Bone turnover markers, osteoprotegerin and RANKL cytokines in children with cystic fibrosis
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Published on: March 15, 2018
Insights
Children with cystic fibrosis (CF) show lower bone formation and higher bone resorption markers. This imbalance, linked to lower osteoprotegerin (OPG) and higher receptor activator of nuclear factor κB ligand (RANKL), may increase fracture risk.
Area of Science:
- Pediatric Endocrinology
- Bone Metabolism
- Cystic Fibrosis Research
Background:
- Cystic Fibrosis (CF) is associated with reduced bone mineral density and increased fractures in adults.
- Multifactorial causes include chronic inflammation, malnutrition, and delayed puberty.
- Early bone loss mechanisms in pediatric CF require further investigation.
Purpose of the Study:
- To evaluate bone metabolism markers in children with CF.
- Specifically, to assess the balance of osteoprotegerin (OPG) and receptor activator of nuclear factor κB ligand (RANKL).
- To identify potential early indicators of bone disease in pediatric CF patients.
Main Methods:
- A cohort of 35 children with CF (ages 5-9) and 35 healthy controls was studied.
- Serum levels of fat-soluble vitamins (A, D, E) were quantified.
- Bone metabolism markers, including OPG and RANKL, were measured using immunoenzymatic assays.
Main Results:
- CF children exhibited lower levels of vitamins A, D, and E compared to controls.
- A significant decrease in the bone formation marker osteocalcin was observed in CF patients.
- CF children showed significantly lower OPG and markedly higher RANKL levels, resulting in a reduced OPG/RANKL ratio.
Conclusions:
- Pediatric CF patients exhibit an imbalance in bone turnover, favoring resorption.
- Elevated serum RANKL and diminished OPG levels in CF children are associated with heightened bone resorption.
- These findings suggest a potential mechanism for early bone loss in children with cystic fibrosis.
Purpose:
Some scientific studies show decreased bone mineral density and increased fracture frequency in adult patients with cystic fibrosis (CF). The mechanism for early bone loss in CF patients are multifactorial: chronic pulmonary inflammation, malnutrition, reduced physical activity, delayed pubertal maturation. The aim of this study was to assess bone metabolism markers with special attention paid to osteoprotegerin (OPG) and receptor activator of nuclear factor κB ligand (RANKL) balance in CF children.
Material And Methods:
The study included 35 children with diagnosed CF and 35 healthy controls aged 5-9 years (median 7.0 years). Serum levels of fat soluble vitamins were measured by chemiluminescence (vitamin D) and HPLC (vitamins A, E) methods. Concentrations of bone metabolism markers were determined by immunoenzymatic assay.
Results:
Mean levels of fat soluble vitamins (A, D, E) were lower in patients with CF compared to controls. In CF children we observed a significant (p<0.01) decrease in concentration of bone formation marker (osteocalcin) and similar bone resorption markers (CTX, TRACP5b) in comparison with healthy children. The serum level of OPG was significantly lower (p<0.05) and RANKL nearly 2-fold higher in patients with CF than in the healthy ones. The ratio of OPG to RANKL was about 2-fold lower in children with CF compared to healthy peers (p<0.01).
Conclusion:
In CF children, an imbalance between bone formation and resorption processes occurs. An increase serum RANKL concentration coexisting with lower levels of OPG may be associated with intensification of bone resorption.
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