Growth after bone marrow transplantation in young children conditioned with chemotherapy alone.

Short stature is a potential side-effect of BMT, brought about by the conditioning protocol and/or the complications of BMT. This study evaluates the effects of conditioning by chemotherapy, and BMT complications on growth. Thirty children conditioned for BMT by chemotherapy alone (cyclophosphamide and busulfan) were classified according to the occurrence of serious or prolonged complications after BMT: group 1 (n = 12) had no complication, while group 2 (n = 18) did. Fifteen of them were severely growth retarded (< or = -2 s.d.) at BMT, because of their initial disease. At the time of BMT, the two groups had similar ages (1.0 +/- 0.2, s.e.m. year, in group 1 and 1.7 +/- 0.5 year in group 2), height (-1.7 +/- 0.5; -1.8 +/- 0.3 s.d.) and plasma insulin-like growth factor I (IGFI) levels (0.3 +/- 0.1 U/ml in both). Group I grew significantly and their plasma IGFI increased but group 2 did not, as assessed 2 years post-BMT. We conclude that conditioning with chemotherapy alone does not prevent the catch-up growth induced by BMT in young children; the lack of catch-up growth is due to complications occurring after BMT, and the change in plasma IGFI suggests that complications of BMT prevent any increase in plasma IGFI, and thereby catch-up growth.