We describe a rare set of monozygotic twins with coexistent sickle cell anemia and αalpha;alpha; thalassemia who have asynchronous painful crises of different frequency and severity. Studies include measurements of cell deformability and other hemorheologic tests, cell density distribution, the percentage of irreversibly sickled cells, adherence of red cells to endothelial cells, membrane he me and membrane free iron, calcium containing internal vesicles and serum antioxidants. Results of these studies, including estimates of organ damage (bone, spleen, retina), were similar except for an increase in red cell membrane free iron in the patient with more frequent and severe painful crises. The study supports the concept that non-inherited factors are important contributors to the frequcncy and severity of painful crises in sickle cell anemia.
Bibliographical noteFunding Information:
Supported in part by NIH Research Grant ROI-HL-27477 (PW,RAS,MPW), NIH Research Grants HL 15162 (HJM), HL 15722 (HJM), NIH Grant HL-30160 (RPH) and an award from the AHA-GLAA (#537 IG) HJM.