Effect of different treatment regimes on linear growth and final height in beta-thalassaemia major

The clinical picture of thalassaemia major has changed progressively over the years. Our study is a retrospective analysis of data on growth in a group of patients who have completed puberty spontaneously and have attained their adult height. Our objective was to evaluate the effect of different transfusion regimes and desferrioxamine administration on the growth pattern in beta-thalassaemia major.

We studied 64 patients (28 males and 36 females). The patients were divided into three groups (A, B and C) according to the different transfusion regimes and the schedules of chelating therapy. Group A consisted of 16 patients who were transfused regularly at low haemoglobin levels (on average 8.5 g/dl) from an early age and started subcutaneous chelation therapy during adolescence. Group B consisted of 19 patients who were transfused regularly at high haemoglobin levels (on average 10 g/dl) from an early age and started subcutaneous therapy during childhood. Group C consisted of 29 patients who were transfused regularly at high haemoglobin levels (on average 10.5 g/dl) from an early age and started subcutaneous chelation therapy very early, at a mean age of 2 years. Standard auxological measurements were made at 3-monthly intervals throughout childhood and puberty until adult height was achieved. For group C patients the data on linear growth are provided only until the age of 12 years.

Our study indicates that group A male and female patients did not grow significantly better than those in group B. Group C male and female patients, surprisingly, grew no faster than those who started chelation therapy late in childhood (group A). The most striking feature in the majority of both group A and B patients was reduced spurt in height at puberty. In addition, in both groups, a reduced sitting height due to spinal growth abnormality was found. An inverse correlation between sitting height and serum ferritin levels was observed in group A patients (r = -0.55, P < 0.05), whereas there was a direct correlation in group B patients (r = 0.42, P < 0.05).

These data suggest that an ideal therapeutic regime has yet to be found which avoids the toxic effect of iron overload and on the other hand avoids interference with growth, secondary to desferrioxamine. Therefore we recommend that the growth of thalassaemia patients be monitored routinely at every follow-up visit and documented on growth velocity charts in order to detect early changes in their growth pattern and to establish an appropriate protocol for investigation and treatment.