Introduction. Controversial data on disturbances in mineral homeostasis and bone mass were reported in children with diagnosed untreated acute lymphoblastic leukemia (ALL). Early detection of bone metabolism abnormalities is important for monitoring the effect of therapy on the skeleton. The purpose of this study was to evaluate bone metabolism in children and adolescents with newly diagnosed acute lymphoblastic leukemia by assessing biomarkers of bone cell activity.

Materials and methods. Propeptide of type 1 procollagen (P1NP) and osteocalcin (OC) as bone formation markers and C-terminal telopeptide of type 1 collagen (CTX) and tartrate resistant acid phosphatase 5b (TRAP 5b) as resorption markers were determined in 22 Caucasian children and adolescents (12 boys 4–21 years, 10 girls 4–16 years) with newly diagnosed, untreated ALL and in 22 age- and gender-matched controls.

Results. Bone formation, in particular, and bone resorption were significantly reduced in ALL children and adolescents compared with controls (Me P1NP 51.9 vs. 433.4 μg/L and OC 16.1 vs. 80.5 μg/L; p < 0.0001; Me CTX 0.454 vs. 1.225 μg/L and TRAP 5b 2.8 vs. 5.6 U/L; p < 0.001). P1NP positively correlated with OC (r = 0.56; p = 0.01) and CTX correlated with TRAP 5b (r = 0.54; p = 0.02) in children and adolescents with ALL. Median P1NP and OC concentrations in ALL children (4–9 years) were dramatically reduced compared with the healthy ones (10-fold and 9-fold respectively), whereas in adolescents with ALL (10–21 years) both bone formation markers were reduced in a lesser degree in comparison with the healthy adolescents.

Conclusions. Acute lymphoblastic leukemia influences bone metabolism which is strongly related to the age of onset. More significant disturbances in bone turnover, particularly in bone formation (suppression of collagen synthesis), are observed in children with untreated ALL in comparison with adolescents with ALL.