Measurement of vitamin B12-binding proteins of plasma. II. Interpretation
of patterns in disease
JA Begley and CA Hall
The technique described in the preceding paper was applied to 12 abnormal
sera selected for their increase in one or more B12-binding proteins. Even
in the presence of large amounts of R-type binder, the ammonium sulfate
technique gave a reliable separation of R binding proteins from TC II.
Measurement of the TC II in abnormal sera gave results identical to those
obtained by the more standard gel filtration. The R binders of four
subjects with myeloproliferative disease were further separated into
alpha2-R and alpha1-R. The pattern of B12 binding of polycythemia vera (PV)
was an exaggeration of the normal pattern. Binding to alpha2-R was three to
four times that to alpha1-R, although the total amounts bound to both were
increased. In chronic myelogenous leukemia (CML), both alpha2-R and
alpha1-R were also increased, but in contrast to binding in normal sera,
alpha1-R predominated. In order to interpret the findings, either whole
serum R or alpha1-R and alpha2-R from patients with myeloproliferative
disease were subject to isoelectric focusing. Alpha2-R consisted pricipally
of components isoelectric at pH 2.9, 3.0, and 3.1. These components were
present in only minor amounts in normal serum and were somewhat increased
in the serum of PV. These components were very much increased in the serum
of CML and predominated. Alpha2-R consisted of those components isoelectric
at pH 3.4,3.6, and 4.0. These components predominated in the unsaturated
binding capacity of normal sera and that of PV. It was concluded that the
division of plasma R binders into alpha1-R and alpha1-R by the technique
described provided information useful in the study of myeloproliferative
diseases.
Volume 45,
Issue 2,
pp. 287-293,
02/01/1975
Copyright © 1975 by The American Society of Hematology
