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CTLA‐4 exon 1 polymorphism in patients with autoimmune blood disorders
Author(s) -
Pavkovic Marica,
Georgievski Borce,
Cevreska Lidija,
Spiroski Mirko,
Efremov Dimitar G.
Publication year - 2003
Publication title -
american journal of hematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.456
H-Index - 105
eISSN - 1096-8652
pISSN - 0361-8609
DOI - 10.1002/ajh.10278
Subject(s) - autoimmune hemolytic anemia , immunology , chronic lymphocytic leukemia , allele , medicine , ctla 4 , autoimmunity , autoimmune disease , thrombocytopenic purpura , t cell , immune system , leukemia , biology , antibody , gene , genetics
Abstract CTLA‐4 is a CD28 homologue that plays an important role in negative regulation of T‐cell responses. Its transient expression on the surface of activated T cells antagonizes the activating signals and terminates the T‐cell response. An A to G polymorphism at position 49 of the CTLA‐4 first exon has recently been associated with several autoimmune disorders. In the present study we have examined the prevalence of the A and G alleles of the CTLA‐4 gene in 50 patients with autoimmune hemolytic anemia (AIHA), of which 20 had idiopathic AIHA and 30 had AIHA and chronic lymphocytic leukemia (CLL), and in 60 patients with immune thrombocytopenic purpura (ITP). Control subjects were 100 healthy individuals and 100 CLL patients without clinical evidence for an autoimmune disease. The G allele was present at a significantly higher frequency among the patients with AIHA ( P = 0.003), whereas no difference was observed between patients with ITP and controls. The G allele frequency was highest among CLL patients who had developed AIHA. The obtained data indicate that the G allele of CTLA‐4 predisposes to the development of AIHA, particularly among patients with CLL. Am. J. Hematol. 72:147–149, 2003. © 2003 Wiley‐Liss, Inc.