title: HLA-DQA1/B1 alleles as putative susceptibility markers in congenital toxoplasmosis.
abstract: Host and parasite genotypes are among the factors associated with congenital toxoplasmosis pathogenesis. As HLA class II molecules play a key role in the immune system regulation, the aim of this study was to investigate whether HLA-DQA1/B1 alleles are associated with susceptibility or protection to congenital toxoplasmosis. One hundred and twenty-two fetuses with and 103 without toxoplasmosis were studied. The two study groups were comparable according to a number of socio-demographic and genetic variables. HLA alleles were typed by PCR-SSP. In the HLA-DQA1 region, the allele frequencies showed that *01:03 and *03:02 alleles could confer susceptibility (OR= 3.06, p = 0.0002 and OR= 9.60, p= 0.0001, respectively) as they were more frequent among infected fetuses. Regarding the HLA-DQB1 region, the *05:04 allele could confer susceptibility (OR = 6.95, p < 0.0001). Of the 122 infected fetuses, 10 presented susceptibility haplotypes contrasting with only one in the non-infected group. This difference was not statistically significant after correction for multiple comparison (OR = 9.37, p=0.011). In the casuistic, there were two severely damaged fetuses with high parasite loads determined in amniotic fluid samples and HLA-DQA1 susceptibility alleles. In the present study, a discriminatory potential of HLA-DQA1/B1 alleles to identify susceptibility to congenital toxoplasmosis and the most severe cases has been shown.
authors: a Laboratory of Seroepidemiology and Immunobiology, Institute of Tropical Medicine, University of São Paulo , São Paulo , Brazil.
authors: Paulo Tadashi
authors: PT
authors: Shimokawa
authors: a Laboratory of Seroepidemiology and Immunobiology, Institute of Tropical Medicine, University of São Paulo , São Paulo , Brazil.
authors: Lília Spaleta
authors: LS
authors: Targa
authors: a Laboratory of Seroepidemiology and Immunobiology, Institute of Tropical Medicine, University of São Paulo , São Paulo , Brazil.
authors: Lidia
authors: L
authors: Yamamoto
authors: a Laboratory of Seroepidemiology and Immunobiology, Institute of Tropical Medicine, University of São Paulo , São Paulo , Brazil.|b LIM 48- Laboratory of Immunology, Department of Infectious and Parasitic Diseases, School of Medicine, University of São Paulo , São Paulo , Brazil.
authors: Jonatas Cristian
authors: JC
authors: Rodrigues
authors: a Laboratory of Seroepidemiology and Immunobiology, Institute of Tropical Medicine, University of São Paulo , São Paulo , Brazil.|b LIM 48- Laboratory of Immunology, Department of Infectious and Parasitic Diseases, School of Medicine, University of São Paulo , São Paulo , Brazil.
authors: Kelly Aparecida
authors: KA
authors: Kanunfre
authors: a Laboratory of Seroepidemiology and Immunobiology, Institute of Tropical Medicine, University of São Paulo , São Paulo , Brazil.
authors: Thelma Suely
authors: TS
authors: Okay
mesh_terms: D000328:Adult; D000483:Alleles; D000653:Amniotic Fluid / Q000469:parasitology; D005260:Female; D005333:Fetus / Q000469:parasitology / Q000473:pathology; D005787:Gene Frequency; D005819:Genetic Markers; D020022:Genetic Predisposition to Disease; D005838:Genotype; D059848:HLA-DQ alpha-Chains / Q000235:genetics*; D059866:HLA-DQ beta-Chains / Q000235:genetics*; D006239:Haplotypes; D006801:Humans; D059208:Parasite Load; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000469:parasitology; D014122:Toxoplasma / Q000276:immunology / Q000472:pathogenicity; D014125:Toxoplasmosis, Congenital / Q000235:genetics* / Q000276:immunology; D055815:Young Adult
chemical_list: D005819:Genetic Markers; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; C069050:HLA-DQA1 antigen; C069051:HLA-DQB1 antigen
keywords: Congenital toxoplasmosis; Genetic polymorphism; Genetic susceptibility; HLA alleles; polymerase chain reaction