Objective To compare in vitro and in vivo biological and biochemical properties of five liquid intravenous immunoglobulin (IVIg) preparations licensed for therapeutic use in Europe. Methods ClairYg ® was compared in a blinded manner to four other liquid IVIg preparations licensed in Europe (Octagam ® , Kiovig ® , Gamunex ® , Privigen ® ). Three batches of each preparation were tested, except for the IgG repertoires and the animal model. Results Levels of anti‐A and anti‐B antibodies were lower in ClairYg ® (0·11/0·11) relative to a positive EDQM standard and Octagam ® (0·11/0·08) than in other preparations (0·33–0·69/0·42–0·46). IgG in ClairYg ® recognized 365 and 416 protein spots in HEp‐2 cell and Escherichia coli protein extracts vs. 230–330 and 402–842 protein spots, respectively, for IgG in other preparations. IgA content (301 vs. 165–820 ng/mg of IgG), Factor XI and Factor XII antigen (0·46 vs. 0·85–2·40 mU/mg of IgG and 7·8 vs. 20·0–46·2 lU/mg of IgG) C1q binding (0·42 vs. 0·67–1·89 arbitrary units) and C5a uptake (0·41 vs. 0·45–0·66% of activation) were lower in ClairYg ® than in other preparations. Finally, intravenous infusion of ClairYg ® , Gamunex ® and Privigen ® had no major effect on arterial blood pressure in spontaneously hypertensive rats. Conclusions Our results evidence some differences in the biological and biochemical properties among licensed liquid IVIg preparations.

Background Since the early 1990s 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.

Factor XI (FXI) deficiency is an inherited autosomal recessive disorder associated with bleeding of variable severity. However, many cases of dominant disease transmission have been recently described. This disorder is rare in the general population, whereas it is commonly found in individuals of Ashkenazi Jewish ancestry. This study reports the molecular genetic analysis of FXI deficiencies in 11 unrelated families of different origin. Five novel mutations have been identified. Severe FXI deficiency of two unrelated patients resulted from two novel mutations: one deletion (960-961delGT) in exon 9 predicting a frameshift, and a Ser-4Leu mutation located in the signal peptide. In addition, three novel missense mutations associated with partial FXI deficiency have been identified: Cys122Tyr, Glu297Lys and Glu579Lys.

Replacement therapy is the treatment of choice for patients with von Willebrand disease who are unresponsive to desmopressin. In order to prevent transmission of non-enveloped viruses, a solvent/detergent-treated plasma-derived von Willebrand factor available in France since 1989 has been subjected to additional removal/inactivation steps by 35 nm filtration and dry heating for 72 h at 80 degrees C. This preclinical study evaluates the potential immunogenicity of this new product by comparing the antibodies raised in pigs affected with von Willebrand disease after intravenous injection of either a solvent/detergent-treated product or a triple-secured product. Our data showed that there is no difference between the two products in terms of the rate and intensity of the humoral response measured by both binding and neutralizing antibody levels. It was concluded that no antigenic alterations of von Willebrand factor molecules during the nanofiltration and final dry-heating steps were detected in our animal model. (c) 2005 Lippincott Williams & Wilkins.

desmopressin kg bw given intravenously in 164 patients (97 females, 67 males; age 6±77 years) suffering from vWD (n = 108) including mainly type 1 (n = 96), haemophilia A (n = 21), platelet dysfunction (n = 13) and low platelet counts (n = 22). FVIII and vWF were measured by coagulation or immunological assays, respectively, before and 30 min after drug administration. The antihaemorrhagic effect in those patients (n=65) who had acute haemorrhages or were submitted to invasive measurements, respectively, was evaluated by detecting the cessation or prevention of bleedings. The increase (mean ‹ SD) of FVIII (coagulatory acitivty) and vWF (concentration) was 4.36fold ‹ 2.54 and 2.68-fold ‹ 1.08 in vWD; 3.89-fold ‹ 1.87 and 2.00-fold ‹ 0.79 in haemophilia; 1.67-fold ‹ 0.52 and 1.88-fold ‹ 0.62 in platelet dysfunctions; and 2.08fold ‹ 0.55 and 1.94-fold ‹ 0.63 in low platelet counts. Compared to baseline levels, increase of FVIII/VWF was signi®cant (P < 0.05) in vWD and haemophilia but not strictly in platelet disorders. Increase of FVIII was significantly higher in vWD and haemophilia compared to platelet disorders. FVIII elevation was signi®cantly higher than VWF increase except for platelet dysfunctions. The increase of VWF was highest in vWD, however, it did not differ signi®cantly from the other disorders. Maximum levels of FVIII, except for haemophilia, and of VWF following desmopressin were not signi®cantly different among the disorders investigated. The antihaemorrhagic effect was 93.5% in vWD, 80% in haemophilia, 83.3% in platelet dysfunction and 72.2% in low platelet counts. We conclude from these data that FVIII and VWF response on desmopressin is variable depending on the underlying disease and that VWF de®ciency in vWD is rather a distributional disorder than a quantitative defect, since highest VWF levels consecutively to desmopressin were not different in vWD compared to the disorders without VWF abnormality. High antihaemorrhagic response, as demonstrated too for platelet disorders, suggests that possibly additional mechanisms aside from FVIII/VWF increase arise from desmopressin administration.

En accord avec les recommandations europeennes, le LFB a etudie la possibilite d'introduire des etapes supplementaires d'inactivation et/ou d'elimination virale, dirigees principalement contre les virus non enveloppes, dans le processus de fabrication de son concentre therapeutique de facteur Willebrand (vWF). Le produit issu de la phase de developpement preclinique a pour nom de code « vWF SD-35-DH » car il subit, en plus des etapes habituelles de preparation du FACTEUR WILLEBRAND-LFB®, une filtration a 35 nm et un chauffage a sec (dry heating). Les conditions de la filtration a 35 nm ont ete fixees afin d'assurer le passage des multimeres du vWF superieurs au pentadecamere. Le chauffage a sec a 80 °C pendant 72 heures a necessite une etude prealable pour etablir la formulation optimale permettant de conserver les specifications generales du produit (aspect et solubilite de la poudre) ainsi que ses caracteristiques structurales (composition multimerique) et fonctionnelles (fixation a la GPlb plaquettaire, au facteur VIII et au collagene) de son principe actif. Les caracteristiques des 6 lots industriels prepares en 1998 ainsi que l'etat d'avancement du developpement du vWFSD-35-DH sont presentes.

SCID mice were grafted with human PBL (hu-PBL-SCID) from healthy or haemophilia A donors. Those containing human and no murine Ig in their plasma, were injected with 100 U VIII:Ag of a plasma derived (pd) FVIII or recombinant deleted Factor VIII (FVIII deltaII) and with 10 microg of tetanus toxoid as control immunogen. The frequency and the intensity of the humoral specific responses were measured in 253 mice humanized with PBL from 13 different donors. There was no significant difference in the frequency or intensity of the anti-FVIII immune responses to pd FVIII and FVIII deltaII. Neutralizing antibodies were only detected in the plasma of mice humanized with cells from haemophiliacs having FVIII inhibitors in their blood. The immune responses observed in hu-PBL-SCID mice correlated with the immune status of the corresponding human donor.