von Willebrand Factor Standards for Plasma and Concentrate Testing

ABSTRACT

The wide range of plasma von Willebrand factor (vWF) levels in the normal population makes vWF an ideal candidate for calibration in World Health Organization International Standards (WHO IS). Calibration of the WHO IS Plasma for vWF:antigen (vWF:Ag), vWF:ristocetin cofactor activity (vWF:RCo), and vWF:collagen-binding activity (vWF:CB) addresses the need to reconcile the original definition of the International Unit (IU) in fresh normal plasma with continuity between replacement freeze-dried preparations, whereas calibration of the WHO IS Concentrate aims to maintain equivalence between the IU used for the estimation of vWF in plasma (diagnosis) and the IU used for the potency labeling of therapeutic concentrates (replacement therapy). The latter objective was achieved through the calibration of the WHO 1st IS vWF Concentrate, for vWF:Ag and vWF:RCo, by assay directly relative to the WHO IS Plasma. Calibration of the WHO IS Concentrate for vWF:CB was not possible due to large interlaboratory and intermethod discrepancies, and resolution of this problem may require the use of recommended methodology. There is evidence that the use of the WHO IS Concentrate leads to considerable reduction in interlaboratory variability for vWF estimates in therapeutic concentrates and hence the “assay like versus like” principle should be applied.

von Willebrand factor (vWF) - International Standard - ristocetin cofactor - collagen binding

REFERENCES

• 1 Gill J C, Endres-Brooks J, Bauer P J, Marks W J, Montgomery R R. The effect of ABO blood group on the diagnosis of von Willebrand disease.  Blood. 1987;  69 1691-1695
• 2 Barrowcliffe T W, Tydeman M A, Kirkwood T BL, Thomas D P. Standardization of factor VIII. III: establishment of a stable reference plasma for factor VIII-related activities.  Thromb Haemost. 1983;  50 690-696
• 3 Hubbard A R, Sands D, Chang A C, Mazurier C. Standardisation of von Willebrand factor in therapeutic concentrates: calibration of the 1st International Standard for von Willebrand Factor Concentrate (00/514).  Thromb Haemost. 2002;  88 380-386
• 4 Kirkwood T BL, Barrowcliffe T W, Thomas D P. An international collaborative study establishing a reference preparation for antithrombin III.  Thromb Haemost. 1980;  43 10-15
• 5 Hubbard A R. Standardisation of protein C in plasma: establishment of an international standard.  Thromb Haemost. 1988;  59 464-467
• 6 Hubbard A R. Standardisation of protein S in plasma: calibration of the 1st International Standard.  Thromb Haemost. 1997;  78 1237-1241
• 7 Heath A B, Barrowcliffe T W. Standardisation of factor VIII-V. Calibration of the 2nd International Standard for factor VIII and von Willebrand factor activities in plasma.  Thromb Haemost. 1992;  68 155-159
• 8 Hubbard A R, Rigsby P, Barrowcliffe T W. Standardisation of factor VIII and von Willebrand factor in plasma: calibration of the 4th International Standard (97/586).  Thromb Haemost. 2001;  85 634-638
• 9 Hubbard A R, Heath A B. Standardization of factor VIII and von Willebrand factor in plasma: calibration of the WHO 5th International Standard (02/15).  J Thromb Haemost. 2004;  2 1380-1384
• 10 Brown J E, Bosak J O. An ELISA test for the binding of von Willebrand antigen to collagen.  Thromb Res. 1986;  43 303-311
• 11 Favaloro E J, Grispo L, Exner T, Koutts J. Development of a simple collagen based ELISA assay aids in the discrimination of, and permits sensitive discrimination between Type I and II von Willebrand's disease.  Blood Coagul Fibrinolysis. 1991;  2 285-291
• 12 Casonato A, Pontara E, Bertomoro A, von Sartorello F. Willebrand factor collagen binding activity in the diagnosis of von Willebrand disease: an alternative to ristocetin co-factor activity?.  Br J Haematol. 2001;  112 578-583
• 13 Favaloro E J. von Willebrand factor collagen-binding (activity) assay in the diagnosis of von Willebrand disease: a 15-year journey.  Semin Thromb Hemost. 2002;  28 191-202
• 14 Favaloro E J. Collagen binding assay for von Willebrand factor (VWF:CBA): detection of von Willebrand's Disease (VWD), and discrimination of VWD subtypes, depends on collagen source.  Thromb Haemost. 2000;  83 127-135
• 15 Ewenstein B M. von Willebrand's disease.  Annu Rev Med. 1997;  48 525-542
• 16 Sadler J E, Mannucci P M, Berntorp E et al.. Impact, diagnosis and treatment of von Willebrand disease.  Thromb Haemost. 2000;  84 160-174
• 17 Mannucci P M. How I treat patients with von Willebrand disease.  Blood. 2001;  97 1915-1919
• 18 Berntorp E, Nilsson I M. Use of a high-purity factor VIII concentrate (Hemate P) in von Willebrand's disease.  Vox Sang. 1989;  56 212-217
• 19 Cumming A M, Fildes S, Cumming I R, Wensley R T, Redding O M, Burn A M. Clinical and laboratory evaluation of National Health Service factor VIII concentrate (8Y) for the treatment of von Willebrand's disease.  Br J Haematol. 1990;  75 234-239
• 20 Mannucci P M, Chediak J, Hanna W et al.. Treatment of von Willebrand disease with a high-purity factor VIII/von Willebrand factor concentrate: a prospective, multicenter study.  Blood. 2002;  99 450-456
• 21 Lillicrap D, Poon M-C, Walker I, Xie F, Schwartz B A. Efficacy and safety of the factor VIII/von Willebrand factor concentrate, Haemate-P/Humate-P: ristocetin cofactor unit dosing in patients with von Willebrand disease.  Thromb Haemost. 2002;  87 224-230
• 22 Menache D, Aronson D L. New treatments of von Willebrand disease: plasma derived von Willebrand factor concentrates.  Thromb Haemost. 1997;  78 566-570
• 23 Chang A C, Rick M E, Ross Pierce L, Weinstein M J. Summary of a workshop on potency and dosage of von Willebrand factor concentrates.  Haemophilia. 1998;  4(suppl 3) 1-6
• 24 Lawrie A S, Harrison P, Armstrong A L, Wilbourn B R, Dalton R G, Savidge G F. Comparison of the in vitro characteristics of von Willebrand factor in British and commercial factor VIII concentrates.  Br J Haematol. 1989;  73 100-104
• 25 Mannucci P M, Tenconi P M, Castaman G, Rodeghiero F. Comparison of four virus-inactivated plasma concentrates for treatment of severe von Willebrand disease: a cross-over randomized trial.  Blood. 1992;  79 3130-3137
• 26 Fricke W A, Lamb M A, Rastogi S C. Standards for assay of von Willebrand factor concentrates: a collaborative study.  Thromb Haemost. 1993;  70 351-356
• 27 Chang P, Aronson D L. Plasma derived von Willebrand factor preparations: collagen binding and ristocetin cofactor activities.  Thromb Haemost. 1997;  78 930-933
• 28 Favaloro E J, Bukuya M, Martinelli T et al.. A comparative multi-laboratory assessment of three factor VIII/von Willebrand factor concentrates.  Thromb Haemost. 2002;  87 466-476
• 29 Barrowcliffe T W, Raut S, Sands D, Hubbard A R. Coagulation and chromogenic assays of factor VIII activity: general aspects, standardization and recommendations.  Semin Thromb Hemost. 2002;  28 247-255
• 30 Neugebauer B M, Goy C, Budek I, Seitz R. Comparison of two von Willebrand factor collagen-binding assays with different binding affinities for low, medium and high multimers of von Willebrand factor.  Semin Thromb Hemost. 2002;  28 139-147
• 31 Neugebauer B M, Volkers P, Seitz R. Willebrand factor potency determination by collagen binding assay. A collaborative study for the establishment of a European Pharmacopoeia method.  Pharmeuropa. 2002;  14 315-327