Immunologic characterization of canine factor VIII
RE Benson and WJ Dodds
Canine factor VIII (FVIII) preparations isolated from cryoprecipitates by
gel chromatography were pooled to provide one batch of antigen for
simultaneous immunization of two rabbits and a goat. The goat and rabbit
antisera had similar FVIII-neutralizing titers, but the latter had seven to
ten times more precipitating titer for FVIII-related antigen (FVIII-RA).
Absorption with material low in FVIII had little effect on the
precipitating titer of the rabbit antibody, but it abolished the
precipitating capacity of the goat antibody and caused a 20% reduction in
the neutralizing titer of both antisera. Results obtained in the Laurell
assay with the two different antisera were similar. This finding was true
whether the FVIII-RA levels were reduced, normal, or elevated, as well as
for heat-treated and frozen- thawed plasmas. Both antisera were neutralized
by the same canine plasma to a similar extent. Analysis of FVIII
concentrates by crossed immunoelectrophoresis suggested that canine
FVIII-RA was heterogeneous, with slow-and fast-migrating components. The
presence of more than one antigenic site on the FVIII complex was also
supported by the disparity between the FVIII-neutralizing and
-precipitating titers of goat antiserum and by the demonstration that
FVIII-RA, FVIII-neutralizing antigen, and procoagulant activity varied
independently.
Volume 48,
Issue 4,
pp. 521-529,
10/01/1976
Copyright © 1976 by The American Society of Hematology
