Malaria serology: performance of six Plasmodium falciparum antigen extracts and of three ways of determining serum titers in IgG and IgM-ELISA

Authors

  • Maria Carmen Arroyo Sanchez Instituto de Medicina Tropical de São Paulo; Laboratório de Sotoepidemiologia
  • Sandra do Lago Moraes de Avila Instituto de Medicina Tropical de São Paulo; Laboratório de Sotoepidemiologia
  • Vera de Paula Quartier-Oliveira Instituto de Medicina Tropical de São Paulo; Laboratório de Sotoepidemiologia
  • Antonio Walter Ferreira Instituto de Medicina Tropical de São Paulo; Laboratório de Sotoepidemiologia

Keywords:

Malaria, Serology, ELISA, Plasmodium falciparum, Antigen extracts

Abstract

The study evaluated six Plasmodium falciparum antigen extracts to be used in the IgG and IgM enzyme-linked immunosorbent assays (ELISA), for malaria diagnosis and epidemiological studies. Results obtained with eighteen positive and nine negative control sera indicated that there were statistically significant differences among these antigen extracts (Multifactor ANOVA, p< 0.0001). Urea, sodium deoxycholate and Zwittergent antigen extracts performed better than did the three others, their features being very similar for the detection of IgG antibodies. Urea, alkaline and sodium deoxycholate antigen extracts proved to be better than the others for the detection of IgM antibodies. A straight line relationship was found between the optical densities (or their respective log 10) and the log 10 of antibody dilutions, with a very constant slope. Thus serum titers could be determined by direct titration and by two different equations, needing only one serum dilution. For IgM antibody detections, log 10 expression gave results that better correlated with direct titration (95% Bonferroni). For IgG antibody detections, the titer differences were not significant. The reproducibility of antibody titers and antigen batches was also evaluated, giving satisfactory results.

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Published

1993-12-01

Issue

Section

Parasitology

How to Cite

Sanchez, M. C. A., Avila, S. do L. M. de, Quartier-Oliveira, V. de P., & Ferreira, A. W. (1993). Malaria serology: performance of six Plasmodium falciparum antigen extracts and of three ways of determining serum titers in IgG and IgM-ELISA . Revista Do Instituto De Medicina Tropical De São Paulo, 35(6), 495-502. https://revistas.usp.br/rimtsp/article/view/29095