Further Experience with a Concentrate Containing Human Antihaemophilic Factor*

The in vivo Longevity of Antihaemophilic Factor (Factor VIII)

“…Prior extensive studies by Blombffck (1958) and Blombffck and Nilsson (1958) using a similar fraction of human plasma have also demonstrated the clinical value of the fraction in attaining high AHF levels in haemophhacs in the treatment of severe haemorrhage or preparation for surgery. Experience with a concentrate containing human antihaemophilic factor derived by an entirely different method has also been reported (Kekwick and Wolf, 1957;Maycock et al, 1963), equally successful clinical results having been observed. Our own expcrience with the use of fraction I in preparing haemophilic patients for dental extraction and hernia repair, in treating haemarthrosis and haematuria, and in three instances of severe lacerations, has been consistent with the results of the above studies.…”

Red Cell Banking and the Production of a Factor VIII Concentrate

“…The preparation of a pro duct for clinical use was reported in 1957 by Kekwick and Wolf [19], and in a slightly modified form by Holman and Wolf [13], diethyl ether being used as the protein precipitant rather than ethanol ; the successful clinical use of this fraction in the treatment of haemor rhage and the cover of dental extraction has been reported by May-cock et al [22]. Blombäck [2], in 1958, described the preparation, using ethanol, of a Fraction I-O, derived from Cohn Fraction I, which gave a good recovery of Factor VIII and was effective in the treatment of haemophilia [26].…”

Acute anaphylaxis, pulmonary oedema, and intravascular haemolysis due to cryoprecipitate.

“…However, since excluding anti-A from the cryoprecipitate used in this child, no reactions have occurred on four occasions. Maycock et al (1963) have pointed out that reactions appear to be related both to the individual patient and the specific preparation of antihaemophilic globulin.…”

“…All tested batches had a similar potency for both these enzymes, so he suggested that the factor determining whether the patient has a reaction or not is the capacity of the patient's blood to inactivate these enzymes and the rate of inactivation is dependent upon the speed of the injection. Maycock et al, (1963) have shown that reactions are less frequent when the injection is given slowly. We have not investigated this mechanism fully, but it is interesting to note that the level of C'l-esterase inhibitor in the cryoprecipitate used was found to be at the upper limit of the normal range.…”