Medizinische Universität Graz - Research portal
Selected Publication:
Niessner, S.
Pneumocystis jirovecii fungal load in the respiratory tract and comparison with serum beta-D-glucan level in immunocompromised patients
Humanmedizin; [ Diplomarbeit ] Medizinische Universität Graz; 2021. pp. 41
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- Authors Med Uni Graz:
- Advisor:
- Kessler Harald
- Stelzl Evelyn
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- Abstract:
- Abstract: Background: The diagnosis of Pneumocystis jirovecii pneumonia (PJP) has relied on microscopy with immunofluorescence. Nowadays, alternative diagnostic tests including detection and quantitation of P. jirovecii DNA based on real-time quantitative PCR and determination of serum beta-D-glucan (BDG) are increasingly used. Objectives: The aim of this pilot study was to evaluate the analytic performance of a new assay for detection and quantitation of P. jirovecii DNA. Furthermore, the fungal load of immunocompromised patients with suspected PJP was determined with two different methods and results were compared. Materials and Methods: Detection and quantitation of P. jirovecii DNA was done with the RIDA®GENE Pneumocystis jirovecii kit. DNA was extracted on the automated EMAG® nucleic acid extraction platform followed by amplification and detection on the LightCycler® 480 II instrument. For BDG testing, the Fungitell® Assay was run using a modified protocol employing the BCS XP System. The accuracy of the RIDA®GENE Pneumocystis jirovecii kit was determined utilizing an international reference panel. Furthermore, 8 anonymized left-over specimens that had been obtained from female and male patients with immunosuppression and suspected pneumocystis pneumonia were studied and results compared. Results: When the accuracy of the RIDA®GENE Pneumocystis jirovecii kit was evaluated, all vials containing (any dilution of) P. jirovecii were correctly identifed as positive and the vial without P. jirovecii was correctly identified as negative. When the clinical performance was evaluated, all samples tested positive with the molecular test system, while BDG testing resulted in 4 positives only. Conclusion: Detection and quantitation of P. jirovecii DNA based on real-time quantitative PCR appears to be the superior method when compared to serum BDG determination. Besides increased sensitivity, it is easier to handle and shows faster time-to-result allowing an earlier start of antifungal therapy. To underline these findings, further testing with a larger sample size is recommended.