Hemoglobin synthesis in BFU-E colonies derived from transfused blood in a sickle cell anemia patient.

In an in vitro progenitor cell culture system, a significant amount of normal hemoglobin (Hb A) synthesis was observed in a transfused sickle cell anemia (SS) patient, indicating the contribution of stem cells obtained from the normal donor's blood cells. As this study was done long after the last blood transfusion (greater than 100 days), the survival of the donor's stem cells would indicate their repopulating the recipient's bone marrow. On extending the study to a few other transfused SS patients who had received multiple blood transfusions at frequent intervals, no such synthesis of Hb A was observed. A loss of repopulating ability of the donor's stem cells with frequent transfusions at short intervals is suggested as a possible explanation, with a gradual development of immune response against these cells as a second possibility. The differences in the survival of the donor's stem cells would thus appear to have some reflection on the frequency of blood transfusions required by an individual patient.