DISAPPEARANCE RATE OF CONCENTRATED PROCONVERTIN EXTRACTS IN CONGENITAL AND ACQUIRED HYPOPROCONVERTINEMIA*

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Abstract
Extracts containing 35 to 88 times the proconvertin concentration of normal human plasma were produced by aluminum hydroxide adsorption of citrated plasma, elution with phosphate buffer and precipitation of the protein in the eluate at pH 5.6 with 40% ethanol at -5oC. Following 16 injections of these extracts into 9 human subjects, net increases in proconvertin of from 46% to 160% were achieved. In 1 normal subject a disappearance curve with a single exponential component having a half-time of 230 min. was found. In 1 2 mildly deficient and 1 moderately deficient congenital hypo-proconvertinemic patients disappearance curves with 2 exponential components were found. The half-time of the first component was 18 to 30 min. and that of the second was 210 to 240 min. In 4 severely deficient congenital hypoproconvertinemic patients, 1 patient with severe liver disease and 1 normal subject receiving oral Warfarin, disappearance curves with 2 exponential components were found. The half-time of the first component was 11 to 17 min. and that of the second 85 to 120 min. The average net increase in proconvertin at T = O was 104% of the predicted value in the severely''deficient patients and 159% in the normal, mild and moderately deficient patients. Intravenous administration of the extract on 5 occasions to 2 patients with congenital hypoproconvertinemia resulted in prompt cessation of gingival bleeding, epistaxis and rectal bleeding.