Susceptibility for stroke in children with sickle cell anemia

ABSTRACT

This study was done to detect cases of silent and clinically overt strokes in children with sickle cell anemia [SCA] either in the steady or thrombotic crisis states as wed as to evaluate the role of some laboratory and genetic parameters as predisposing factors for development of stroke including fibrin peptide-A [FPA], thrombin-antithrombin Ill complex [TAT], fibrin degradation products [D-dimer], platelet endothelial cell adhesion molecule-I [PECAM-1] and molecular genetic study of the angiotensin converting enzyme [ACE] gene polymorphism. The study included 20 children with SCA diagnosed clinically, hematologically and confirmed by hemoglobin electrophoresis. They were divided in to group I; included 10 children with SCA in the steady state and group II; included 10 SCA children in thrombotic crisis. Another 10 healthy children with matched age and sex were taken as a control group. A!! the studied groups were subjected to full clinical examination, measurements of FPA, TAT, D-dimer and PECAM-1 as we1 as molecular genetic study of the ACE gene polymorphism. Brain computed axial tomography [CT] scan and/or magnetic resonance imaging [MRI] as well as electroencephalographic studies [EEG] were done only for patient groups. Results showed that silent ischemic brain infarction evidenced only by CT scan and/or MRI was present in one patient in-group I [10%] and one patient in-group II [10%]. On the other hand, two patients in-group II [20%] were presented by clinically overt strokes. Thus, according to the presence or absence of stroke [either silent or clinically overt] there were stroke group [4 children] and non-stroke group [16 children]. Laboratory results showed that the levels of FPA, TAT, D-dimer and PECAM-1 were significantly elevated in SCA patients both in the steady and crisis states as compared to control, with more evident significant elevation in group II [thrombotic crisis] as compared to group I [steady state], Stroke group showed significant elevation in all the studied parameters; FPA, TAT, D-dimer and PECAM-I as compared with non-stroke group. The molecular study results showed that the frequencies of both DD genotype and D allele of ACE gene in the thrombotic crisis were significantly higher than in the control group and that all stroke group children are of DD genotype. In conclusion; significant increase in FPA, TAT, D- dimer and PECAM-1 levels as well as the presence of ACE D allele o! the ACE gene are significant predisposing factors for stroke in children with SCA either in the steady or in the crisis states which my recommend regular follow-up by thorough neurological examination and neuro-imaging studies for early detection of silent brain infarction as well as the preventive use of effective therapies as repeated bloi3d transfusion and bone marrow transplantation