Assessment of Plasmodium antigens and CRP in dried blood spots with multiplex malaria array

The objective of this study was to evaluate the applicability of DBS with a commercial multiplex malaria assay, developed to concurrently measurePlasmodium antigens, histidine-rich protein 2 (HRP2),Plasmodium lactate dehydrogenase (pLDH), and a host inflammatory biomarker, C-reactive protein (CRP), in whole blood. The assay conditions were optimized for DBS, and thermal stability for measurement ofPlasmodium antigens and CRP in dried blood were determined. Performance of the multiplex assay on matched DBS and whole blood pellet samples was also evaluated using the clinical samples. The results indicate the acceptable performance in multiplex antigen detection using DBS samples. At cutoff levels for DBS, with a diagnostic specificity with a lower 95% confidence bound  >  92%, diagnostic sensitivities against polymerase chain reaction (PCR)–confirmed malaria for HRP2,Pf LDH,Pv LDH, and Pan LDH were 93.5%, 80.4%, 21.3%, and 55.6%, respectively. The half-life of pLDH was significantly less than that of HRP2 in thermal stability studies. Results with DBS samples collected from Peru indicate that the uncontrolled storage conditions of DBS can result in inaccurate reporting for infection withP. falciparum parasites withhrp2/3 deletions. With careful consideration that minimizing the unfavorable DBS storage environment is essential for ensuring integrity of heat-labilePlasmodium antigens, DBS samples can be used as an alternative to liquid whole blood to detectP. falciparum ...
Source: Journal of Parasitic Diseases - Category: Parasitology Source Type: research