Impact of IL-1Ra Gene Polymorphism on the Etiology and Fate of Disease in Children with Immune Thrombocytopenic Purpura

Abstract

Background. Immune thrombocytopenic purpura (ITP) is considered to be one of the common childhood autoimmune diseases, and the current study was initiated to study the effect of various factors, particularly interleukin 1 receptor antagonist (IL-1Ra) gene polymorphism, on the course of the disease. Methods. The current case-control study involved 60 newly diagnosed children presented with ITP (also included 60 age- and sex-matched healthy children). All enrolled individuals had complete blood count and molecular study to determine the polymorphic state of IL-1Ra gene using conventional polymerase chain reaction. Results. Sixty patients with ages 1-14 years and having a male/female ratio of 1 : 1.61 were enrolled in the current study. Forty-five children (75%) recovered within the first year, and 15 (25%) children developed chronic ITP. IL-1Ra $\ast$ 2 variant was found to be significantly associated with control groups ( $P=0.011$ ), while IL-1Ra $\ast$ 3 was significantly associated with patients ( $P=-0.0163$ ). Other factors having significant association with the remission rate include a previous history of immunization ( $P<0.0001$ ) and the symptoms at presentation ( $P=0.0009$ ). Conclusions. The current study revealed a significant correlation of IL-1Ra gene polymorphism to the etiology and the course of the disease.