Inherited protein S deficiency
Introduction
Introduction to hereditary protein S deficiency Hereditary protein S deficiency is an autosomal dominant susceptibility to thrombosis, which is homozygous and heterozygous. It is clinically heterozygous for type I, mainly characterized by venous thrombosis. basic knowledge The proportion of illness: 0.003% Susceptible people: no special people Mode of infection: non-infectious complication:
Cause
Causes of hereditary protein S deficiency
(1) Causes of the disease
In the etiology of venous thrombosis, genetic PS deficiency accounts for about 5%, and autosomal dominant protein S activity and content are reduced.
(two) pathogenesis
Since PS is a cofactor of protein C (PC), its deficiency mainly leads to a decrease in the activity of PC inactivating factor Va and factor VIIIa, resulting in venous thrombosis.
Prevention
Hereditary protein S deficiency prevention
Oral anticoagulants prevent thrombosis and recurrence.
Complication
Hereditary protein S deficiency complications Complication
Generally no complications.
Symptom
Hereditary protein S deficiency symptoms Common symptoms Venous thrombosis Pulmonary embolism Skin necrosis
Therefore, the clinical manifestations of this disease are similar to PC deficiency. Thrombosis is more common with venous thrombosis. Venous thrombosis mainly involves the lower extremity vein, and may also involve visceral veins. It is more common than PC deficiency, such as renal vein and spleen. Intravenous, mesenteric vein, etc., 30% of patients with pulmonary embolism, this disease is less common arterial thrombosis, and PC deficiency, can have neonatal fulminant purpura and dicoumarin skin necrosis and other characteristics.
Examine
Examination of hereditary protein S deficiency
1. Decreased free PS activity.
2. The free PS content of some PS content decreased or normal.
According to the condition, clinical manifestations, symptoms, signs, choose to do hematuria, routine B-ultrasound, CT, X-ray and other tests.
Diagnosis
Diagnosis and identification of hereditary protein S deficiency
diagnosis
1. Diagnosis method
The diagnosis depends on laboratory tests, mainly to determine the activity and content of PS. The PS activity is usually determined by coagulation method, and the PS content is usually determined by ELISA or latex method.
2. Diagnostic criteria and basis
There is no uniform diagnostic standard. The diagnostic criteria developed in the book "Diagnostic and Efficacy Standards for Hematological Diseases" edited by Zhang Zhinan are based on the relevant references at home and abroad.
(1) thrombosis or asymptomatic: venous thrombosis is more common, the site in the femoral vein, iliac vein, splenic vein, mesenteric vein or pulmonary embolism, arterial thrombosis is rare, in young patients.
(2) Autosomal dominant inheritance.
(3) homozygous and heterozygous: homozygous plasma PS content decreased more severe than heterozygous.
(4) Plasma total PS and/or free PS content decreased or normal, related to type.
(5) Decreased plasma PS activity.
3. Diagnostic evaluation
(1) In Europe and the United States, the cause of venous thrombosis is mainly APC-R caused by factor V Leiden mutation, but in Chinese population, the incidence of APC-R is extremely low, and is not caused by factor V Leiden mutation, vein The cause of thrombosis is mainly anticoagulant protein defects, including antithrombin, PC, PS defects, especially the incidence of PS deficiency. The study of Peking Union Medical College Hospital Bai Chunmei suggests that PS in patients with venous thrombosis Defects accounted for 14.9%, and Taiwan and Hong Kong were 32.9% and 21.3%, respectively. This suggests that the cause of venous thrombosis in Chinese population is different from that in Europe and the United States. PS defects may be the most common cause.
(2) Similar to hereditary PC deficiency, most patients with hereditary PS deficiency do not find thrombus in their lifetime, so the diagnosis of medical history and family history is relatively small. The diagnosis mainly needs to pass laboratory tests. Therefore, the experimental method must be reliable. It is best to make a diagnosis based on the results of 2 blood tests. Each laboratory should establish its own normal value. It is not appropriate to copy the normal reference values published in the literature or other laboratories.
(3) Determination of PS activity Mainly measured free: PS activity, generally using coagulation method, its main disadvantage is poor reproducibility, affected by FV Leiden mutation and freeze-thaw of specimen can produce pseudo-reduction of PS activity, in the analysis results It should be considered. In addition, like PC, PS is also a vitamin K-dependent protein. Therefore, oral warfarin also affects its actual level.
(4) It can be seen from the classification criteria that the total PS content, free PS content and PS activity are different in each type, so these three parameters should be measured simultaneously in the diagnosis of this disease.
Differential diagnosis
Diagnosis of hereditary PS deficiency requires first exclusion of various secondary PS defects such as liver disease, kidney disease, diabetes, acute inflammation, DIC, pregnancy, and the use of contraceptives, warfarin, asparaginase and estrogen. Can be reduced, acute inflammation and DIC, PS content and activity are reduced.
Hereditary PS deficiency should also be differentiated from other anticoagulant (anti-thrombin, PC) defects and anti-activated protein C (APC-R). In addition, some patients may be associated with protein C deficiency, APC-R, Excessive PAI-1, or associated with anti-cardiolipin antibodies, should be noted.
