Comparative Evaluation Between the RealStar PCR Kit and the AmpliSens ()-FRT PCR Kit for Detecting in Non-HIV Immunocompromised Patients.

Background: Real-time PCR is more sensitive than microscopic examination for detecting . We compared the performance of two assays for detecting DNA: the RealStar PCR Kit 1.0 CE (Altona Diagnostics, Hamburg, Germany) and the AmpliSens ()-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 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). DNA load was significantly higher in the clinical PCP group than in the other groups (<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 burden in BAL fluids. Both assays may be useful as routine methods for detecting DNA in a clinical laboratory setting, though their results should be interpreted considering sample type.