Ischemic Vascular Events as Clinical Manifestation of Protein C Deficiency

Case Report

Austin J Clin Neurol 2015;2(4): 1039.

Ischemic Vascular Events as Clinical Manifestation of Protein C Deficiency

Honghong Li*, Shuwei Qiu*, Ying Peng

Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China

*H. Li and S. Qiu contributed equally to this work

*Corresponding author: Ying Peng, M.D., Ph.D., Professor, Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University. No. 107 West Yanjiang Road, Guangzhou, China

Received: March 02, 2015; Accepted: March 31, 2015; Published: April 06, 2015


We report three patients who suffered from recurrent vascular ischemic events associated with a protein C deficiency to highlight the importance of evaluating protein C activity in young patients of recurrent vascular events without major risk factors. Protein C deficiency presenting with cerebral ischemic has been only rarely observed. Anticoagulation therapy combined with fresh frozen plasma in the acute phase received good curative effect. These three cases indicate that the determination of protein C levels is valuable in the evaluation of patients with recurrent vascular events. Early diagnosis and treatment can prevent severe consequences.

Keywords: Protein C deficiency; Cerebral infarction; Venous thrombosis; Anticoagulation; Fresh frozen plasma


Protein C (PC) is a vitamin K-dependent plasma glycoprotein that exerts a critical role in the regulation of coagulation [1-3]. PC is produced in hepatocytes and circulates in a very low concentration. It can be activated on the endothelial cells by thrombin binding to the membrane protein thrombomodulin. Once activated, PC acts as an anticoagulant via inactivating the procoagulation factors, factors V (FV) and VIII (FVIII). Protein S, which is also a vitamin K-dependent plasma protein, augments the activity of PC during the anticoagulation.

PC deficiency is inherited as an autosomal dominant disorder with a morbidity of 0.02-0.5% [4], and is identified when the PC concentration or activity is below 60-70% of the overall mean concentration or activity [5]. Patients with mild PC deficiency have an increased risk of venous thrombosis because of the imbalance between procoagulant and anticoagulant pathways. Severe PC deficiency is associated with neonatal purpura fulminans [6]. PC deficiency in the young patients usually manifest as venous thrombotic complications, including superficial thrombophlebitis, deep venous thrombosis, and pulmonary embolism. There have been few reports of PC deficiency presenting with ischemic stroke.

We report three cases who suffered from recurrent vascular ischemic events due to PC deficiency to highlight the importance of evaluating PC activity in young patients and to stress the importance of early diagnosis and timely treatment of this condition to prevent severe complications.

Case Presentation

Patient 1

A man was admitted to our department with a sudden onset of left-sided hemiparesis. There were recurrent epileptic seizures of his left side limbs before admission. In 2006, the patient experienced deep vein thrombosis in his lower limbs. He developed a mesenteric venous thrombosis, and portal venous thrombosis. He had been healthy until when he developed deep vein thrombosis. The patient had neither hypertension nor diabetes, and there were no obvious precipitants of thrombosis. He also denied the habits of smoking or drinking. The family history about vascular events of the patient was unremarkable.

The results of the general physical examination were normal. Neurological examination showed slightly hypoesthesia of the left limbs and trunk. He had Medical Research Council grade 4/5 muscle power over the left limbs. Laboratory tests including routine blood parameters, blood biochemistry, hyperhomocysteinemia, platelet count, platelet aggregation, prothrombin and partial thromboplastin times, factor VIII, antithrombin III activity, and protein S were all within normal limits. Fibrinogen and antithrombin III concentrations were slightly lower than the normal value. Other possible causes of stroke in the young including: serum electrolytes, renal and liver function, erythrocyte sedimentation rate were normal. The patient was negative for syphilis and hepatitis. However, the protein C functional activity of the patient’s plasma was only 23.1% (normal, 70-140%). The cerebrospinal fluid (C.S.F) opening pressure was 190 mmH2O without any other abnormality. Cardiologic investigations including electrocardiography, Holter electrocardiographic monitoring, and two-dimensional echocardiography did not suggest any abnormality. Double carotid chromatic ultrasonic (DCCU) did not show arteriosclerotic lesions in bilateral carotid. Brain magnetic resonance imaging (MRI) showed a prominent subacute cerebral infarction of the right side of the frontal lobes (Figure 1).

Citation: Li H, Shu-Wei Qiu, Xiang-Pen Li, Li Y, He L and Peng Y. Ischemic Vascular Events as Clinical Manifestation of Protein C Deficiency. Austin J Clin Neurol 2015;2(4): 1039. ISSN : 2381-9154