Erythrocyte volume and haemoglobin concentration in haemoglobin H disease: discrimination between the two genotypes.
Erythrocyte volume and haemoglobin concentration in individual red cells from 62 patients with Hb H disease: 37 with H genotype (alpha-thalassaemia 1/alpha-thalassaemia 2) and 25 H/CS genotype (alpha-thalassaemia 1/Hb Constant Spring) were measured using the H*1 haematology analyser. All 25 cases with H/CS genotype, the more severe genotype, had microcytes (red cells with a volume smaller than 60 fl) less than 35% and hypochromic red cells (red cells with haemoglobin concentration less than 28 g/dl) more than 35%. A discriminant function, the ratio between the percentage of hypochromic red cells and the percentage of microcytes (Hypo/Micro), was proposed. Most of the H/CS patients (76%) had Hypo/Micro greater than 2.5 whereas those of H patients (82%) were below 2.5. Red cell volume histograms were also characteristically different between the two genotypes: the H/CS had a peak between 60 and 90 fl while the H genotype showed a peak at or very close to 60 fl, indicating a greater degree of microcytosis. Increased hypochromia with a slight decrease in cell size of H/CS red cells suggests that the poor degree of haemoglobinization has no linkage or very little role in disturbing the synthesis of membrane proteins and their assembly to the plasma membrane.
Bunyaratvej
A
A
Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
Butthep
P
P
Fucharoen
S
S
Saw
D
D
D004909:Erythrocyte Indices; D005838:Genotype; D006454:Hemoglobins / Q000378:metabolism*; D006455:Hemoglobins, Abnormal / Q000378:metabolism; D006801:Humans; D013789:Thalassemia / Q000097:blood* / Q000235:genetics
D006454:Hemoglobins; D006455:Hemoglobins, Abnormal; C035541:Hemoglobin Constant Spring