Chlamydia pneumoniae and osteoporosis-associated bone loss: a new risk factor?
- 383 Downloads
We found an association between the presence of Chlamydia pneumoniae DNA both in osteoporotic bone tissue and peripheral blood mononuclear cells (PBMCs) and the increase in circulating resorptive cytokines.
Our study was designed to determine whether C. pneumoniae infection may be involved in osteoporosis-associated bone loss.
The study included 59 women undergoing hip joint replacement surgery for femoral neck fracture: 32 with osteoporosis and 27 with osteoarthritis. A total of 118 tissue specimens (59 bone tissues, 59 PBMCs) were examined for C. pneumoniae DNA by real-time polymerase chain reaction (PCR). Serum levels of soluble receptor activator of nuclear factor kappa B ligand (sRANKL), osteoprotegerin (OPG), interleukin (IL)-1β, tumor necrosis factor-α, and IL-6 were also measured.
C. pneumoniae DNA was detected in osteoporotic bone tissue whereas it was not found in non-osteoporotic bone tissue (p < 0.05). A significantly higher rate of C. pneumoniae DNA (p < 0.05) was found in PBMCs of osteoporotic patients than in those of osteoarthritis patients. Among osteoporotic patients, serum sRANKL, IL-1, and IL-6 concentrations as well as sRANKL/OPG ratio significantly differ between patients with bone tissue and PBMCs positive to C. pneumoniae and C. pneumoniae-negative patients.
The association between the presence of C. pneumoniae DNA, both in bone tissue and PBMCs, and the increase in sRANKL/OPG ratio as well as in IL-1β and IL-6 levels observed in osteoporotic patients suggests C. pneumoniae infection as a new risk factor for osteoporosis.
KeywordsC. pneumoniae Osteoporosis sRANKL/OPG IL-6 IL-1 TNF-α
Funding for this study was provided by the Center for Social Disease Research, “Sapienza” University, Rome to R. Sessa.
Conflicts of interest
- 10.Di Pietro M, Tramonti A, De Santis F, De Biase D, Schiavoni G, Sessa R (2012) Analysis of gene expression in penicillin G induced persistence of Chlamydia pneumoniae. J Biological Regulators & Homeostatic Agents 26:277–284Google Scholar
- 11.Bellmann-Weiler R, Martinz V, Kurz K, Engl S, Feistritzer C, Fuchs D, Rupp J, Paldanius M, Weiss G (2010) Divergent modulation of Chlamydia pneumoniae infection cycle in human monocytic and endothelial cells by iron, tryptophan availability and interferon gamma. Immunobiology 215:842–848PubMedCrossRefGoogle Scholar
- 19.WHO Study Group (1994) Assessment of fracture risk and its application to screening for postmenopausal osteoporosis. Report of a WHO Study Group World Health Organ Tech Rep Ser 843:1–129Google Scholar
- 20.Sessa R, Di Pietro M, Schiavoni G, Petrucca A, Cipriani P, Zagaglia C, Nicoletti M, Santino I, del Piano M (2007) Measurement of Chlamydia pneumoniae bacterial load in peripheral blood mononuclear cells may be helpful to assess the state of chlamydial infection in patients with carotid atherosclerotic disease. Atherosclerosis 195:e224–e230PubMedCrossRefGoogle Scholar