K. VanHoorelbeke PhD

Gene therapy for von Willebrand Disease

SUMMARY

von Willebrand disease (VWD) is the most common inherited bleeding disorder, caused by mutations in the von Willebrand factor (VWF) gene. These mutations can affect the biosynthesis, secretion, function or clearance of VWF. As a result, quantitative or qualitative abnormalities of VWF lead to the bleeding phenotype found in VWD patients. Current management of VWD aims at correcting the bleeding phenotype via the use of supportive therapy, stimulating the release of endogenous VWF reserves and implementation of replacement strategies. Despite current treatment options, VWD patients experience a substantial negative impact on their overall health-related quality-of-life (HRQoL). Development of long-term approaches to manage VWD would not only avoid the current limitations of short-term therapies but could also significantly ameliorate the HRQoL of VWD patients. Gene therapy for VWD offers the potential of a long-term, if not lifelong, correction of VWF deficiency. During the last two decades, gene therapy for VWD has been studied via different strategies. The aim of this review is to give an overview of the different strategies and improvements that were investigated to develop a gene therapy for VWD.

(BELG J HEMATOL 2023;14(8):326–30)

Diagnosis and treatment of thrombotic thrombocytopenic purpura

SUMMARY

Thrombotic thrombocytopenic purpura (TTP) is a rare and life-threatening thrombotic microangiopathic disorder (TMA) due to a severe deficiency of ADAMTS13 (A Disintegrin And Metalloprotease with Thrombo-Spondin type 1 repeats, member 13). The deficiency in ADAMTS13 can either be caused by mutations in ADAMTS13 (congenital TTP or Upshaw-Schulman syndrome, cTTP) or by anti-ADAMTS13 autoantibodies (immune-mediated TTP, iTTP). Diagnosis of TTP is challenging but crucial for the survival of the patient. TTP should be suspected when microangiopathic haemolytic anaemia and severe thrombocytopenia are observed. A severely decreased ADAMTS13 activity (activity <10%) should confirm the diagnosis of TTP. Standard treatment of TTP is plasma therapy (plasma exchange for iTTP, while plasma infusion for cTTP), but novel therapeutics like rituximab, caplacizumab and recombinant ADAMTS13 show promising results regarding the recovery and sustained remission of TTP patients. However, although major advances have been made in the management of TTP, TTP is a chronic disease and patients still relapse, careful and stringent patient follow-up is needed to improve the patients’ quality of life.

(BELG J HEMATOL 2020;11(6):253-60)

P30 VWF DEFICIENCY IS ASSOCIATED WITH RETICULOCYTOSIS AND INCREASED PARASITE ACCUMULATION IN EXPERIMENTAL MALARIA-ASSOCIATED ACUTE RESPIRATORY DISTRESS SYNDROME

P28 THE MECHANISM OF THE LOSS OF HMW VWF MULTIMERS AFTER LEFT VENTRICULAR ASSIST DEVICE IMPLANTATION IS DIFFERENT BETWEEN HUMANS AND SHEEP

P27 VON WILLEBRAND FACTOR DEFICIENCY DOES NOT INFLUENCE ANGIOTENSIN I I-INDUCED ABDOMINAL AORTIC ANEURYSM FORMATION IN MICE

P22 ANTI-CUB1 OR ANTI-SPACER ANTIBODIES THAT INCREASE ADAMTS13 ACTIVITY ACT BY ALLOSTERICALLY ENHANCING METALLOPROTEASE DOMAIN FUNCTION

P21 A NOVEL ADAMTS13 CONFORMATION ELISA SHOWS CONFORMATIONAL ACTIVATION OF RAT ADAMTS13 WITH EXPOSURE OF CRYPTIC EPITOPES IN VITRO