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 à 01:03 and à 03:02 alleles could confer susceptibility (ORD 3.06, p D 0.0002 and ORD 9.60, pD 0.0001, respectively) as they were more frequent among infected fetuses. Regarding the HLA-DQB1 region, the à 05:04 allele could confer susceptibility (OR D 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 D 9.37, pD0.011). 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.

Toxoplasma gondii: Biological Parameters of the Connection to Schizophrenia

“…In the case of Toxoplasma, studies of congenital infection have implicated a number of tolllike receptors and other immune response genes relating to increased risk. 74,75 In regards to infection in later life, a population study of 1227 individuals from a Mexican American community in Texas found that seropositivity to Toxoplasma was heritable with a heritability factor (H2) of 0.21 ± 0.05 (P < .001). However, specific polymorphisms significantly associated with Toxoplasma seropositivity were not identified.…”

HLA class I and II associations with common enteric pathogens in the first year of life

“…The strength of this association matches several of our identified protective associations. In a congenital study examining 122 foetuses for toxoplasmosis where HLA class II molecules play a crucial role in immunity, HLA-DQA1*01:03 ( P -value = 0·0002 [Chi-square test], OR = 3·1) and HLA-DQA1*03:02 ( P -value = 0·0001 [Chi-square test], OR = 9·6) were found to be associated with increased susceptibility to congenital toxoplasmosis [40] . The magnitude of the HLA-DQA1*03:02 association is similar to our HLA-B*35:05 association with typical EPEC but is far stronger than any other HLA association identified.…”

Human toxoplasmosis in Mozambique: gaps in knowledge and research opportunities

“…Studies conducted in several countries of Southeast Africa, such as Zambia, South Africa, Eswatini (former Swaziland), Zimbabwe, Angola, Namibia, Tanzania, Madagascar, Uganda, Kenya, Ethiopia, and Mozambique, indicate prevalence of T. gondii infection that ranges from 4% to 93% in the general population [11][12][13]. Signs, symptoms, and the severity of T. gondii infection differs according to the immune status of the individual, the age in which the infection was acquired, and the genotype of the parasite involved [2,3,[14][15][16]. In immunosuppressed patients due to human immunodeficiency virus (HIV) or immunosuppressive therapy, toxoplasmosis is considered a life-threatening parasitic disease.…”