Hypermineralization and High Osteocyte Lacunar Density in Osteogenesis Imperfecta Type V Bone Indicate Exuberant Primary Bone Formation

摘要: In contrast to "classical" forms of osteogenesis imperfecta (OI) types I IV, caused by a mutation in COL1A1/A2, OI type V is due gain-of-function the IFITM5 gene, encoding interferon-induced transmembrane protein 5, or bone-restricted interferon-inducible (IFITM)-like (BRIL). Its phenotype distinctly differs from IV absence blue sclerae and dentinogenesis imperfecta, occurrence ossification disorders such as hyperplastic callus forearm interosseous membrane ossification. Little known about impact on bone tissue/material level untreated bisphosphonate-treated patients. Therefore, investigations transiliac biopsy samples cohort children (n = 15, 8.7 ± 4 years old) at baseline subset (n = 8) after pamidronate treatment (2.6 average) were performed. Quantitative backscattered electron imaging (qBEI) was used determine mineralization density distribution (BMDD) well osteocyte lacunar density. The BMDD shifted toward higher degree mineralization. most frequently occurring calcium concentration (CaPeak) cortical (Ct) cancellous (Cn) markedly increased (+11.5%, +10.4%, respectively, p < 0.0001) compared healthy reference values. Treatment with resulted only slight enhancement derived sectioned area elevated Ct Cn (+171%, p < 0.0001; +183.3%, p < 0.01; respectively) versus controls. high associated an overall immature primary structure ("mesh-like") visualized polarized light microscopy. summary, material patients hypermineralized, similar other OI. connection lack regular lamellation points exuberant formation alteration remodeling process V. © 2017 American Society for Bone Mineral Research.