Serum Unsaturated B12 Binding Capacity Research Articles

The Transcobalamins in Polycythaemia Vera

The unsaturated B12 binding capacity (UBBC) of the serum and the binding capacity of each of the 3 vitamin B12 binders--the transcobalamins (TC) I, II and III were determined in 21 patients with polycythaemia vera (PV) during the course of the disease and following treatment, using the recently described charged cellulose filter technique. High serum UBBC due to elevated serum TCIII was found in all patients. TCI was moderately elevated in patients who had leucocytosis with a shift to the left. The changes in serum TCIII and UBBC correlated with the activity of the disease. Chemotherapy resulted in a decrease in TCIII and UBBC. The decrease in TCIII and UBBC folowing chemotherapy may be observed before a decrease in the haematocrit and the leucocyte count occurs. Activation of the disease may be assessed by the elevation of TCIII and UBBC. The onset of acute myeloblastic crisis in 1 patient was associated with a decrease in TCIII and TCI levels and a rise in serum TCII. The determination of TCIII and UBBC may be helpful in differentiating true from secondary polycythaemia.

Rapid Charcoal Assay for Intrinsic Factor (IF), Gastric Juice Unsaturated B12 Binding Capacity, Antibody to IF, and Serum Unsaturated B12 Binding Capacity

Abstract The principle of the dialysis assays for intrinsic factor (IF) and antibody to IF was integrated with the demonstration that protein-coated charcoal adsorbs only free and not bound B12, in a single rapid method for 4 separate assays: (1) assay of IF, (2) assay of gastric juice unsaturated B12 binding capacity, (3) assay of serum antibodies to IF and (4) assay of serum unsaturated B12 binding capacity. The method is sensitive, accurate, reproducible, and can easily be completed within an hour. The simplicity and ready availability of reagents and equipment lends itself to ready adoption in any clinical laboratory using radioisotopes. The charcoal particle is considered as a solid microsponge, and its coat of albumin, other protein, carbohydrate, or other large molecule as a molecular sieve surrounding the sponge. The whole constitutes a system of "instant dialysis," with a wide range of applications in the separation of large from small molecules.