Contributions to the Optimal Use of Human Blood

Abstract

Abstract. It was observed that during the preparation of normal anti‐D immunoglobulin concentrates by a modified Cohn VI method a considerable loss of anti‐D activity occurred in fraction III. A method was developed to prepare anti‐D immunoglobulin concentrates from fraction III by ethanol fractionation. Three batches were treated on a production scale. An average of 18% of the amount of anti‐D activity present in the original plasma, was recovered, which increased the total yield of anti‐D activity from 44 to 62%. The specific activity of anti‐D in the concentrate thus prepared was 2–3 times higher than that in the normal anti‐D immunoglobulin concentrate. The anti‐D immunoglobulin concentrate prepared from fraction III was diluted with normal immunoglobulin concentrate to reach an anti‐D concentration of 110–120 μg/ml. Using several analytical procedures no essential differences could be demonstrated between this final product and the normal immunoglobulin concentrate. After 8 months of storage at 4°C no significant decrease in anti‐D activity could be demonstrated.