A colorimetric in vitro drug sensitivity assay for Plasmodium falciparum based on a highly sensitive double-site lactate dehydrogenase antigen-capture enzyme-linked immunosorbent assay.

Abstract

Abstract. We report a double-site enzyme-linked lactate dehydrogenase immunodetection assay (DELI), a highly sensitive antigen-capture enzyme-linked immunosorbent assay, which proved to be more sensitive for the detection of Plasmodium falciparum than thick blood smears, as sensitive as the polymerase chain reaction, and probably more reliable. This technique can help to detect infra-microscopic parasitemias (one parasite in 10 6 -10 8 red blood cells) from biological samples, and being quantitative, provide a fast substitute to thick smears for epidemiologic purposes. The technique can also be used to measure the in vitro drug sensitivity of P. falciparum with greater ease, much greater speed, and simpler equipment than that required for the isotopic microtest. Results obtained with four antimalarial drugs upon 16 strains closely paralleled those obtained by the isotopic assay (R ϭ 0.95). In contrast with the latter, much lower parasite densities could be tested in the DELI assay (as low as 0.005%), thereby extending the number of isolates that can be investigated. The ease of implementation and low cost of the DELI-microtest may contribute to a revived interest in using in vitro methods to survey resistance to antimalarial drugs, so as to better predict future in vivo drug failures and provide public health recommendations.

Improvement of detection specificity of Plasmodium‐infected murine erythrocytes by flow cytometry using autofluorescence and YOYO‐1

“…Although not as specific as microscopy or as sensitive as other techniques (30,31), flow cytometry is a powerful analytical tool that offers all the advantages inherent to objective measurements on cellular events, automation, and analysis of huge numbers of samples. These characteristics make its utilization in malaria drug discovery an important advantage in terms of cost effectiveness and it has already been successfully used for testing human samples (32).…”

New approaches in antimalarial drug discovery and development: a review

“…Two enzyme-linked immunosorbent assays are available for drug testing; these assays use monoclonal antibodies that are specific for the parasite enzyme lactate dehydrogenase (Pf LDH) (Druilhe et al 2001) or a parasite histidine-rich protein (HRP)II (Noedl et al 2002). The assessment of parasite growth is effective in both of these tests.…”

Determination of immunoreactivity ofPlasmodium falciparum antigens, serum dilutions and biomaterials

“…Eadier studies also reported that high sensitivity and reactivity with 1:100 diluted serum for detection of antibody in malaria infected sera (21)(22)(23). Recent optimal sensitivity assay study of serum of Drulie et al, (24) found that 104 and 105 serum dilutions showed lowest positivity for detection of disease compared to 1:100 and 1:200 serum dilutions.…”