[Recurrent thromboembolism disclosing protein C deficiency. Apropos of a case with familial investigation].
Every thromboembolic manifestation, especially in young subjects, calls for an aetiological study in which haemostasis is evaluated primarily with assays of physiological coagulation inhibitors: protein C, protein S and antithrombin III. Protein C deficiency is found in 6 to 7% of thromboembolic manifestations. We report the case of a 21-year old man who had phlebitis followed by pulmonary embolism without facilitating factors. Protein C level was 50% of normal value (0.50 IU/ml). The patient received heparin, subsequently replaced by oral anticoagulants after a long period of overlap between the two treatments. The outcome was favourable. Family investigation yielded a history of thromboembolic accidents in several members of the family, some of whom were protein C deficient (50% of normal value). Protein C synthesis is vitamin K-dependent. Protein C deficiency is transmitted as an autosomal dominant trait. Normal values range from 0.65 to 1.35 IU/ml. Clinically, 25% of the patients are said to be asymptomatic. The first thrombotic accidents occur in young subjects (mean age 29 +/- 14 years). Several points emerge from this case: full evaluation must be performed, especially in young subjects; family investigation consolidates the diagnosis and enables symptomatic protein C deficient patients to be treated and thrombotic manifestations to be prevented by effective anticoagulant therapy in high-risk situations; a prolonged period of heparin-oral anticoagulant overlap is needed to avoid cutaneous necrosis.
Jonot
F
F
Service de Pneumologie et Allergologie, CHU Rangueil, Toulouse.
Pouchelon
E
E
Cambus
J P
JP
Bierme
R
R
Leophonte
P
P
D000328:Adult; D000925:Anticoagulants / Q000627:therapeutic use; D001780:Blood Coagulation Tests; D006801:Humans; D008297:Male; D010375:Pedigree; D011486:Protein C / Q000032:analysis; D020151:Protein C Deficiency; D013923:Thromboembolism / Q000188:drug therapy / Q000209:etiology* / Q000235:genetics; D014812:Vitamin K / Q000037:antagonists & inhibitors
D000925:Anticoagulants; D011486:Protein C; D014812:Vitamin K
Maladie thrombo-embolique récidivante révélant un déficit en protéine C. A propos d'une observation avec enquête familiale.