Circulating osteogentic precursor cells in non-hereditary heterotopic ossification

• Published in: Bone (New York, N.Y.) Vol. 109; pp. 61 - 64
• Main Authors: Egan, Kevin P., Duque, Gustavo, Keenan, Mary Ann, Pignolo, Robert J.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2018
• Subjects: Adult; Aged; Aged, 80 and over; Brain Injuries, Traumatic - metabolism; Brain Injuries, Traumatic - pathology; Cerebrovascular accident; Circulating osteogenic precursor (COP) cells; Female; Fluorescent Antibody Technique; Heterotopic ossification; Humans; Injury; Male; Middle Aged; Ossification, Heterotopic - metabolism; Ossification, Heterotopic - pathology; Osteogenesis - genetics; Osteogenesis - physiology; Spinal Cord Injuries - metabolism; Spinal Cord Injuries - pathology; Spinal cord injury; Stem Cells - cytology; Stem Cells - metabolism; Stroke - metabolism; Stroke - pathology; Trauma; Traumatic brain injury; Young Adult; Traumatic brain injury; Injury; Cerebrovascular accident; Circulating osteogenic precursor (COP) cells; Heterotopic ossification; Spinal cord injury; Trauma
• ISSN: 8756-3282; 1873-2763; 1873-2763
• DOI: 10.1016/j.bone.2017.12.028

Non-hereditary heterotopic ossification (NHHO) may occur after musculoskeletal trauma, central nervous system (CNS) injury, or surgery. We previously described circulating osteogenic precursor (COP) cells as a bone marrow–derived type 1 collagen+CD45+subpopulation of mononuclear adherent cells that are able of producing extraskeletal ossification in a murine in vivo implantation assay. In the current study, we performed a tissue analysis of COP cells in NHHO secondary to defined conditions, including traumatic brain injury, spinal cord injury, cerebrovascular accident, trauma without neurologic injury, and joint arthroplasty. All bone specimens revealed the presence of COP cells at 2–14 cells per high power field. COP cells were localized to early fibroproliferative and neovascular lesions of NHHO with evidence for their circulatory status supported by their presence near blood vessels in examined lesions. This study provides the first systematic evaluation of COP cells as a contributory histopathological finding associated with multiple forms of NHHO. These data support that circulating, hematopoietic-derived cells with osteogenic potential can seed inflammatory sites, such as those subject to soft tissue injury, and due to their migratory nature, may likely be involved in seeding sites distant to CNS injury. •Non-hereditary heterotopic ossification (NHHO) occurs after musculoskeletal trauma, central nervous system injury, or surgery.•Circulating osteogenic precursor (COP) cells were analyzed as type 1 collagen+CD45+ mononuclear cells.•We performed a tissue analysis of COP cells in NHHO samples secondary to defined precipitating injury or surgery.•All bone specimens revealed the presence of COP cells at 2-14 cells per high power field.•COP cells were localized to fibroproliferative and neovascular lesions of NHHO.•This study provides the first systematic evaluation of COP cells as a contributory histopathological finding in NHHO.