A qualitative and quantitative analysis of von Willebrand factor contained in a very high-purity plasma-derived FVIII concentrate.

BACKGROUND AND OBJECTIVES: We studied the structural and functional properties of von Willebrand factor (VWF) molecules present in a very high-purity plasma-derived factor VIII concentrate (VHP pdFVIII - Factane® ) because several observations suggest that the presence of VWF in factor VIII (FVIII) preparations may decrease their immunogenicity. MATERIALS AND METHODS: Ten marketed batches of VHP pdFVIII (Factane® ) with levels of VWF ranging from 15 to 39 IU/100 IU FVIII were analysed. The VWF multimeric pattern was studied by agarose gel electrophoresis. The binding of VWF to FVIII was studied by gel filtration and ELISA. The binding of VWF to GPIb was analysed by ELISA. RESULTS: The results showed that high-molecular-weight multimers of VWF were present in VHP pdFVIII (Factane® ). VWF subunits maintain a triplet structure similar to that of normal plasma. Regardless of the VWF content, all FVIII molecules of each batch were co-eluted with VWF, and no free FVIII was detectable. By immunoassays, VWF was found to be able to bind to FVIII and platelet GPIb in a similar manner to that of VWF in normal plasma. CONCLUSIONS: In all the VHP pdFVIII (Factane® ) batches studied, regardless of the level of VWF, the structure and capacity of VWF binding to FVIII and to platelet GPIb were fully preserved.

Femoral tripod arteries: Surgical anatomic variants.

AIM: To describe the surgical anatomy of the femoral tripod arteries and their anatomical variants. MATERIALS AND METHODS: Patients who underwent vascular surgery by external arciform approach of the Scarpa between May 2022 and July 2022 were selected. The surgical anatomy was assessed by direct observation. The origin and the course of major branches of the femoral artery (FA) were studied. Diameters and the distance of the origin of the femoral profunda artery (FPA) from the midpoint of the inguinal ligament was measured in millimeters and recorded. The observed anatomical variations were photographed and compared to those in the literature. RESULTS: A total of 40 patients (34 men, 85%) were included. The median diameter of the common femoral artery (CFA) was 9mm (IQR: 7-12mm). The Modal bifurcation was noted in 95% of cases. The collateral branches of the CFA were found to be distributed as follows: the superficial circumflex iliac artery (SCIA) in 34 cases (85%), the superficial epigastric artery (SEA) in 22 cases (55%), the deep external pudic artery in 16 cases (40%), and the superficial external pudic artery in 18 cases (45%). The median diameter of the FPA was 5mm (IQR: 4-6mm). The FPA originated from the posterolateral side of the CFA in 90% of cases, from the posterior side in 5% of cases and from the medial side in 5% of cases. The median diameter of the SFA was 6mm (IQR: 4-9mm). CONCLUSION: The anatomic variants of the femoral tripod arteries are extremely frequent. Therefore, it is important to recognize the anatomy in order to avoid possible diagnostic errors and to minimize the risk of per and post procedural complications.

[Diagnosis of an opacity at the lung base: intrathoracic kidney]. / Diagnostic d'une opacité de la base pulmonaire: le rein intra-thoracique.

A 72-year-old patient was admitted for exploration of an opacity of the left base discovered fortuitously on a routine chest x-ray. Initial blood tests were normal. Fiberoptic bronchoscopy was normal. Computed tomography (CT) led to the diagnosis of a left kidney which had risen into a retro-cardiac position. Magnetic resonance imaging established the sub-diaphragmatic position of the kidney. Renal excretion was normal on intravenous urography. An ectopic kidney in an intrathoracic position is very uncommon and may raise a major challenge when visualized as a mediastinal or pulmonary opacity. Computed tomography or intravenous urography can provide the diagnosis and magnetic resonance imaging demonstrates its precise sub-diaphragmatic or supra-diaphragmatic position.

Left ventricular thrombus complicating tachycardia-induced cardiomyopathy.

A 45 day old new-born with arrhythmia-induced cardiomyopathy complicated by thrombus formation is presented. Drug treatment produced immediate symptomatic relief and subsequent reversion to normal cardiac function. The thrombus disappeared a few days later.

A solvent/detergent-treated and 15-nm filtered factor VIII: a new safety standard for plasma-derived coagulation factor concentrates.

BACKGROUND: Since the early 1990 s the Committee for Proprietary Medicinal Products has set the mandatory requirement that all manufacturing processes for blood products include two virus removal/inactivation steps that are complementary in their action. OBJECTIVES: The objective was to develop a manufacturing process for factor VIII (FVIII) including two complementary steps of viral inactivation/elimination. METHODS: A 35-15 nm nanofiltration step was added to a former FVIII manufacturing process that included solvent/detergent (S/D) treatment to generate a new FVIII concentrate called Factane. The impact of nanofiltration on the structural and functional characteristics of FVIII, as well as virus/transmissible spongiform encephalopathy reduction factors were assessed. RESULTS: Using an innovative approach, FVIII was successfully nanofiltered at 35-15 nm, while the biological properties of the active substance were unmodified. FVIII coagulant and antigen content for Factane and previous S/D-treated FVIII (FVIII-LFB, commercialized as Facteur VIII-LFB) were comparable. The FVIII one-stage chromogenic and coagulant/antigen ratios confirmed that nanofiltered FVIII was not activated. After nanofiltration, the copurified von Willebrand factor (vWF) was reduced but vWF/FVIII binding properties were unaffected. Phospholipid binding and thrombin proteolysis studies displayed no differences between Factane and FVIII-LFB. The rate of factor Xa generation was slightly lower for Factane when compared to FVIII-LFB. Viral validation studies with different viruses showed no detectable virus in the filtrate. CONCLUSIONS: Nanofiltration of FVIII at 15 nm is feasible despite the large molecular weight of FVIII and vWF. Nanofiltration has been proven to be highly effective at removing infectious agents while preserving the structural and functional integrity of FVIII.

In vitro study of a triple-secured von Willebrand factor concentrate.

BACKGROUND AND OBJECTIVES: Patients suffering from von Willebrand disease who are not responsive to desmopressin require substitutive treatment. This study was part of the development of a second-generation plasma-derived von Willebrand factor (VWF) concentrate, the manufacturing process of which includes two complementary viral-inactivation/elimination steps that are effective against non-enveloped viruses. MATERIALS AND METHODS: VWF was purified from solvent/detergent-treated cryoprecipitate through a combination of anion-exchange and affinity chromatography. The VWF preparation was diluted and filtered through filters with pore size of 35 nm. After concentration and formulation, the product was freeze-dried and further heated at 80 degrees C for 72 h. Tests were performed to evaluate the effects of nanofiltration and dry heating on VWF multimeric structure and function. RESULTS: Nanofiltration and dry heating of the formulated product increased viral safety but did not modify VWF multimeric structure. Furthermore, these steps did not alter the ability of VWF to bind to platelet glycoprotein Ib, collagen and Factor VIII. CONCLUSIONS: We have perfected a large-scale manufacturing process to produce a human plasma-derived VWF concentrate that boasts high specific activity and is very safe for the treatment of patients with von Willebrand disease.

Purification of human ceruloplasmin as a by-product of C1-inhibitor.

Human ceruloplasmin (Cp) has been purified from cryoprecipitate-poor plasma as a by-product of the C1-inhibitor production chain. Highly purified Cp was obtained by subsequent ion-exchange chromatography on sulfate-Fractogel EMD and TMAE-Fractogel EMD. Treatments for viral safety included application of the solvent-detergent method and two nanofiltration steps using 35- and 15-nm pore size filters at the end of the process. Overall antigen yield was 95 (+/-5) %. Purified human ceruloplasmin was studied by electron spin resonance (ESR) to characterize its different types of copper complexes and to check its antioxidant properties. We distinguished three types of complexes: one type-2 Cu(II) with g// = 2.25 and A// = 180 G and two type-I Cu(II) exhibiting different narrow hyperfine splitting (A// = 72 G and A// = 90 G) with close g// (2.20 and 2.21). Purified Cp has a specific activity of 24.5+/-0.2 mU/mg of proteins. This process provides a method for Cp purification that could be easily integrated into modern plasma fractionation.

[Pseudotumoral abdominal cysto-steato-necrosis: an unusual etiology]. / Cystostéatonécrose abdominale pseudo-tumorale: une étiologie inhabituelle.

We report an unusual case of subcutaneous pseudo-neoplastic focal fat necrosis in a woman with a Mersilen plate placed outside the abdominal wall muscles. To our knowledge, this association has not been previously reported in the radiologic literature. The differential diagnosis using ultrasound and computerized tomography is discussed.