Diagnosis of toxoplasmosis in pregnancy. Evaluation of latex–protein complexes by immnunoagglutination

Abstract

The aim of this work was to obtain a reagent based on latex particles for ruling out acute toxoplasmosis in pregnant women by immunoagglutination (IA). Latex-protein complexes (LPC) were previously synthesized coupling the recombinant protein of Toxoplasma gondii P22Ag and the homogenate of the parasite to latex particles with different size, chemical functionality and charge density. LPC were tested in IA assays against a panel of 72 pregnant women serum samples. Results were analysed through receiver operating characteristic curves, determining area under the curve (AUC), sensitivity, specificity positive and negative predictive values (PPV and NPV, respectively). It was observed that the antigenicity of proteins was not affected during sensitization by either physical adsorption or covalent coupling. The best results in the sense of maximizing discrimination of low avidity sera from chronic ones were observed for the IA test based on latex particles with carboxyl functionality and the recombinant P22Ag, obtaining an AUC of 0·94, a sensitivity of 100% and a NPV of 100%. In this way, the proposed test could be useful for the toxoplasmosis diagnosis in pregnant women, with the advantages of being cheap, rapid and easy to be implemented.

Systematic Review and Meta-Analysis of Congenital Toxoplasmosis Diagnosis: Advances and Challenges

“…Fifteen articles presented diagnosis performance on molecular diagnosis and/or bioassay and 23 articles analyzed serological performance diagnosis. Twenty-two articles in this review aimed at diagnosis improvement, 9 of them using a combination of diagnosis assays to improve performance [ 7 , 14 , 15 , 21 , 30 , 62 – 64 , 69 ] and 12 employing some modification of available methodologies [ 6 , 27 , 32 , 34 , 39 , 42 – 44 , 46 , 47 , 56 , 60 ].…”

Toxoplasma gondii Infection and ABO Blood Group Association Among Pregnant Sudanese Women: A Case Study

“…The present results are in agreement with those conducted in Russia, and Prague showed that the seroprevalence was higher among subjects with blood group AB than among subjects with blood group O 25 , 27 previous studies reported in Baghdad province. 22 Previous studies suggested an association or relationship between the ABO blood group phenotypes and Toxoplasma , demonstrating that the parasite utilizes glycoconjugates that characterize the blood phenotypes of the ABO blood group system as potential receptors and the main route of infection. 18 , 19 Our present results disagree with the results that obtained by Faver et al, 12 in which there were no statistically significant differences between ABO blood group phenotypes and toxoplasmosis.…”

“…A homogenous appearance feature is interpreted as the absence of Toxoplasma gondii antibody (IgM/IgG), whereas clear serum agglutination is interpreted as the presence of Toxoplasma gondii antibody that may indicate or reflect either a past infection or evolving Toxoplasma gondii infection. [20][21][22]…”

“…However, three other similar studies did not find any evidence of a relationship between ABO blood typing and T. gondii. [18][19][20][21][22][23][24][25][26] Therefore, the present study aimed to assess the relationship between blood group phenotypes and toxoplasmosis as a risk factor among pregnant women in Rabak city and to correlate the prevalence of the disease with other risk factors in the study area.…”