Growth after hematopoietic stem cell transplantation in children with acute myeloid leukemia

Abstract

Previous studies have shown that hematopoietic stem cell transplantation (HSCT) may result in growth impairment. The purpose of this study was to evaluate the growth during 5 yr after HSCT and to determine factors that influence final adult height (FAH). We retrospectively reviewed the medical records of acute myeloid leukemia (AML) patients who received HSCT. Among a total of 37 eligible patients, we selected 24 patients who began puberty at 5 yr after HSCT (Group 1) and 19 patients who reached FAH without relapse (Group 2). In Group 1, with younger age at HSCT, sex, steroid treatment, hypogonadism and hypothyroidism were not significantly associated with growth impairment 5 yr after HSCT. History of radiotherapy (RT) significantly impaired the 5 yr growth after HSCT. Chronic graft-versus-host disease (cGVHD) only temporarily impaired growth after HSCT. In Group 2, with younger age at HSCT, steroid treatment and hypogonadism did not significantly reduce FAH. History of RT significantly reduced FAH. Growth impairment after HSCT may occur in AML patients, but in patients without a history of RT, growth impairment seemed to be temporary and was mitigated by catch-up growth.

Keywords: Acute Myeloid Leukemia; Growth; Hematopoietic Stem Cell Transplantation; Radiotherapy; Total Body Irradiation.

Fig. 1

Schematic description of classification of 97 acute myeloid leukemia patients. HSCT, hematopoietic stem cell transplantation, FAH, final adult height.

Fig. 2

Growth of the RT patients. Height Z-scores of RT patients at yearly intervals after HSCT were described (S1, S2 and S3, CI subjects; S4, S5 and S6, CSRT subjects; S7, TBI subject). Dotted lines indicate GH treatment period. After starting the treatment, height Z-scores increased or stopped decreasing. One RT patient (S4) seemed to show catch-up growth after 5 yr, but this growth was pubertal growth. RT, radiotherapy; HSCT, hematopoietic stem cell transplantation; GH Tx, growth hormone treated subject (+, treated; -, non-treated); CI, cranial irradiation; CSRT, craniospinal radiotherapy; TBI, total body irradiation; Group 1, patients whose puberty began at least 5 yr after HSCT; Group 2, patients who reached final adult height without relapse.

Fig. 3

Scatterplots of height Z-scores at yearly intervals after HSCT with linear regression lines and smooth curved fit lines with standard error intervals (Group 1). A point indicates the height Z-score 0 to 5 yr after HSCT for one patient. Jagged lines indicate smooth curved fit lines. Pink-colored points and smooth curved fit lines indicate the data of non-RT patients in (B, C). Note that the smooth curved fit line shows that only the height of RT subjects (blue) among the cGVHD and steroid-treated patients continues to decrease in the 5 yr after HSCT. RT, radiotherapy; cGVHD, chronic graft-versus-host disease; HSCT, hematopoietic stem cell transplantation.

Fig. 4

Mean height Z-score at HSCT, at final adult height and mean target height Z-score comparing between non-RT and RT patients (Group 2). HSCT, hematopoietic stem cell transplantation; RT, radiotherapy.