title: Lack of impact of cytotoxic T-lymphocyte antigen 4 gene exon 1 polymorphism on susceptibility to or clinical course of egyptian childhood immune thrombocytopenic purpura.
abstract: Dysfunctional T-lymphocyte immunity plays an important role in the pathophysiology of immune thrombocytopenic purpura (ITP). Cytotoxic T-lymphocyte antigen 4 (CTLA-4)-a surface marker expressed on T regulatory cells and activated T lymphocytes-is a negative modulator of T-cell responses. Polymorphisms of the CTLA-4 may alter the level of antigen expression and hence may influence immune regulation. The study aimed to evaluate the possible contribution of CTLA-4 exon 1 49 A>G polymorphism to the pathogenesis of ITP and its relation to age of disease onset, clinical course, and response to therapy. Genotyping of CTLA-4 exon 1 49 A>G was performed in 100 pediatric patients with ITP and 259 healthy individuals by polymerase chain reaction-restricted fragment length polymorphism. No significant differences existed in genotype or allele distributions between patients and controls for the studied polymorphism. Comparable genotypes and allele frequencies were obtained between the 2 groups after their stratification by age of disease onset, clinical course, or response to therapy. In conclusion, CTLA-4 exon 1 49 A>G polymorphism is not associated with susceptibility to ITP in the Egyptian population; neither it affects the clinical picture of the disease.
authors.affiliation: Department of Clinical and Chemical Pathology, Faculty of Medicine, Cairo University, Giza, Egypt emanrradwan@gmail.com.
authors.forename: Eman Roshdy
authors.initials: ER
authors.lastname: Radwan
authors.affiliation: Department of Paediatric Haematology, Faculty of Medicine, Cairo University, Giza, Egypt.
authors.forename: Rania L M
authors.initials: RL
authors.lastname: Goda
mesh_terms: D000293:Adolescent; D060908:CTLA-4 Antigen / Q000096:biosynthesis / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D004534:Egypt; D005091:Exons; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007223:Infant; D008297:Male; D011110:Polymorphism, Genetic; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000235:genetics* / Q000378:metabolism
chemical_list: D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human
keywords: CTLA-4; CTLA-4 exon 1 49 A>G polymorphism; immune thrombocytopenic purpura