Tissue Oxygenation in Patients with Hemoglobinopathy H

To evaluate the degree of tissue hypoxia in patients with hemoglobinopathy H disease, whole blood oxygen affinity was estimated and analyzed in 33 patients. Twenty patients with iron deficiency anemia, matched for degree of anemia, served as controls. The results were as follows: Whole blood oxygen equilibrium curves of patients with HbH disease are biphasic because of a combination of the rectangular hyperbolic curve of HbH and the normal sigmoid curve of HbA and are shifted toward the left (P50 3.66 +/- 0.33 kPa). Patients with iron deficiency anemia have right-shifted oxygen equilibrium curves (P50 4.02 +/- 0.13 kPa) compared with normal. Oxygen release to the tissues in HbH disease is decreased (1.4 +/- 0.3 mmol/L) as compared with iron-deficient patients (1.6 +/- 0.2 mmol/L) with a similar degree of anemia. Red cell indices vary between the two groups. In patients with HbH disease the mean corpuscular hemoglobin concentration was 268 +/- 17 g/L as compared with 294 +/- 18 g/L in iron deficiency anemia. These findings indicate that whole blood oxygen affinity is a reliable index of tissue oxygenation in patients with hemoglobinopathy H.