Frequency of HLA-DQA1 and DQB1 alleles in fetuses with toxoplasmosis: association with the parasite genotype and the parasite load

• Grant number: 10/15022-1
• Support type: Regular Research Grants
• Duration: March 01, 2011 - August 31, 2013
• Field of knowledge: Health Sciences - Medicine - Maternal and Child Health
• Principal researcher: Thelma Suely Okay
• Grantee: Thelma Suely Okay
• Home Institution: Instituto de Medicina Tropical de São Paulo (IMT). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Assoc. researchers: Paulo Tadashi Shimokawa

Abstract

Very little is known on the genetic predisposition to toxoplasmosis and the influence of the patient's genome and the parasite genotype in the outcome of infection, however, it is possible that certain HLA alleles could be associated with more severe infections, or on the contrary, could act as protective factors. Three parasite genotypes have already been described and associated with higher virulence (type I, predominating in ocular toxoplasmosis and encephalitis in HIV patients), lower virulence (type II predominating in congenital infections), and intermediate virulence (type III, predominating in other animals). One hundred amniotic fluid samples or fetal blood of patients with toxoplasmosis (convenience casuistic), and other 100 samples from a control group (pregnant women over 35 years of age submitted to amniocentesis to perform the fetal karyotype, and fetuses born at term from whom placenta cord blood will be collected). Samples of both groups will be analyzed with respect to the presence of HLA (DQA1 and DQB1) alleles by multiplex-PCR, and samples of the study group (with toxoplasmosis) will have the parasite genotyped by multiplex-nested-PCR followed by RFLP and DNA sequencing, and the parasite load evaluated by Real Time PCR. This new approach in the congenital toxoplasmosis model, i.e., determining the genetic profile of the patient and the parasite, as well as the parasite load might be useful to indicate the best therapeutic choice to the host-parasite unit, possibly leading to a future impact on the morbidity and mortality attributable to toxoplasmosis. (AU)

Scientific publications

(5)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

YAMAMOTO, LIDIA; TARGA, LILIA S.; SUMITA, LAURA M.; SHIMOKAWA, PAULO T.; RODRIGUES, JONATAS C.; KANUNFRE, KELLY A.; OKAY, THELMA S. Association of Parasite Load Levels in Amniotic Fluid With Clinical Outcome in Congenital Toxoplasmosis. OBSTETRICS AND GYNECOLOGY, v. 130, n. 2, p. 335-345, AUG 2017. Web of Science Citations: 0.

WILSON DOMINGUES; KELLY APARECIDA KANUNFRE; JONATAS CRISTIAN RODRIGUES; LEANDRO EMIDIO TEIXEIRA; LIDIA YAMAMOTO; THELMA SUELY OKAY. PRELIMINARY REPORT ON THE PUTATIVE ASSOCIATION OF IL10 -3575 T/A GENETIC POLYMORPHISM WITH MALARIA SYMPTOMS. Revista do Instituto de Medicina Tropical de São Paulo, v. 58, p. -, 2016.

DOMINGUES, WILSON; KANUNFRE, KELLY APARECIDA; RODRIGUES, JONATAS CRISTIAN; TEIXEIRA, LEANDRO EMIDIO; YAMAMOTO, LIDIA; OKAY, THELMA SUELY. PRELIMINARY REPORT ON THE PUTATIVE ASSOCIATION OF IL10-3575 T/A GENETIC POLYMORPHISM WITH MALARIA SYMPTOMS. Revista do Instituto de Medicina Tropical de São Paulo, v. 58, 2016. Web of Science Citations: 2.

SHIMOKAWA, PAULO TADASHI; TARGA, LILIA SPALETA; YAMAMOTO, LIDIA; RODRIGUES, JONATAS CRISTIAN; KANUNFRE, KELLY APARECIDA; OKAY, THELMA SUELY. HLA-DQA1/B1 alleles as putative susceptibility markers in congenital toxoplasmosis. VIRULENCE, v. 7, n. 4, p. 456-464, 2016. Web of Science Citations: 2.

TEIXEIRA, LEANDRO EMIDIO; KANUNFRE, KELLY APARECIDA; SHIMOKAWA, PAULO TADASHI; TARGA, LILIA SPALETA; RODRIGUES, JONATAS CRISTIAN; DOMINGUES, WILSON; YAMAMOTO, LIDIA; OKAY, THELMA SUELY. The performance of four molecular methods for the laboratory diagnosis of congenital toxoplasmosis in amniotic fluid samples. Revista da Sociedade Brasileira de Medicina Tropical, v. 46, n. 5, p. 584-588, SEP-OCT 2013. Web of Science Citations: 14.