Effects of alpha thalassaemia and haemoglobin F (HbF) level on the clinical severity of sickle-cell anaemia.

Three clinical parameters - average steady-state haematocrit (ASSH), number of crises per year (Cr/Y), and number of transfusions per year (Tx/Y) - were evaluated in 52 patients with sickle-cell anaemia in relation to their foetal haemoglobin (HbF) levels. No correlation was observed between HbF and any of these parameters. A comparison of these three clinical parameters and the alpha globin gene status was also made in 28 of these patients. The relationships between (ASSH) or (Cr/Y) and alpha globin gene status were not significantly different (p > 0.05) but a significantly different value (p < 0.05) was observed between (Tx/Y) and the alpha globin gene status in these patients. It is concluded that, although HbF levels did not affect any of these parameters, alpha thalassaemia deletion significantly reduces the transfusion requirements of these patients.