Effect of busulfan and treosulfan on gonadal function after allogeneic stem cell transplantation in children and adolescents with nonmalignant diseases is not exposure-dependent

With an increasing number of young patients surviving into adulthood after hematopoietic stem cell transplantation (HSCT), gonadal dysfunction becomes an important late effect with significant impact on quality of life. In this retrospective study, we evaluated the exposure of busulfan (BU) and treosulfan (TREO) in relation to gonadal function in pediatric patients transplanted for a nonmalignant disease between 1997 and 2018. In the BU cohort, 56 patients could be evaluated and gonadal dysfunction occurred in 35 (63%) patients. Lower BU exposure (cumulative area under the curve cAUC <70 mg*h/L) was not associated with a reduced risk of gonadal dysfunction (OR 0.92 95% confidence interval (CI) 0.25-3.49, p=0.90). In the TREO cohort, 32 patients were evaluable and gonadal insufficiency occurred in 9 patients (28%). Lower TREO exposure (AUC <1750 mg*h/L on day 1) was not associated with a reduced risk of gonadal dysfunction (OR 1.6 95%CI 0.16-36.6, p=0.71). Our data do not support the premise that reduced intensity BU-based conditioning lowers the risk for gonadal toxicity and it is unlikely that TDM-based reduced treosulfan exposure will further limit the risk for gonadal dysfunction.

Late Endocrine Effects After HSCT in Children With Nonmalignant Diseases; A Single Center Cohort Analysis

Endocrine complications are amongst the most frequent late effects after pediatric hematopoietic stem cell transplantation (HSCT) for malignant diseases. Little is known about the prevalence and risk factors of endocrine complications in children transplanted for nonmalignant diseases. This retrospective study included 134 males and 63 females transplanted for a non-malignant disease between 1997 and 2018 with at least 2 years of follow up. Endocrine late effects and growth were evaluated. Gonadal dysfunction was defined as transient or permanent elevation of gonadotropins or hypogonadotropic hypogonadism.

Median age at HSCT was 5.7 years (IQR 2.8-11.3) and median follow-up was 6.2 years (IQR 3.0-10.4). Underlying diseases were inborn errors of immunity (n=74), hemoglobinopathies (n=66) and bone marrow failure (n=57). The majority of patients had received busulfan-based conditioning (46%) or treosulfan-based conditioning (34%).

Gonadal dysfunction occurred in 24/44 (post)pubertal female patients (55%) and was permanent in 19/44 (43%). 22/44 received hormonal substitution, which could be discontinued in 7. In females who received busulfan-based conditioning 16/17 (94%) developed gonadal dysfunction compared to 5/15 (33%) patients with treosulfan-based conditioning; the odds ratio for permanent gonadal dysfunction was 18.7 (3.61-135, p=0.001).

Gonadal dysfunction occurred in 28/66 (post)pubertal male patients (42%) and was permanent in 23/66 (35%). 6/66 received hormonal substitution, which could be discontinued in 1. Gonadal dysfunction was more common in males (post)pubertal at HSCT, 14/21 (67%), compared to those prepubertal at HSCT, 14/45 (31%), p=0.014. 3/15 treated with a treosulfan-based regimen (20%) developed gonadal dysfunction, all transient, versus 19/39 with a busulfan-based regimen (49%), with 2 transient.

29/187 patients developed hypothyroidism (16%), 7 patients received thyroxine treatment (4%). All patients with persistent primary hypothyroidism (n=6) had positive TPO-antibodies.

17 patients received growth hormone treatment and were excluded from analysis. In patients without growth hormone treatment near adult height (NAH) was -1.2 SDS (median, IQR -2.0- -0.3) below mean parental height (MPH) in males and -0.4 SDS (median, IQR -1.6-0.3) in females. NAH below -2 SDS was seen in 13/43 males (30%) and 2/36 females (6%). The majority of these patients already had a height below -2 SDS before HSCT (73%).

In conclusion, this study on late endocrine effects after HSCT in children with nonmalignant diseases indicates frequent gonadal dysfunction, present in 55% of females and 42% of males. In this cohort, risk of gonadal dysfunction in females was higher after busulfan-based conditioning than treosulfan-based conditioning. Careful long-term endocrine follow-up is indicated.

[Growth failure as a symptom of inflammatory bowel disease]

BACKGROUND

Growth failure can be a unique manifestation of untreated intestinal inflammation in children with inflammatory bowel disease (IBD). It can, however, be difficult to diagnose IBD in the absence of symptoms or in the presence of aspecific gastrointestinal symptoms. A delay in diagnosis is a risk factor for lower adult height.

CASE DESCRIPTION

A 15--year-old boy was referred to a paediatric endocrinologist for growth failure and delayed puberty. Additional investigations were performed and he was diagnosed with Crohn's disease.

CONCLUSION

IBD needs to be considered in a child presenting with growth failure and delayed puberty. A detailed medical history of any gastrointestinal symptoms should be taken. One should perform additional investigations according to the guidelines in a patient who fulfils criteria of short stature.

[A newborn with an abnormal position of both legs]

A baby was born with an abnormal position of both legs due to congenital genu recurvatum. This is a rare condition which can appear as an isolated deformity, but is also associated with other musculoskeletal anomalies and syndromes. The prognosis is generally good.