Heparin and factor VIII.

Abstract

New approaches and techniques for improving source material collection and factor VIII production at Blood Bank level have been reported recently. Heparin has shown to be of great importance in increasing both yield and stability of factor VIII in the purification and concentration process. Work has been done to develop on a routine scale a heparin double cold‐precipitation technique for the production of freeze‐dried high yield purified factor VIII concentrate. As a spin‐off of the method red cell concentrate (RCC) and cryosupernatant plasma (SDP), both containing small amounts of heparin besides the standard CPDA‐1 anticoagulant, are recovered for clinical use. Results of the tests done:RCC ‐ in vitro: Normal Adenosin Tri‐Phosphate (ATP), 2 3 Di‐Phospho‐Glycerate (DPG) and shelf‐life, Heparin 0.7 IU/ml (±0.3).‐ in vivo: Normal half 51Cr‐survival, no side effects.SDP ‐ in vitro: Protein and chemical analysis normal, shelf‐life normal, Heparin 3.5 IU/ml (±0.7).‐ in vivo: No side‐effects, mild effect on activated Partial Thromboplastin Time (aPTT) 5 minutes post transfusion.Factor VIII concentrate ‐ in vitro: Yield 56.2 (±8.2) percent, purity 0.8 (±0.15) FVIII:C IU/mg protein, potency 25.2 (±3.2), FVIII:C IU/ml Heparin 6.2 (±0.7) IU/ml.‐ in vivo: Normal recoveries and half‐lifes after injection of 15–20 IU/kg in 4 severe hemophilia A patients.This heparin small pool high yield principle is expected to have great impact on availability, access to and safety of adequate treatment in hemophilia in the future.