Red cell changes in hyperthyroidism.
The Coulter 'S' red cell profile was studied prospectively in 100 untreated non-anaemic hyperthyroid patients and followed up in 52 of them until they had become euthyroid with radio-iodine or carbimazole treatment. Serial haematological data were also obtained in 23 hyperthyroid patients during treatment with beta-adrenoreceptor blocking drug alone. The most significant finding was a low mean corpuscular volume (MCV) which was invariably present throughout the hyperthyroid state. Treatment with beta-adrenoreceptor blocking drugs did not significantly alter any of the red cell parameters. On the other hand, the MCV increased and was restored to normal with radio-iodine or carbimazole treatment although there was a lag period of about 6--8 weeks between achieving the euthyroid state and the normalisation of this red cell index. While none of the patients were aneaemic, the haemoglobin level rose significantly following effective anti-thyroid treatment. It is suggested that measurement of the MCV may have a useful role in the diagnosis of hyperthyroidism. 2 possible mechanisms leading to the observed red cell changes in hyperthyroidism are postulated.
D000293:Adolescent; D000328:Adult; D000368:Aged; D002231:Carbimazole / Q000627:therapeutic use; D004909:Erythrocyte Indices; D005260:Female; D005500:Follow-Up Studies; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood* / Q000188:drug therapy; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D008790:Metoprolol / Q000627:therapeutic use; D008875:Middle Aged; D011433:Propranolol / Q000627:therapeutic use
D006454:Hemoglobins; D007457:Iodine Radioisotopes; D002231:Carbimazole; D011433:Propranolol; D008790:Metoprolol