Comparison of PneumID real-time PCR assay with Amplex eazyplex LAMP assay for laboratory diagnosis of Pneumocystis jirovecii Pneumonia

Willy W Y Ng; Yolanda I I Ho; Ann H Wong; Eddie C M Leung; Alfred L H Lee; Viola C Y Chow

doi:10.1093/mmy/myac043

Comparison of PneumID real-time PCR assay with Amplex eazyplex LAMP assay for laboratory diagnosis of Pneumocystis jirovecii Pneumonia

Med Mycol. 2022 Jun 14:myac043. doi: 10.1093/mmy/myac043. Online ahead of print.

Authors

Willy W Y Ng¹, Yolanda I I Ho², Ann H Wong², Eddie C M Leung², Alfred L H Lee², Viola C Y Chow²

Affiliations

¹ Department of Microbiology, Alice Ho Miu Ling Nethersole Hospital, Hong Kong, China.
² Department of Microbiology, Prince of Wales Hospital, Hong Kong, China.

PMID: 35700147
DOI: 10.1093/mmy/myac043

Abstract

We compared PneumID PCR with Amplex eazyplex LAMP assay for the diagnosis of Pneumocystis jirovecii pneumonia (PJP). Both assays enable accurate diagnosis of definite PJP. Cut-off cycle threshold of the PneumID assay was < 26.68 while the cut-off time-to-positivity of the eazyplex assay was 16:02 (minutes:seconds). The positive and negative percentage agreement of eazyplex assay with PneumID assay was 75.0% and 100.0% respectively, while the overall agreement was substantial with kappa = 0.80. For both assays, establishment of cut-off values to differentiate probable PJP from colonization was not feasible as results overlapped.

Keywords: Pneumocystis jirovecii pneumonia; LAMP assay; PCR assay; diagnosis.

Plain language summary

Both PneumID PCR and Amplex eazyplex LAMP assay enable accurate diagnosis of definite Pneumocystis jirovecii pneumonia (PJP). PneumID assay was more sensitive than eazyplex assay for detection of P. jirovecii. However, differentiation between probable PJP from colonization was not feasible.