Heterogeneity of sickle cell disease as shown by density profiles: effects of fetal hemoglobin and alpha thalassemia.
Factors that modify the intraerythrocytic concentration of hemoglobin S may influence the clinical expression of the disease. Using the phthalate ester method, the red blood cell density has been studied as a function of the mean corpuscular hemoglobin concentration. Four parameters have been used to compare the density distribution of the erythrocytes: D50 (median cell density), R60 (density range in which the middle 60% of the cells are found), F4 and F5 (proportion of cells with density greater than 1.110 and 1.120 g/ml). Compared to normal controls the density distribution of sickle red cells is heterogeneous, reproducible for the same patient (except in case of crisis), while different from one to another. The R60 is correlated with the percentage of dense cells, and the highest values for both R60 and dense cells are found when hemoglobin F is less than 10%. The highest values for the median cell density and dense red cells, but not for R60 which is normal, are observed in S/C patients. In sickle cell anemia patients, the median cell density values are not very different from the normal ones. The highest levels of hemoglobin F are found in this median subpopulation of red cells, while they are very low in the densest cells. R60 and the percentage of dense cells are not affected by the association of sickle cell disease with the deletion of one alpha gene. Their values are very near the normal ones in the case of an association with beta thalassemia or homozygous alpha thalassemia.(ABSTRACT TRUNCATED AT 250 WORDS)
D000755:Anemia, Sickle Cell / Q000097:blood* / Q000150:complications / Q000235:genetics; D002499:Centrifugation, Density Gradient; D004912:Erythrocytes / Q000166:cytology; D005319:Fetal Hemoglobin / Q000378:metabolism*; D005838:Genotype; D006801:Humans; D013789:Thalassemia / Q000097:blood* / Q000150:complications / Q000235:genetics
D005319:Fetal Hemoglobin