Comparative Evaluation Between the RealStarPneumocystis jiroveciiPCR Kit and the AmpliSensPneumocystis jirovecii(carinii)-FRT PCR Kit for DetectingP. jiroveciiin Non-HIV Immunocompromised Patients

Abstract

Background Real-time PCR is more sensitive than microscopic examination for detecting Pneumocystis jirovecii . We compared the performance of two assays for detecting P. jirovecii DNA: the RealStar Pneumocystis jirovecii PCR Kit 1.0 CE (Altona Diagnostics, Hamburg, Germany) and the AmpliSens Pneumocystis jirovecii ( carinii )-FRT PCR kit (InterLabService Ltd., Moscow, Russia). Methods We used 159 samples from the lower respiratory tract (112 bronchoalveolar lavage [BAL] fluid, 37 sputum, and 10 endotracheal aspirate [ETA] samples) of non-HIV immunocompromised patients. Nested PCR and sequencing were used to resolve discordant results. The performance of the two assays was evaluated according to clinical categories (clinical Pneumocystis pneumonia [PCP], possible PCP, or unlikely PCP) based on clinical and radiological observations. Results The positive and negative percent agreement values were 100% (95% confidence interval [CI], 85.4–100%) and 96.6% (95% CI, 90.9–98.9%), respectively, and kappa was 0.92 (95% CI, 0.84–0.99). P. jirovecii DNA load was significantly higher in the clinical PCP group than in the other groups ( P <0.05). When stratified by sample type, the positive rate for BAL fluids from the clinical PCP group was 100% using either assay, whereas the positive rate for sputum/ETA samples was only 20%. Conclusions The two assays showed similar diagnostic performance and detected low P. jirovecii burden in BAL fluids. Both assays may be useful as routine methods for detecting P. jirovecii DNA in a clinical laboratory setting, though their results should be interpreted considering sample type.

A New Age in Molecular Diagnostics for Invasive Fungal Disease: Are We Ready?

“…The percentage of positive results was more variable for the "possible PCP" category, ranging from 54.5% (Bio-Evolution) to 86.4% (AmpliSens PCR), but all four assays were effective for PCP diagnosis. More recently, the performance of the RealStar P. jirovecii PCR Kit 1.0 EC (Altona Diagnostics, Hamburg, Germany) was compared with the AmpliSens PCR assay (Huh et al, 2019). The positive and negative percent agreements were 100 and 96.6%, respectively, and kappa was 0.92.…”

Performance of the RealStar®Pneumocystis jirovecii PCR kit for the diagnosis of Pneumocystis pneumonia

“…in the literature. [8][9][10][11][12][13][14] Most of these kits target the mtLSU gene and show good performance for PCP diagnosis. A Working group of the International Society for Human and Animal Mycology recently evaluated 19 PCR assays, including 9 commercial kits, 6 and found that most commercial kits display a specificity of 100% and a sensitivity between 88.8 and 100% for P jirovecii DNA detection.…”

“…Surprisingly, in the only other study that evaluated the RealStar ® Pneumocystis jirovecii PCR Kit for PCP diagnosis, the positivity rate was 100% for BAL specimens, but only 20% for sputum/endotracheal aspirates. 13 This is probably due by the procedure for obtaining these respiratory specimens.…”

A New PCR-Based Assay for Testing Bronchoalveolar Lavage Fluid Samples from Patients with Suspected Pneumocystis jirovecii Pneumonia

“…With regard to PJ qPCR assays, the choice of target genes for amplification remains an open issue [7]. Recently, Huh et al [19] showed the similarity of two commercial assaysone of which was capable of amplifying the mitochondrial large subunit (mtLSU) of a ribosomal RNA gene-in detecting low PJ loads in BAL fluids. Very recently, Dellière et al [20] found that an automated commercial reverse-transcriptase qPCR (~2.2 h workflow) was more sensitive than their in-house qPCR assays (~5 h workflow), which amplified both mtSSU and mtLSU for detecting PJ in respiratory samples.…”