Detecting anti-prothrombin antibodies in young women with acute ischemic stroke

Abstract

Prothrombin (PT) is a target for antibodies with lupus anticoagulant (LA) activity. Anti-prothrombin antibodies (aPT) were recently identified as antibodies directed toward a phospholipid-binding protein. aPT are a new serologic marker of antiphospholipid syndrome. The objective was to detect aPT in a group of 46 patients with acute ischemic stroke in order to correlate their presence with clinical diagnosis, laboratory and neuroradiological findings. We tested aPT, lupus anticoagulant (LA), anticardiolipin (aCL), and anti-beta2-glycoprotein I antibodies (anti-bbeta2-GPI) in 46 young women with acute ischemic stroke aged 34-45 years and 43 patients with nonischemic neurologic diseases and 141 normal controls. Anti-prothrombin antibodies were detected by calcium-containing aPT ELISA, aCL and anti-beta2-GPI by ELISA. All samples were screened using the activated partial thromboplastin time (aPTT); the dilute Russell viper venous time (dRVV) coagulation test was performed. The results were statistically analyzed. Anti-prothrombin antibodies were found in 26 (57%) of 46 stroke patients. Out of 43 patients with nonischemic neurological disorders, 2 (4.18%) were positive for aPT. aPT were detected in one (0.70%) of the normal controls. Ten stroke patients (21%) were positive for IgG aPT only, 9 stroke patients (18.2%) for IgM aPT only, and 8 stroke patients (16.9%) for both IgG and IgM isotypes of aPT. Two nonischemic neurological disorders patients (4.18%) presented IgM isotype of aPT. Patients with ischemic stroke presented aPT much more frequently than the healthy controls (OR 182.00 [95% CI 23.382-1416.6]. p < 0.0001). Patients with ischemic stroke presented aPT much frequently than the nonischemic neurological disorders patients (OR 26.650 [95% CI 5.743-123.66], p < 0.0001). When IgG or IgM aPT were considered separately, they were more frequently found in patients with ischemic stroke than in healthy control group (OR 38.889 [95% CI 4.817-313.95], p < 0.0001) and (OR 34.054 [95% CI 4.178-277.5], p < 0.0001), respectively. Simultaneous positive titers for both isotypes of aPT (IgG and IgM) were more frequently found in patients with ischemic stroke than in healthy control group (OR 29.474 [95% CI 3.573-243.12], p < 0.0001). Eleven stroke patients (43%) were negative for aCL, LA and anti-beta2-GPI, but positive for aPT (OR 0.03287 [95% CI 0.001794-0.6022], p < 0.001). aCL, LA and anti-beta2-GPI were not found both in nonischemic neurological disorders patients and in healthy controls.