Changing blood picture in sickle-cell anaemia from shortly after birth to adolescence.

The blood picture of children with sickle-cell anaemia was found to change with age. The changes were most marked in the first year but the mean level of haemoglobin, haemoglobin F, and target cells fell until adolescence, and irreversibly sickled cells rose. Reticulocytes, Howell Jolly bodies, and normablasts altered little after one year. The fall in haemoglobin F suggested a delayed changeover from fetal to adult haemoglobin production. It was concluded that the blood changes in sickle-cell anaemia were progressive throughout childhood.