Correlation Between Various Blood White Cell Pools and the Serum B₁₂-binding Capacities

Twenty-four patients with various hematologic and nonhematologic diseases were studied to correlate the various fractions of the serum B₁₂-binding capacity with the blood granulocyte and leukocyte pools and granulocyte turnover rates. The total blood granulocyte pools correlated well with the serum unsaturated B₁₂-binding capacity, especially with the alpha fraction. At least part of the serum B₁₂-binding protein appears to be derived from the neutrophil and from the eosinophil but little or none from the myeloblast. The serum unsaturated B₁₂-binding capacity appears to be a simple index of the total blood granulocyte pool.