Arterial thrombosis as clinical manifestation of congenital protein C deficiency

A Case of Ischemic Stroke With Congenital Protein C Deficiency and Carotid Web Successfully Treated by Anticoagulant and Carotid Stenting

Objective: A rare case of thromboembolic cerebral infarction due to carotid web in a patient with congenital protein C deficiency is reported. Case Presentation: A patient in her 40's with left-side hemiparesis was transferred to our hospital under continuous intravenous injection of heparin. Magnetic resonance angiography demonstrated occlusion of the right middle cerebral artery (MCA). Conventional angiography revealed recanalization of the right MCA and a carotid web at the origin of the right internal carotid artery. Ultrasound scan of the carotid artery on the 19th day revealed thrombus formation on the distal portion of the carotid web. We performed carotid artery stenting to prevent thrombus formation by suppressing the carotid web to the vessel wall and by regulating the turbulent flow. The patient had no recurrence of stroke under-anticoagulation with warfarin during the 2-year follow-up period. Conclusion: To our knowledge, this is the first report in which an immediate thrombus formation on the carotid web was observed in a patient with congenital protein C deficiency. In a case of acute ischemic stroke with carotid web, especially when congenital coagulopathy such as protein C deficiency is suspected, careful follow-up with ultrasound imaging should be performed.

Cerebral Infarction Followed by Myocardial Infarction in a Young Adult with Protein C and S Deficiency

Protein C (PC) and protein S (PS) are natural anticoagulants that protect the body against thrombosis, and their deficiency, either inherited or acquired, renders the body to a hypercoagulable state. This leads to venous thromboembolism manifesting as thrombosis, pulmonary embolism and superficial thrombophlebitis among other causes. The involvement of arteries is rare and has been explained by only a few studies. Hence, the presentation of PC and PS deficiencies with stroke and myocardial infarction (MI) is rarely observed, especially in young patients.

We report a case of a 33-year old male with a past medical history of stroke and MI for which no underlying cause was found. He presented now with shortness of breath and left-sided chest pain and after a series of workup, eventually diagnosed as a rare case of PC and PS deficiencies.

Aortic Mural Thrombus Associated with Congenital Protein C Deficiency in an Elderly Patient

Thrombophilia increases the risk of venous thrombosis, but is rarely responsible for aortic thrombosis. Aortic mural thrombus (AMT) may be associated with a protein C deficiency. However, it is necessary to determine whether the protein C deficiency is congenital/hereditary or secondary/acquired (consumption of protein C during the process of thrombus formation). This study describes a 77-year-old Japanese woman with incidentally diagnosed AMT, who had a protein C deficiency (activity 54%, antigen 42%). Sequencing of the protein C gene revealed a heterozygous mutation of c.1268delG, p.Gly423Valfs*82 in exon 9, indicating a congenital protein C deficiency. These findings indicate that very late onset AMT can occur in an adult with congenital protein C deficiency.

Acute Myocardial Infarction as an Initial Presentation of Protein C and Protein S Deficiency Followed by Dilated Cardiomyopathy in a Young Male

Protein C and protein S are vitamin K dependent anti-coagulant proteins required for the inhibition of activated protein V and VIII. In an inherited thrombophilia, hypercoagulability caused by the deficiency of protein C and protein S predisposes an individual to increased risk of thromboembolism (TE) that could herald as a venous thromboemboilsm (VTE) in the leg, pulmonary embolism (PE), stroke, or Budd-Chiari syndrome. However, very rarely does inherited thrombophilia cause coronary artery thrombosis leading to the development of myocardial infarction (MI). We report a case of a young male with combined protein C and protein S deficiency who presented with acute MI, worsened ventricular systolic function, and progressive declination of ejection fraction (EF) secondary to dilated cardiomyopathy (DCM).

Keeping an Open Mind about Acute Flank Pain in Emergency Department: Acute Kidney Infarction

Differential diagnosis of the acute flank pain in a patient without nephrolithiasis is challenging in emergency department. Renal infarction should be suspected if accompanying cardiac arrhythmia, heart failure or valvular disease is present. Activated protein C resistance is the most common thrombophilia that triggers venous-obstructive conditions and rarely arterial thromboembolism. We described a young male with a history of non-ischemic dilated cardiomyopathy and coexisting activated protein C resistance presented with new onset acute flank pain due to acute renal infarction.

Omental gangrene and porto-mesenteric thrombosis in a patient of protein C and protein s deficiency

Omental gangrene is an infrequent cause of acute abdomen with unclear etiology. Hypercoagualable states like protein C or protein S deficiency have never been implicated in the etiology of omental gangrene. We present this case report of a patient having protein C and protein S deficiency presenting with omental gangrene and extensive porto mesenteric thrombosis.

Paroxysmal nocturnal hemoglobinuria: a red clot syndrome

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired, nonmalignant disorder of hematopoietic stem cells characterized by hemolysis, diminished hematopoiesis, and thrombophilia. We describe a 65-year-old woman with known PNH and peripheral arterial disease who presented with critical limb ischemia and a nonhealing left foot ulcer. She underwent surgical bypass of a diffusely diseased left superficial femoral artery with autologous reversed saphenous vein graft. Her postoperative course was complicated by wound sepsis and PNH exacerbation with resultant graft thrombosis requiring an above-knee amputation. This case highlights several key concepts relevant to the management of vascular surgery patients with PNH: (1) their predisposition for arterial and venous thrombosis; (2) hypercoagulability despite standard anticoagulation regimens; (3) the role of eculizumab (a monoclonal antibody that inhibits complement activation used to treat PNH) in reducing thrombotic complications and hemolysis; and (4) complications associated with the immunosuppressive effects of eculizumab. We recommend careful monitoring of hemolysis and immunosuppression, aggressive anticoagulation, frequent graft surveillance, and early consultation with hematology.

A case of a patient with protein C deficiency presenting with concurrent thromboses in the pulmonary arteries and innominate artery: a suggestive computed tomographic finding of thrombophilia

The incidence of arterial thrombosis in patients with protein C deficiency is relatively low compared with that of venous thrombosis. To our knowledge, there is no previously published report of a protein C deficiency patient with simultaneous thromboses in the pulmonary artery and innominate artery in the English literature. We present a case of a protein C deficiency in which the presence of concurrent clots in the pulmonary arteries and innominate artery demonstrated on a pulmonary computed tomographic angiography provided an important clue permitting diagnosis of the deficiency.

Multiple episodes of arterial thrombosis in a young man with protein C deficiency: a case report

A 23-year-old young adult, who had no previous illness, suffered from anterior wall acute myocardial infarction, right renal infarction and occlusion of the left distal brachial artery, popliteal artery, and tibioperoneal trunk artery within six months. He had a habit of smoking but denied a history of drug abuse. Protein C deficiency was diagnosed via the examination of a hypercoagulable panel. The investigation of the hypercoagulable state is essential in young adults with an unusual presentation of artery occlusion.

Coronary thrombosis and myocardial infarction as the initial manifestation of protein C deficiency in a 20-year-old man

We report on a 20-year-old man who presented with an extensive acute anteroseptal myocardial infarction (from a thrombotic occlusion of the left anterior coronary artery) as the initial manifestation of hereditary protein C deficiency. This case report, along with previous reports, indicates that a diagnosis of protein C deficiency in young patients with myocardial infarctions is essential for more appropriate management and for the prevention of recurrent events. Furthermore, family screening could lead to a prophylactic approach in carriers of this mutation.

Protein C and/or S deficiency presenting as peripheral arterial insufficiency

Although protein C and/or S deficiency has frequently been associated with venous thromboembolic events, instances of arterial thromboses have been reported. However, the exact incidence of protein C and/or S deficiency in patients with peripheral arterial insufficiency has not been established. Furthermore, given the lack of adequate studies to define the natural history and angiographic findings of these patients, the treatment has not been well delineated. Therefore, we conducted a prospective study to investigate the prevalence, characteristic angiographic findings and optimal treatments in patients with peripheral arterial insufficiency associated with protein C and/or S deficiency. Between September 2000 and August 2004, 133 patients who presented with peripheral arterial insufficiency underwent hypercoagulability tests before the initiation of any treatments. Of these, 11 patients (8.3%) with protein C and/or S deficiency were included in this study. There were nine males and two females. The ages ranged from 38 years to 72 years (mean 57 years). All patients showed characteristic angiographic findings: long segment thrombotic occlusion of a main peripheral artery without evidence of atherosclerosis or with mild atherosclerotic changes in the aorta and other major arterial trees. Surgical or endovascular procedures were performed in nine patients: bypass graft in four, thrombectomy in four and catheter-directed thrombolysis in one. Conservative treatment with full anticoagulation was performed in two patients. All patients received pre- and post-operative anticoagulation. Except for one amputated case, clinical and vascular laboratory improvements were achieved in 10 patients. Mean follow-up period was 21 months (range 4-45 months). However, one patient, in whom re-vascularization surgery was performed successfully, discontinued warfarin therapy himself at 10 months after surgery, graft occlusion and limb loss occurred at 30 months after surgery. This initial experience suggests that protein C and/or S deficiency may be an independent risk factor for peripheral arterial insufficiency. Patients who present with peripheral arterial insufficiency and protein C and/or S deficiency demonstrate characteristic angiographic findings. Once the diagnosis of protein C and/or S deficiency is made, patients should be treated with life-long anticoagulation.

Syndrome of protein C deficiency and anterior wall acute myocardial infarction at a young age from a single coronary occlusion with otherwise normal coronary arteries

Findings in a 19-year-old man with anterior wall acute myocardial infarction and total occlusion of the left anterior descending coronary artery associated with protein C deficiency are described. In addition, 5 previously reported patients with similar findings are summarized.

[Diagnosis of aortic arch thrombosis by two-dimensional echocardiography from the jugular fossa in a patient with protein C deficiency]

We describe the case of a 63-year-old man who suffered concomitant cerebral, mesenteric, and renal infarctions. Idiopathic dilated myocardiopathy without intracardiac masses was diagnosed by transthoracic echocardiography. A cross-sectional view of the innominate artery from the jugular fossa notch position revealed a threatening thrombus in the proximal region of the aortic arch. Severe functional protein C deficiency was diagnosed by hematologic study.

Multiple aortic thrombi associated with protein C and S deficiency

We describe a woman with an unusual case of thromboembolism of the mesenteric artery in whom multiple thrombi were subsequently found in the aorta and right heart chambers on transesophageal echocardiography. Further evaluation revealed a deficiency of protein C and S plasma proteins, inhibitors of the clotting system. The patient was treated successfully with systemic anticoagulation. Aortic thrombus is common in the setting of underlying atherosclerosis. However, the association of aortic thrombus with a deficiency of protein C and S is rare. To our knowledge, this is the first reported case of mural thrombus of the thoracic aorta associated with combined protein C and S deficiency. Our report underscores the important role of transesophageal echocardiography in the evaluation of patients with arterial thromboembolism.

The endothelial cell protein C receptor (EPCR) functions as a primary receptor for protein C activation on endothelial cells in arteries, veins, and capillaries

Plasma protein C functions as an anticoagulant when it is converted to the active form of serine protease. Protein C activation has been found to be mediated by the endothelial cell surface thrombin/thrombomodulin (TM) complex. In addition, we recently identified the endothelial cell protein C/activated protein C receptor (EPCR) which is capable of high-affinity binding for protein C. In this study, we established monoclonal antibodies (mAbs) against EPCR including several function blocking antibodies. Immunohistochemical analysis using these mAbs demonstrated that EPCR is widely expressed in the endothelial cells of arteries, veins, and capillaries in the lung, heart, and skin. Function blocking anti-EPCR mAbs strongly inhibited protein C activation mediated by primary cultured arterial endothelial cells which express abundant EPCR. Anti-EPCR mAbs also prevent protein C activation mediated by microvascular endothelial cells. These results indicate that EPCR functions as an important regulator for the protein C pathway in various types of vessels.

Analysis of 45 episodes of arterial occlusive disease in Japanese patients with congenital protein C deficiency

Hereditary protein C deficiency is associated with a predisposition to venous thrombosis. It is not clear whether the deficiency is involved in arterial occlusion. In the present study, we screened for protein C amidolytic activity in patients admitted to the National Cardiovascular Center Hospital, and we identified among them 43 probands and 51 relatives with heterozygous protein C deficiency. Among them, 34 patients with heterozygous protein C deficiency had manifested 45 episodes of arterial occlusive disease. Venous thrombotic diseases were less common. In the examination of whether protein C deficiency hastens arterial occlusion, we found a significant difference (p =0.02) in the age at onset of acute myocardial infarction between the patients with protein C deficiency (n=10; 49.4+/-14.8 years) and a group of patients with normal protein C levels (n=42; 60.5+/-10.6 years). Acute myocardial infarction occurred before 40 years of age in a significantly greater proportion of the patients with protein C deficiency (3:10, 30%) as compared with the controls (2:42, 5%) (chi2=5.9, p=0.015). At the onset of atherothrombotic cerebral infarction the patients with protein C deficiency were significantly (p=0.022) younger (n= 11; 57.4+/-12.8 years) than those with normal protein C levels (n=48; 64.6+/-10.1 years). Venous thrombosis was the most frequent clinical manifestation (21 of 31 episodes) in the patients with antithrombin III deficiency (n=26; 68% of the total), who were admitted to our hospital. Thus, our study suggests that congenital protein C deficiency contributes to earlier onset of arterial occlusive diseases, especially acute myocardial infarction, in Japanese subjects.

Activation mechanism of anticoagulant protein C in large blood vessels involving the endothelial cell protein C receptor

Protein C is an important regulatory mechanism of blood coagulation. Protein C functions as an anticoagulant when converted to the active serine protease form on the endothelial cell surface. Thrombomodulin (TM), an endothelial cell surface receptor specific for thrombin, has been identified as an essential component for protein C activation. Although protein C can be activated directly by the thrombin-TM complex, the conversion is known as a relatively low-affinity reaction. Therefore, protein C activation has been believed to occur only in microcirculation. On the other hand, we have identified and cloned a novel endothelial cell surface receptor (EPCR) that is capable of high-affinity binding of protein C and activated protein C. In this study, we demonstrate the constitutive, endothelial cell-specific expression of EPCR in vivo. Abundant expression was particularly detected in the aorta and large arteries. In vitro cultured, arterial endothelial cells were also found to express abundant EPCR and were capable of promoting significant levels of protein C activation. EPCR was found to greatly accelerate protein C activation by examining functional activity in transfected cell lines expressing EPCR and/or TM. EPCR decreased the dissociation constant and increased the maximum velocity for protein C activation mediated by the thrombin-TM complex. By these mechanisms, EPCR appears to enable significant levels of protein C activation in large vessels. These results suggest that the protein C anticoagulation pathway is important for the regulation of blood coagulation not only in microvessels but also in large vessels.

Activated protein C resistance: prevalence and implications in peripheral vascular disease

PURPOSE

Activated protein C (APC) is a naturally occurring anticoagulant that interacts with factors V and VIII to inhibit the clotting cascade. Resistance to APC (APC-R), hypothesized to occur as a result of an abnormal factor V, has been documented in up to 40% of patients with venous thrombotic events, but its prevalence in patients with arterial disease remains ill defined.

METHODS

With an assay of APC resistance that expresses the ratio of the activated partial thromboplastin time with and without the addition of exogenous APC, APC resistance ratios were quantitated in 200 individuals comprising 177 patients with vascular disease and 23 control subjects. An abnormal activated partial thromboplastin time was present in four patients who were excluded from analysis. The 173 remaining patients formed the study population and were divided into diagnostic subgroups on the basis of the most symptomatic problem.

RESULTS

APC resistance was documented in 20 individuals, representing 11.6% of the study group. The highest prevalence of APC resistance was observed in patients with lower extremity occlusive disease, with the APC-R ratio below 2.0 in 13.7%. Within the subgroup of individuals with lower extremity disease, 76 patients (10 with APC-R, 13.2%) underwent infrainguinal bypass and were monitored a mean of 47 +/- 8 months. Occlusion of the arterial reconstruction occurred in 22 patients (29%). Six (60%) of the patients with APC-R had failed reconstructions, versus 16 (24%) of 66 patients without APC-R (p = 0.02).

CONCLUSIONS

These findings suggest that APC-R is relatively common in patients with peripheral vascular disease, especially in those with lower extremity occlusive disease. APC-R appears to be a risk factor for failure of infrainguinal bypass. These observations suggest that screening for APC-R may be useful in patients with peripheral vascular disease, providing the opportunity to restore the normal thrombogenic balance with anticoagulant therapy in susceptible individuals.

Protein C deficiency and stroke in early life

Plasma concentrations of protein C, protein S and antithrombin III were measured in 33 unselected children with a history of cryptogenic stroke (group 1), four children with previously ascertained low plasma concentrations of protein C following stroke (group 2) and 42 healthy children undergoing minor surgery (group 3). Protein S and antithrombin III were normal in all patients. Low concentrations of protein C were found in two patients in group 1 and in six healthy children in group 3. Low protein C concentrations returned to normal over many months in three of the four patients in group 2. Prophylactic antithrombotic therapy and/or termination of pregnancy had been carried out unneccessarily in two families in whom inherited protein C deficiency was not confirmed. The suggestion that heterozygous protein C deficiency contributes to the risk of arterial stroke was not supported by this study.

Cerebral infarction in a young adult associated with protein C deficiency. A case report

Protein C deficiency is a cause of thromboembolic disease. Venous thrombosis is the most common clinical manifestation. Arterial thrombosis is unusual and involvement of the intracranial arteries is especially rare. Herein the authors describe a case of cerebral [correction of cerebellar] infarction associated with protein C deficiency and review the relevant medical literature. A thirty-year-old man was hospitalized because of dysarthria, right limb ataxia, and a gait disturbance. Cranial computed tomography disclosed an infarction in the right cerebellar hemisphere and brachium pontis. Three months earlier the patient had had a transient ischemic attack with truncal ataxia and gait disturbances. On admission, the protein C antigen was 57% and protein C activity was 45%. Investigation of family members revealed protein C deficiency in an uncle. Literature review of stroke cases associated with protein C deficiency revealed that most had had a previous vascular event and/or a positive family history or had used oral contraceptives chronically. Protein C deficiency should be considered in young stroke patients with a positive family history of vaso-occlusive disease, previous ischemic events, or chronic oral contraceptive use.

Accelerated brain infarction in hypertension complicated by hereditary heterozygous protein C deficiency

BACKGROUND

Protein C deficiency leads to reduced inhibition of coagulation and an increased likelihood of thrombosis. It is widely accepted that the most common syndromes associated with protein C deficiency are venous thrombosis and pulmonary thromboembolism, whereas arterial thrombosis is rare. Here we describe two patients with hypertension and hereditary heterozygous protein C deficiency who developed multiple lacunar infarcts.

CASE DESCRIPTIONS

Patient 1 was a 46-year-old man with a history of hypertension who developed a right upper quadrantanopia and gradually progressive intellectual and behavioral deterioration. Patient 2 was a 61-year-old man with history of hypertension and two episodes of right-sided motor weakness who developed left sixth and seventh cranial-nerve palsies and reduced pinprick sensation in the right extremities. In both patients, magnetic resonance imaging revealed multiple small lesions in the pons as well as the bilateral basal ganglia, thalamus, corona radiata, and other subcortical structures, which are consistent with lacunar infarcts. Protein C activity and antigen levels were reduced to approximately one half of normal in these two patients, as well as in some of their family members who had no other serological or coagulation abnormalities. A diagnosis of heterozygous protein C deficiency type 1 was thus established.

CONCLUSIONS

Although it remains uncertain whether protein C deficiency itself increases the risk of cerebral artery thrombosis, it may predispose a patient to develop multiple brain infarctions in association with hypertension.

Congenital protein C deficiency and myocardial infarction:concomitant factor VII hyperactivity may play a role in the onset of arterial thrombosis

A 29-year-old man with congenital protein C deficiency and acute myocardial infarction is reported. Four hours after the onset of chest pain, he was treated intravenously with tissue-type plasminogen activator. Subsequent coronary angiography revealed only slight stenosis of the left anterior descending coronary artery without any atherosclerosis. The propositus, his brother, and his mother, showed low levels of both protein C activity and antigen, while plasma thrombomodulin levels were normal. His grandfather had died from acute myocardial infarction at 38 years of age. We investigated several other risk factors for arterial thrombosis, including factor VII, fibrinogen, heparin cofactor II, lipoprotein (a), and anticardiolipin antibodies. No other haemostatic abnormalities apart from factor VII hyperactivity were detected in this family. To study the effects of protein C and factor VII on procoagulant activity, prothrombin time was measured after the addition of activated protein C and factor VII to protein C-deficient plasma. The prothrombin time ratio decreased along with an increase in the factor VII level. It also decreased with a decrease in the activated protein C level. These findings indicated that the procoagulant activity of factor VII was enhanced by low protein C levels, suggesting that concomitant factor VII hyperactivity may cause acute myocardial infarction in patients with protein C deficiency.