Biomedical subjects

Sandrine Marquet

Publications and source records attributed to Sandrine Marquet.

5 recordsLinked to original sources

PubMed2006

Alleles 308A and 238A in the tumor necrosis factor alpha gene promoter do not increase the risk of severe malaria in children with Plasmodium falciparum infection in Mali.

The hypothesis that tumor necrosis factor (TNF) aggravates malaria in children is supported by observations that TNF polymorphisms and high TNF levels have been associated with cerebral malaria. Nevertheless, severe malaria was not associated with polymorphisms located at positions -308A and -238A in the TNF alpha gene promoter or with a high TNF level in plasma in children from Bamako, Mali.

Alleles↗

PubMed2006

IL13RA2 gene polymorphisms are associated with systemic sclerosis.

OBJECTIVE: To investigate the influence of genetic variability on the phenotypic expression of systemic sclerosis (SSc), by testing possible associations between single nucleotide polymorphisms (SNP) in IL13RA1 and IL13RA2 genes and SSc in a Caucasian population. METHODS: As IL13RA1 and IL13RA2 are located on the X chromosome and SSc occurs far more frequently in women than in men, only women were genotyped. The study group comprised 97 women with SSc, 36 with diffuse (dcSSc) and 61 with limited (lcSSc) cutaneous forms of disease, and 109 healthy controls. Patients and controls were Caucasian. We investigated 4 SNP in IL13RA1 and 3 in IL13RA2 by polymerase chain reaction amplifications and enzymatic digestion or primer extension reactions and denaturing high-performance liquid chromatography. RESULTS: We detected an association between IL13RA2 rs638376 and patients with SSc [p = 0.004, odds ratio (OR) = 1.85, confidence interval (CI) 1.22-2.74, p corr = 0.02], as well as with dcSSc in that subgroup of patients (p = 0.01, OR 2.22, 95% CI 1.27-3.89, p corr = 0.05). The IL13RA2 rs638376G allele frequency was higher in patients with SSc (51.6%) than in controls (36.4%, p = 0.003, OR 1.86, 95% CI 1.24-2.79, p corr = 0.015) and in the subgroup with dcSSc (57.6%) than in controls (36.4%, p = 0.003, OR 2.37, 95% CI 1.35-4.15, p corr = 0.015). One other IL13RA2 SNP was only associated with the dcSSc subgroup: the IL13RA2 rs5946040G allele was more common in patients with dcSSc (33.8%) than in controls (17%, p = 0.004, OR 2.5, 95% CI 1.36-4.60, p corr = 0.02). CONCLUSION: Our data suggest that IL13RA2 gene polymorphisms may be involved in susceptibility to SSc. Further studies are under way to show that they contribute to disease.

Adult↗

PubMed2006

Evaluation of interleukin 13 polymorphisms in systemic sclerosis.

Systemic sclerosis (SSc) is a multisystem disease of unknown etiology. It is characterized by excessive cutaneous and visceral fibrosis, damage to small blood vessels, and production of autoantibodies. Interleukin-13 (IL-13) has been shown to be involved in abnormal fibrosis in other diseases. Therefore, we have evaluated its possible involvement in SSc. We analyzed four IL13 gene polymorphisms, rs1800925 (IL13-1055), rs20541 (Arg130Gln), rs847, and rs2243204 in 107 unrelated SSc patients (40 patients having diffuse cutaneous form and 67 patients having limited cutaneous form) and in 170 controls. All subjects were Caucasians. In the total patient population and in the diffuse cutaneous subset, we observed an association between two IL13 polymorphisms, IL13 rs1800925 (IL13-1055), and IL13 rs2243204, and disease (p=0.03-0.04). The IL13 rs2243204T allele was more common in SSc patients (p=0.01, OR=2.3 CI 1.21-4.38) and in the diffuse cutaneous form (p=0.01, OR=2.95, CI 1.35-6.49) than in control subjects. Our result supports the suggestion that polymorphisms in IL13 are associated to SSc and skin fibrosis process. However, further studies on larger and independent population and functional analyses are needed to confirm these findings.

Aged↗

PubMed2005

Evidence that interferon-gamma plays a protective role during cerebral malaria.

BACKGROUND: The pathogenic mechanisms of cerebral malaria (CM) are unclear but are thought to involve cytokine-mediated inflammation enhanced by parasite sequestration in the brain microcirculation. The role that interferon (IFN)-gamma could play that would enhance inflammation but also reduce parasitemia is unclear. METHODS: Plasma IFN-gamma concentrations were measured by enzyme-linked immunosorbent assay in 96 children with CM and 40 children with uncomplicated malaria (UM) who had been recruited from Gabriel Toure Hospital (Bamako, Mali). We investigated the relationship between IFN- gamma concentrations and disease by nonparametric analysis. Polymorphisms in IFNG were characterized by restriction enzyme analysis or size-determination electrophoresis. Associations between polymorphisms and CM were evaluated by the family-based association test on 240 families. RESULTS: During episodes of malaria, IFN-gamma concentrations were lower in children with CM than in children with UM (P = .007). IFNG-183T (P = .009) and IFNG-183G/T (P = .013) were found to be less frequent than expected in children with CM. A trend toward association was also observed between IFNG(CA)14/(CA)14 (P = .073) and CM. The IFNG-183G/T and IFNG(CA)14/(CA)14 genotypes were more frequent in children with UM than in children with CM (odds ratio, 0.30 and 0.34, respectively). CONCLUSIONS: The low plasma IFN- gamma concentrations in children with CM and the associations between a reduced risk of CM and (1) the IFNG-183T allele (which increases gene transcription) and (2) the IFNG-183G/T genotype are consistent with the concept that IFN-gamma protects against CM.

Animals↗

PubMed2004

Interleukin-13 in the skin and interferon-gamma in the liver are key players in immune protection in human schistosomiasis.

Immunity against schistosomes includes anti-infection immunity, which is mainly active against invading larvae in the skin, and anti-disease immunity, which controls abnormal fibrosis in tissues invaded by schistosome eggs. Anti-infection immunity is T-helper 2 (Th2) cell-dependent and is controlled by a major genetic locus that is located near the Th2 cytokine locus on chromosome 5q31-q33. Mutations in the gene encoding interleukin (IL)-13 that decrease or increase IL-13 production account, at least in part, for that genetic control. In contrast, protection against hepatic fibrosis is dependent on interferon (IFN)-gamma and is controlled by a major genetic locus that is located on 6q23, near the gene encoding the IFN-gamma receptor beta chain. Mutations that modulate IFN-gamma gene transcription are associated with different susceptibility to disease. These data indicate that IL-13 in the skin and IFN-gamma in the liver are key players in protective immunity against schistosomes. These roles relate to the high anti-fibrogenic activities of IFN-gamma and to the unique ability of IL-13 in Th2 priming in the skin and in the mobilization of eosinophils in tissues. The coexistence of strong IFN-gamma and IL-13-mediated immune responses in the same subject may involve the compartmentalization of the anti-schistosome immune response between the skin and the liver.

Animals↗