Paraoxonase-1 (PON-1) L/M 55 gene polymorphism in the cases of idiopathic thrombocytopenic purpura

Idiopathic thrombocytopenic purpura (ITP), which is an autoimmune, selflimiting characterized by an increase in the destruction of thrombocytes in circulation, is the most common cause of acquired childhood thrombocytopenia. It has been considered that getting over viral infections cause to trigger the body to produce antibody destroy the thrombocytes in the pathogenesis of idiopathic thrombocytopenic purpura.Oxidative damage plays a role the pathogenesis of autoimmune disorders. Oxidative stres and free-radicals could be responsible the pathogenesis and prognosis of ITP. Paraoxonase-1 (PON-1) is an esther- hydrolase enzyme which has antioxidative feature and synthetised by liver. Two genetic polymorphisms were detected in human serum PON-1 enzyme. Of first appears in case of 55 Met(M)/Leu(L) polymorphism.In this study, it had investigated that the role of paraoxogenase- 1 M/L gene polymorphisim in ethiopathogenesis of ITP, course of disorder and its effects of the therapy.Fifty-one patients with acute ITP, fifteen patients with cronical ITP and sixty healty controls were investigated. For individuals with acute, chronical ITP and healty group, the frequency of LL genotype were founded as 19.6%, 40% and 2%, respectively, meanwile the percentages for LM genotype were 60.8%, 46.7% , 65% and of MM genotype were 19.6%, 13.3% ve 8.3%. Our result indicate that the frequency of LL genotype in chronical ITP group is statistically and significiantly higher than those of acute ITP group and controls (p<0.05).The frequency of MM genotype in controls was lower than the MM frequencies of ITP patient (p<0.05). Having been comparing data, the frequency of L allel in chronical ITP group were statistically higher (p<0.05). For acute ITP group, the frequency of M allel were statistically higher than the frequency of chronical group.Consequently, paraoxonase- 1 L/M 55 gene polymorphism in the cases of ITP displayed differences when compared those of controls. This differency might create a susceptibility in some patiens against disorder. It could effect course of disorder, even might change respons of treatment. It was founded that individuals who has LL genotype tend to be chronic.Key words: Idiopathic thrombocytopenic purpura, paraoxonase, polymorphisim, methylprednisolone, intravenous immunoglobuline.