Abstract
Oxygen affinity studies in a splenectomized patient with sporadically occurring Hb Köln disease revealed high whole blood oxygen affinity (P50 O2 17.6 mm Hg) with increased 2, 3-diphosphoglycerate (DPG), low ATP, and normal RBC ΔpH. Isolated electrophoretically slow migrating Hb Köln had a high oxygen affinity, decreased Hill’s number, and normal DPG reactivity. Functional evidence for hybrid tetramers with normal mobility is presented. Partial deoxygenation may play a role in the denaturation of the Hb Köln molecule and thus account for a higher oxygen affinity (low P50 O2), measured by the mixing technique, than the actual values for P50 that exist in vivo. Increased oxygen affinity and decreased P50 O2 would result in increased erythropoiesis and account for a well-compensated hemolytic process in this patient with a normal red cell mass and normal values of hemoglobin.
