Performance of recombinase polymerase amplification assay for cutaneous leishmaniasis detection: a systematic review
Behailu Taye1, Myrthe Pareyn2, Eyob Getu3
1Department of Medical Laboratory Science, College of Medicine and Health Sciences, Dilla University, Dilla, Ethiopia. behailutaye096@gmail.com.
Background:
Sensitive and robust point-of-care (PoC) assays are urgently needed for the diagnosis of cutaneous leishmaniasis (CL). Recombinase polymerase amplification (RPA), an isothermal molecular assay, has shown promise for CL diagnosis using either a lateral-flow assay (LFA) or a mobile-suitcase-laboratory (MSL) platform. However, its diagnostic performance has been inconsistent across studies. This systematic review and meta-analysis aimed to determine the pooled sensitivity and specificity of RPA for CL diagnosis.
Methods:
A comprehensive search was conducted in Google Scholar, EMBASE, Web of Science, PubMed, and Scopus to identify studies that evaluated the diagnostic accuracy of RPA in suspected CL cases. The methodological quality of the included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. Using the GRADE approach, certainty of evidence was evaluated. A bivariate random-effects model was applied to perform the meta-analysis using R and Stata 14.2.
Results:
Nine articles comprising 14 datasets were included, with sample sizes ranging from 18 to 226 participants. Sensitivity in individual studies ranged from 55% to 100%, while specificity varied from 36% to 100%. The pooled sensitivity and specificity were 86% (95% CI: 72-93%, p < 0.001) and 93% (95% CI: 65-99%, p = 0.01), respectively, with an area under the curve (AUC) of 0.88 against microscopy and PCR. Subgroup analysis revealed that RPA-LFA had higher pooled sensitivity (93%, 95% CI: 78-98%) compared to MSL (69%, 95% CI: 51-83%). Blinding was unreported in 44% of the included studies, resulting in an unclear risk of bias that may skew the diagnostic accuracy results. The certainty of evidence for RPA sensitivity was rated as moderate.
Conclusions:
RPA demonstrated high specificity and good sensitivity for CL diagnosis but fell short of the 95% sensitivity threshold outlined in the WHO target product profile. In contrast to MSL, LFA appears to be a promising PoC method for diagnosing CL. Data on RPA-MSL remains limited, and its applicability to other Leishmania species causing CL is unclear. Future research should focus on the evaluation of RPA for Old World CL species and strains.
Prospero Registration:
CRD42023451076.
Clinical Trial Number:
Not applicable.
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