Studies on Abnormal Hemoglobins : V. The Distribution of Type S (Sickle Cell) Hemoglobin and Type F (Alkali Resistant) Hemoglobin within the Red Cell Population in Sickle Cell Anemia

1. By transfusing sickle cell anemia erythrocytes with a relatively high concentration of F hemoglobin into normal recipients, it was demonstrated that the disappearance rates of the transfused cells and of their alkali resistant pigment consistently showed great discrepancies. These observations suggest an unequal distribution of the F pigment within the erythrocyte population. A nonuniform distribution of F hemoglobin could also be detected in vitro by exposing sickle cell anemia bloods to mechanical trauma for a longer period of time. The cells most resistant to trauma contained a higher percentage of F hemoglobin than the original blood specimen.

2. The red cell population of patients with sickle cell anemia seems to be composed of three main fractions: (1) cells containing S hemoglobin and no or little F hemoglobin, (2) cells containing both pigments and (3) cells containing F pigment with no or little S hemoglobin.

3. The erythrocytes carrying mostly S hemoglobin have the shortest life span, whereas the red cells containing mostly F hemoglobin have the longest survival time.

4. The significance of these findings in regard to clinical and genetic aspects of sickle cell anemia is discussed. No direct correlation is demonstrable in an individual patient between the absolute amounts of either type S or type F hemoglobin and the severity of the anemia. The latter depends on the variable size of the portion of red cells containing mostly S hemoglobin, and also on the ability of the marrow to replace this particular fraction.