Bone Abstracts

In children and adolescents with acute lymphoblastic leukemia (ALL), low bone mineral density (BMD) and increased risk of fractures can be observed at diagnosis and/or during treatment.

This prospective study was aimed to evaluate BMD and bone turnover in patients with a new diagnosis of ALL, treated with an international protocol (AIEOP BFM ALL 2009) (*), based on high-dose steroids and chemotherapeutic drugs.

Inclusion criteria were age 3–18 years, no other diseases, no previous use of steroids or chemotherapy.

During 15 months, out of 54 children and adolescents consecutively diagnosed with ALL, 30 subjects were enrolled in the study (median age 8 years; 13 males; eight pubertal).

We present the preliminary results on bone mineral density (BMD, measured by dual-energy x-ray absorptiometry), and bone turnover markers (C-terminal telopeptide (CTx), osteoprotegerin (OPG), receptor activator of nuclear factor kappa-B ligand (RANKL)), at baseline and at start of the reinduction phase (about 6 months after diagnosis).

At baseline, the mean level of 25-OH vitamin D was 17 ng/ml (normal in 41.3% of patients, low in 58.7/%), and one previous appendicular fracture was reported by one patient.

During the study, CTx serum levels increased from 906.7 pg/ml (baseline) to 1.485 pg/ml (reinduction phase) (P=0.005). The RANKL/OPG ratio (probably investigated for the first time in pediatric ALL) was higher than normal, but decreased from baseline to reinduction phase (baseline 59.2; reinduction 38.1; normal 28±11).

Bone mineral apparent density (BMAD) z-score at lumbar spine and BMD z-score at total body less head (TBLH) were already decreased at baseline in 46.7 and 22% of children respectively, and continued to decrease during therapy, especially TBLH (P=0.006). Five patients had sustained one incident appendicular fracture by start of reinduction phase.

In conclusion, imbalance of RANKL/OPG system, with consequent low values of spine and total body BMD and increased bone resorption were present at diagnosis and during the first 6 months of treatment in children and adolescents with ALL. Further studies are needed to confirm these findings.

(*) AIEOP=Associazione Italiana di Ematologia Oncologia Pediatrica; BFM=Berlin Frankfurt Muenster.

Disclosure: The authors declared no competing interests.