Natural Anticoagulant Deficiencies Research Articles

Prothrombotic states in young people with idiopathic stroke. A prospective study.

Although 4% of cerebral infarcts in the young can be attributed to hematologic disturbances that predispose to thrombosis, the frequency of cerebral infarcts caused by prothrombotic states is not known. Recently, the association between cerebral infarction and deficiencies of elements of the natural anticoagulant system has been recognized. Thirty-six consecutive patients under 40 years of age with cerebral infarction of undetermined cause were prospectively studied. Quantitation of natural anticoagulants was done at least 3 months after the cerebral infarction. The following activity tests were performed, all by the chromogenic method: antithrombin III, protein C, plasminogen, tissue plasminogen activator, and inhibitor of tissue plasminogen activator. Protein S was quantified by the Laurell rocket method. All patients underwent a complete cardiological examination, including two-dimensional echocardiography, as well as four-vessel cerebral angiography. Some patients were also studied by transesophageal echocardiography. Of 36 patients, 17 were male, with a mean age of 28 years. Mean age for women was 25 years. Nine patients (25%; 5 women, 4 men) had a deficiency of one natural anticoagulant and constituted group I. In these patients, isolated protein S deficiency was detected in five cases (13.8%); in one case, we observed the association between protein S deficiency and antiphospholipid antibodies; and deficiency of protein C was seen in one case (2.7%), of antithrombin III in one case (2.7%), and of plasminogen in one case (2.7%). Instances of cerebral infarction without natural anticoagulant deficiency (group II) included 12 women and 15 men. There were no differences in clinical and radiological findings between the two groups. Considering the importance of prothrombotic state, especially caused by deficiency of protein S, in the development of cerebral infarcts, we suggest that it should be looked for in every young patient affected by this pathological entity and in whom no etiologic factors can be determined.

Clinical Manifestations and Management of Inherited Thrombophilia: Retrospective Analysis and Follow-up after Diagnosis of 238 Patients with Congenital Deficiency of Antithrombin III, Protein C, Protein S

The clinical history of 238 patients with inherited thrombophilia (AT III = 94, PC = 103, PS = 41) was analyzed retrospectively at diagnosis and in the follow-up period after diagnosis. At diagnosis 129 patients (54%) had suffered from thrombosis, with a recurrence rate of 48%. The most frequent onset manifestation was deep vein thrombosis of lower limbs (58%). Thrombotic history started before 40 in 80% of the cases. Forty-nine percent of the venous thromboses were preceded by a triggering event, in most cases pregnancy (17%) and surgery (12%). After diagnosis, follow-up lasted a total of 1,113 pt-years. A policy of short-term prophylaxis during risk situations for all patients and long-term prophylaxis in symptomatic patients failed to prevent venous thrombotic episodes (diagnosed by objective methods) in 4 previously asymptomatic subjects and recurrence in 7 previously symptomatic subjects. After knowledge of the patients' diagnosis the incidence of venous thrombosis/100 pt-years was reduced as compared before diagnosis as total episodes (onset+recurrencies) (1.0 vs 1.9), onset episodes (0.7 vs 1.3) and recurrent episodes (1.3 vs 4.8), even though the differences were not statistically significant. However most of the venous thromboses occurred at a more advanced age (67% after 40 years) and without any apparent cause (83%), at significant variance with the period preceding the diagnosis; in particular the incidence of venous thrombotic onset in patients younger than 40 passed from 1.3/100 pt-years to 0.2/100 pt-years. In 6 recurrences after diagnosis a poor compliance for antithrombotic treatment was recognized.(ABSTRACT TRUNCATED AT 250 WORDS)

The investigation of patients with retinal vascular occlusion

The investigation of patients with retinal artery occlusion, retinal vein occlusion and cotton wool spots is discussed. The majority are due to either emboli or atheroma and occur in elderly patients. A full clinical history and examination remain the essential part of the investigation but the ophthalmologist must select patients in whom further investigation is warranted. The recent recognition of the importance of antiphospholipid antibodies and natural anticoagulant deficiency states in the pathogenesis of thrombosis has identified a group of young people in whom specific therapy may be indicated.