NEWS

Liver stiffness by transient elastography to detect porto-sinusoidal vascular liver disease with portal hypertension

Porto-sinusoidal vascular disease (PSVD) refers to a group of rare vascular liver entities causing portal hypertension. PSVD is a much rarer cause of portal hypertension than cirrhosis, which explains, at least in part, why PSVD is still often overlooked and misdiagnosed as cirrhosis.
In this retrospective multicenter study, we assessed the accuracy of liver stiffness measurement (TE-LSM) using transient elastography (Fibroscan™), for discriminating PSVD from cirrhosis in patients with signs of portal hypertension.
We compared TE-LSM in 77 patients with PSVD, to patients with compensated biopsy-proven cirrhosis related to alcohol (n=117), hepatitis C virus (HCV) infection (n=110) or non-alcoholic fatty liver disease (NAFLD) (n=46).
We showed that when compared to cirrhosis, a cut-off value of TE-LSM of 10 kPa had a specificity of 97% for the diagnosis of PSVD, with a 85% positive predictive value. A cut-off value of 20 kPa had a sensitivity of 94% for ruling-out PSVD, with a 97% negative predictive value. Even better results were obtained in a validation cohort including 78 PSVD patients.

February 2020

Erythrocyte-derived microvesicles induce arterial spasms in JAK2V617F myeloproliferative neoplasm

Johanne Poisson, Marion Tanguy, …, Chantal M. Boulanger, Pierre-Emmanuel Rautou
J Clin Invest. 2020. https://doi.org/10.1172/JCI124566

Arterial cardiovascular events are the leading cause of death in patients with JAK2V617F myeloproliferative neoplasms. However, their mechanisms are poorly understood.
In the present study, we observed that genetically modified mice developing JAK2V617F myeloproliferative neoplasms have a strong arterial contraction in response to vasoconstrictors that could account for arterial cardiovascular events observed in patients. We then investigated the mechanisms involved and demonstrated that microvesicles, i.e. cell debris, derived from red blood cells, and circulating in the blood of patients with JAK2V617F myeloproliferative neoplasms transfer a protein (myeloperoxidase) to endothelial cells thus increasing arterial response. We finally showed that treatments, including hydroxyurea and simvastatin, improved arterial response and could thus be attractive to prevent arterial cardiovascular events in patients with JAK2V617F myeloproliferative neoplasms.

November 2019

A defect in endothelial autophagy occurs in patients with alcoholic steatohepatitis and promotes inflammation and fibrosis

 Hammoutene A, Biquard L, Lasselin J, Kheloufi M, Tanguy M, Vion AC, Mérian J, Colnot N, Loyer X, Tedgui A, Codogno P, Lotersztajn S, Paradis V, Boulanger CM, Rautou PE.
J Hepatol. 2019 Nov.

Nonalcoholic fatty liver disease (NAFLD) is the liver manifestation of the metabolic syndrome. NAFLDencompasses a spectrum of histological lesions ranging from simple steatosis to nonalcoholic steatohepatitis (NASH) which includes, in addition to steatosis, hepatocellular injury, inflammation, and varying degree of fibrosis, and can progress to cirrhosis and liver cancer. We recently demonstrated that autophagy is defective in liver endothelial cells of patients with NASH and that this defect is induced by inflammatory mediators present in the portal blood of patients with metabolic syndrome
We also demonstrated that deficiency in autophagy induces liver endothelial cell alterations responsible for liver inflammation, liver cell death and liver fibrosis, thus promoting NASH development .