[Sickle cell anemia and the affinity of the blood for oxygen].

Blood affinity for oxygen is reduced in patients with homozygous HbS disease. The mechanisms were related to polymerisation and sickling process. In the HbS blood, P50 values were related to the percentage of sickling, the effect of prior deoxygenation on P50 measurement was established. This work underlines the influences of experimental conditions on the determination of sickle cell blood affinity and the difficulties inherent in the evaluation of in vivo oxygen transport in sickle cell disease.