Bone histomorphometric changes in children with rheumatic disorders on chronic glucocorticoids

Area of Science:

• Pediatric Rheumatology
• Bone Biology
• Skeletal Health

Background:

• Rheumatic diseases increase fracture risk in children.
• Bone micro-architecture in pediatric rheumatic diseases is not well understood.
• Glucocorticoids used for rheumatic diseases can negatively impact bone health.

Purpose of the Study:

• To characterize bone micro-architecture in children with rheumatic diseases on chronic glucocorticoids.
• To investigate associations between bone micro-architecture and clinical/radiological factors.
• To assess bone mineralization in this pediatric cohort.

Main Methods:

• Trans-iliac bone biopsies were performed on children with rheumatic diseases and vertebral fractures.
• Histomorphometric analysis evaluated trabecular bone structure and osteoid parameters.
• Quantitative backscattered electron imaging (qBSE) assessed bone mineralization.

Main Results:

• Children showed decreased trabecular thickness, osteoid thickness, and osteoblast surface, with increased trabecular separation compared to norms.
• Trabecular deficits correlated with glucocorticoid dose, height, and BMI Z-scores.
• Bone mineralization was heterogeneous and hypermineralized, linked to cumulative glucocorticoid exposure.

Conclusions:

• Children with rheumatic diseases and vertebral fractures exhibit abnormal bone micro-architecture and mineralization.
• These bone abnormalities are associated with chronic glucocorticoid use.
• Findings highlight the detrimental effects of glucocorticoids on pediatric bone health in rheumatic diseases.