[Deficiencies in proteins C and S in a patient with idiopathic portal hypertension accompanied by portal vein thrombosis]

Molecular Mechanisms Underlying Vascular Liver Diseases: Focus on Thrombosis

Vascular liver disorders (VLDs) comprise a wide spectrum of clinical-pathological entities that primarily affect the hepatic vascular system of both cirrhotic and non-cirrhotic patients. VLDs more frequently involve the portal and the hepatic veins, as well as liver sinusoids, resulting in an imbalance of liver homeostasis with serious consequences, such as the development of portal hypertension and liver fibrosis. Surprisingly, many VLDs are characterized by a prothrombotic phenotype. The molecular mechanisms that cause thrombosis in VLD are only partially explained by the alteration in the Virchow's triad (hypercoagulability, blood stasis, and endothelial damage) and nowadays their pathogenesis is incompletely described and understood. Studies about this topic have been hampered by the low incidence of VLDs in the general population and by the absence of suitable animal models. Recently, the role of coagulation imbalance in liver disease has been postulated as one of the main mechanisms linked to fibrogenesis, so a novel interest in vascular alterations of the liver has been renewed. This review provides a detailed analysis of the current knowledge of molecular mechanisms of VLD. We also focus on the promising role of anticoagulation as a strategy to prevent liver complications and to improve the outcome of these patients.

Porto-sinusoidal vascular disorder

It is well established that portal hypertension can occur in the absence of cirrhosis, as reported in patients with immune disorders, infections and thrombophilia. However, similar histological abnormalities primarily affecting the hepatic sinusoidal and (peri)portal vasculature have also been observed in patients without portal hypertension. Thus, the term porto-sinusoidal vascular disorder (PSVD) has recently been introduced to describe a group of vascular diseases of the liver featuring lesions encompassing the portal venules and sinusoids, irrespective of the presence/absence of portal hypertension. Liver biopsy is fundamental for PSVD diagnosis. Specific histology findings include nodular regenerative hyperplasia, obliterative portal venopathy/portal vein stenosis and incomplete septal fibrosis/cirrhosis. Since other conditions including alcohol-related and non-alcoholic fatty liver disease, or viral hepatitis, or the presence of portal vein thrombosis may occur in patients with PSVD, their relative contribution to liver damage should be carefully assessed. In addition to histology and clinical diagnostic criteria, imaging and non-invasive tests such as liver and spleen stiffness measurements could aid in the diagnostic workup. The introduction of PSVD as a novel clinical entity will facilitate collaborative studies and investigations into the underlying molecular pathomechanisms encompassed by this term.

[Clinical manifestations and gene analysis of 18 cases of hereditary protein S deficiency]

Objective: To analyze the clinical manifestations and molecular pathogenesis of 18 patients with inherited protein S (PS) deficiency. Methods: Eighteen patients with inherited PS deficiency who were admitted to the Institute of Hematology & Blood Diseases Hospital from June 2016 to February 2019 were analyzed: activity of protein C (PC) and antithrombin (AT) , PS activity were measured for phenotype diagnosis; high throughput sequencing (HTS) was used for screening of coagulation disease-related genes; Sanger sequencing was used to confirm candidate variants; Swiss-model was used for three-dimensional structure analysis. Results: The PS:C of 18 patients ranged from 12.5 to 48.2 U/dL. Among them, 16 cases developed deep vein thrombosis, including 2 cases each with mesenteric vein thrombosis and cerebral infarction, and 1 case each with pulmonary embolism and deep vein thrombosis during pregnancy. A total of 16 PROS1 gene mutations were detected, and 5 nonsense mutations (c.134_162del/p.Leu45*, c.847G>T/p.Glu283*, c.995_996delAT/p.Tyr332*, c.1359G> A/p.Trp453*, c.1474C>T/p.Gln492*) , 2 frameshift mutations (c.1460delG/p.Gla487Valfs*9 and c.1747_1750delAATC/p.Asn583Wfs*9) and 1 large fragment deletion (exon9 deletion) were reported for the first time. In addition, the PS:C of the deep vein thrombosis during pregnancy case was 55.2 U/dL carrying PROC gene c.565C>T/p.Arg189Trp mutation. Conclusion: The newly discovered gene mutations enriched the PROS1 gene mutation spectrum which associated with inherited PS deficiency.

Recurrent esophagogastric variceal bleeding due to portal vein thrombosis caused by protein S deficiency

Background and study aims  Esophagogastric variceal bleeding (EGVB) is common in patients with portal vein thrombosis (PVT). Hereditary deficiencies in natural anticoagulant proteins, such as protein S, might contribute to PVT. However, recurrent EGVB caused by PVT in patients with protein S deficiency is seldom reported. Herein, we present the case of a 38-year-old man with protein S deficiency complicated with PVT. The patient suffered recurrent EGVB for 7 years. He underwent splenectomy plus pericardial revascularization and sequential endoscopic therapy, including one gastric variceal obturation (GVO) procedure and two esophageal variceal ligations (EVL) to eradicate the varices. Rivaroxaban was administrated to reduce risk of thrombotic events. The patient is currently well without rebleeding after 1 year of follow-up. To our knowledge there is no consensus on management of recurrent EGVB on the basis of thrombophilia complicated with PVT. According to our practice, sequential endoscopic therapy combined with anticoagulant appears to be effective and safe.

Portal vein thrombosis with protein C-S deficiency in a non-cirrhotic patient

There are several conditions that can lead to portal vein thrombosis (PVT), including including infection, malignancies, and coagulation disorders. Anew condition of interest is protein C and S deficiencies, associated with hypercoagulation and recurrent venous thromboembolism. We report the case of a non-cirrhotic 63-year-old male diagnosed with acute superior mesenteric vein thrombosis and PVT and combined deficiencies in proteins C and S, recanalized by short-term low molecular heparin plus oral warfarin therapy.

A case of portal vein thrombosis by protein C and s deficiency completely recanalized by anticoagulation therapy

Portal vein thrombosis (PVT) is a rare form of venous thrombosis that affects the hepatic portal vein flow, which can lead to portal hypertension. Treatment of PVT includes anticoagulants, thrombolysis, insertion of shunts, bypass surgery, and liver transplantation. Single anticoagulation therapy is not regarded as a curative treatment but can be associated with a reduction in new thrombotic episodes. We experienced a case of acute total occlusion of PVT provoked by protein C and S deficiency syndrome. PVT was completely recanalized with oral anticoagulant therapy following low molecular weight heparin therapy.