title: Increased osteoblast and osteoclast indices in individuals with systemic mastocytosis.
abstract: Indolent systemic mastocytosis (ISM) can trigger bone loss. However, the clinical relevance of different mast cell infiltration patterns for bone remains to be clarified. Here, we report increased bone turnover in individuals with ISM, and its extent is rather related to the type of mast cell distribution within the bone marrow than to the presence or absence of cutaneous manifestations.
  
  
  BACKGROUND
  It is well established that ISM can trigger osteopenia or osteoporosis. However, neither the clinical relevance of the infiltration pattern of mast cells within the bone marrow nor the impact of the presence or absence of cutaneous mast cell infiltration has been elucidated.
  
  
  METHODS
  We retrospectively analysed 300 cases with histologically proven ISM of the bone marrow and performed quantitative histomorphometry for a subgroup of 159 patients that did not receive any treatment before the biopsies were taken. Most importantly, since 66 % of the patients displayed ISM without the characteristic skin lesions, we were able to compare ISM with or without cutaneous manifestation.
  
  
  RESULTS
  We found that both forms of ISM were not only characterized by a decreased trabecular bone mass but also by an increased number of osteoclasts and osteoblasts. Interestingly, when we analysed these data in relation to mast cell distribution, we found that the bone cell numbers in cases with mast cell granulomas were significantly increased compared to cases with diffuse mast cell distribution. Moreover, evidence of increased bone turnover was also found in 16 patients displaying osteosclerosis.
  
  
  CONCLUSIONS
  Based on the largest cohort of bone biopsies from patients with ISM analysed so far, we could demonstrate high bone turnover, more specifically increased osteoblast and osteoclast numbers and surface indices, as a cause of the skeletal changes. Moreover, the severity of the bone disease is presumably rather dependent on the amount of mast cells and their distribution within the bone marrow irrespective of the presence or absence of cutaneous involvement.
authors: Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany.
authors: S
authors: S
authors: Seitz
authors: F
authors: F
authors: Barvencik
authors: T
authors: T
authors: Koehne
authors: M
authors: M
authors: Priemel
authors: P
authors: P
authors: Pogoda
authors: J
authors: J
authors: Semler
authors: H
authors: H
authors: Minne
authors: M
authors: M
authors: Pfeiffer
authors: J
authors: J
authors: Zustin
authors: K
authors: K
authors: Püschel
authors: C
authors: C
authors: Eulenburg
authors: T
authors: T
authors: Schinke
authors: M
authors: M
authors: Amling
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D001854:Bone Marrow Cells / Q000473:pathology; D016723:Bone Remodeling / Q000502:physiology; D002452:Cell Count; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D008407:Mast Cells / Q000473:pathology; D034721:Mastocytosis, Systemic / Q000453:epidemiology / Q000473:pathology* / Q000503:physiopathology; D008875:Middle Aged; D010006:Osteoblasts / Q000473:pathology*; D010010:Osteoclasts / Q000473:pathology*; D015995:Prevalence; D012189:Retrospective Studies; D017678:Sex Distribution
chemical_list: D015415:Biomarkers