Background Antiphospholipid syndrome (APS) is an autoimmune disease characterised by recurrent arterial or venous thrombosis, pregnancy morbidity and the persistence of positive antiphospholipid antibodies (aPLA). The selectins are cell adhesion molecules that mediate the interaction among leukocytes, activated platelets and endothelial cells. P-selectin, which can be identified as soluble form in plasma, intercedes the attachment and rolling of leukocytes on activated endothelial cells, and is involved in the recruitment of leukocytes to thrombi.
Objectives We aimed to investigate whether P-selectin polymorphisms are associated with thrombosis in patients with APS.
Methods Fourty adult patients with APS and 40 healthy subjects as controls with no history of thrombosis or autoimmune diseases were included into the study. The diagnosis and classification of APS were based on the report of an international workshop. The subjects participating in the study had no systemic lupus erythematosus and the risk factor such as hypertension or hyperlipidemia for thrombosis. Genomic DNA was extracted from citrated blood samples of all subjects. Three single nucleotide polymorphisms associated with P-selectin coding region (S290N, c.1087G>A; D562N, c.1902G>A; T715P, c.2363A>C) were assessed.
Results There were 26 APS (65%) patients with thrombosis involved vein, artery, vein and artery together respectively; 12 (46%), 10 (38%) and 4 (15%). The number of patients without thrombosis was 14 (35%). The mean age of patients (92% female) was 39,4±9,5. The frequency of D562N-DN genotype was significantly higher in patients with APS than healthy controls (p: 0,003). The frequency of this genotype was significantly higher in patients with APS with thrombosis compared with patients with no thrombosis (p:0,03). D562N-NN genotype was found at a higher frequency in patients with APS than healthy controls (p:0,004). The frequency of D562N-NN genotype was comparable between patients without thrombosis and controls (p:0,21). On the other hand, S290N and T715P polymorphisms were similar in all subjects (Table). No relationship was found between APLA, thrombocytopenia or fetal loss and P selectin polymorphisms.
Conclusions Our results suggest that D562N polymorphism DN genotype of P-selectin is associated with an increased risk of thrombosis in patients with APS. NN genotype of the same polymorphism might be protective for thrombosis in those patients. The effect of D562N polymorphism on soluble P-selectin levels will be studied in the next step.
Disclosure of Interest None Declared