the patient is not in the early stage of an active PCP.

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • AIDS-Related Opportunistic Infections / diagnosis
  • AIDS-Related Opportunistic Infections / microbiology
  • Bronchoalveolar Lavage Fluid / microbiology*
  • Carrier State / diagnosis
  • Carrier State / microbiology
  • DNA, Fungal / analysis
  • DNA, Fungal / isolation & purification
  • False Negative Reactions
  • False Positive Reactions
  • Humans
  • Immunocompromised Host
  • Pneumocystis carinii / cytology
  • Pneumocystis carinii / genetics
  • Pneumocystis carinii / isolation & purification*
  • Pneumonia, Pneumocystis / diagnosis*
  • Pneumonia, Pneumocystis / microbiology
  • Pneumonia, Pneumocystis / pathology
  • Polymerase Chain Reaction / methods*
  • Sensitivity and Specificity
  • Staining and Labeling / methods*


  • DNA, Fungal