title: Pediatric solid organ transplantation and osteoporosis: a descriptive study on bone histomorphometric findings.
abstract: BACKGROUND
  Organ transplantation may lead to secondary osteoporosis in children. This study characterized bone histomorphometric findings in pediatric solid organ transplant recipients who were assessed for suspected secondary osteoporosis.
  
  
  METHODS
  Iliac crest biopsies were obtained from 19 children (7.6-18.8 years, 11 male) who had undergone kidney (n = 6), liver (n = 9), or heart (n = 4) transplantation a median 4.6 years (range 0.6-16.3 years) earlier. All patients had received oral glucocorticoids at the time of the biopsy.
  
  
  RESULTS
  Of the 19 patients, 21 % had sustained peripheral fractures and 58 % vertebral compression fractures. Nine children (47 %) had a lumbar spine BMD Z-score below -2.0. Histomorphometric analyses showed low trabecular bone volume (< -1.0 SD) in 6 children (32 %) and decreased trabecular thickness in 14 children (74 %). Seven children (37 %) had high bone turnover at biopsy, and low turnover was found in 6 children (32 %), 1 of whom had adynamic bone disease.
  
  
  CONCLUSIONS
  There was a great heterogeneity in the histological findings in different transplant groups, and the results were unpredictable using non-invasive methods. The observed changes in bone quality (i.e. abnormal turnover rate, thin trabeculae) rather than the actual loss of trabecular bone, might explain the increased fracture risk in pediatric solid organ transplant recipients.
authors.affiliation: Bone and Cartilage Research Unit (BCRU), University of Eastern Finland, POB 1627, Mediteknia Building, 70211, Kuopio, Finland, inari.tamminen@uef.fi.
authors.forename: Inari S
authors.initials: IS
authors.lastname: Tamminen
authors.forename: Helena
authors.initials: H
authors.lastname: Valta
authors.forename: Hannu
authors.initials: H
authors.lastname: Jalanko
authors.forename: Sari
authors.initials: S
authors.lastname: Salminen
authors.forename: Mervi K
authors.initials: MK
authors.lastname: Mäyränpää
authors.forename: Hanna
authors.initials: H
authors.lastname: Isaksson
authors.forename: Heikki
authors.initials: H
authors.lastname: Kröger
authors.forename: Outi
authors.initials: O
authors.lastname: Mäkitie
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D001842:Bone and Bones / Q000473:pathology*; D002113:Calcification, Physiologic; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D050723:Fractures, Bone / Q000453:epidemiology; D005938:Glucocorticoids / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D006128:Growth / Q000502:physiology; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D008297:Male; D016377:Organ Transplantation / Q000009:adverse effects*; D010024:Osteoporosis / Q000453:epidemiology / Q000209:etiology / Q000473:pathology*; D011627:Puberty / Q000502:physiology
chemical_list: D005938:Glucocorticoids; D007166:Immunosuppressive Agents