The Fate of Prothrombin and Factors VIII, IX and X Transfused to Patients Deficient in these Factors

T he treatment of patients with coagulation defects consists of an attempt temporarily to replace in their blood the factor they lack. This is achieved by giving whole plasma or concentrates of the appropriate factor prepared from human or animal blood. There is now no reasonable doubt that this treatment is effective. With increasing precision of the methods used to assay the different factors it is becoming possible to relate the blood level achieved in the patient to the dose of material administered and to study the rate of disappearance of the factor from the patient's circulation. Accumulation of this information for all treated patients should improve treatment. If bleeding is related to the concentration of a particular factor in the patient's blood, it is clearly important to be able to predict what concentration is likely to be reached after a given dose and to predict how long it is likely to be maintained. If the response of patients to therapeutic material prepared by different methods is not the same, this again is important because allowances must be made for the variations in calculating the effective dose.
The purpose of the present communication is to present the results of studies recently made at Oxford during the routine treatment of patients admitted to the Oxford hospitals. Assays were made of the blood levels of the relevant factor before and after the administration of a variety of therapeutic materials. The blood levels achieved were related to the calculated amount of the factor given and the rate of its disappearance from the blood was recorded. In this study the case records are not given in detail, nor is there any discussion of the therapeutic effectiveness of treatment in any particular case.