The effects of a fermented rapeseed meal or/and soybean meal additive on the blood lipid profile and immune parameters of piglets and on minerals in their blood and bone

The aim of the study was to assess the effect of the inclusion of dried fermented soybean and/or rapeseed meal in piglet feed on immune parameters, blood lipid parameters, and mineral content in the blood and metacarpal bones. The study was conducted on 150 28-day-old piglets divided into 5 groups. Piglets in the control group (C) received a standard diet with soybean meal. Animals in group FR (group receiving a diet with 8% FRSM) received a diet in which a portion of the soybean meal was replaced with 8% dried fermented rapeseed meal (FRSM). Animals in group FR/FS received a diet in which a portion of the soybean meal was replaced with 6% FRSM and 2% fermented dried soybean meal (FSBM). The piglets in group FS/FR received a diet with 6% FSBM and 2% FRSM. Group FS received a diet in which a portion of the soybean meal was replaced with an 8% share of FSBM. The inclusion of 8% or 6% fermented rapeseed meal (group FR or FR/FS) in the diet of piglets had a beneficial effect on their immune status, as evidenced by the increase in plasma levels of IgG and IgA and the decrease in IL-6 relative to the control group. It also significantly increased the concentrations of minerals, i.e. P, Ca and Zn, in the blood plasma and metacarpal bones of piglets and improved the availability of iron, a key bioelement involved in haemoglobin. The use of 8% or 6% fermented soybean meal in the diet (groups FS and FS/FR) of piglets had a positive effect on blood lipid parameters, reducing CHOL and LDL-cholesterol in the plasma. In conclusion, the fermentation process enables better utilization of rapeseed or soybean meal by pigs. Dried fermented rapeseed meal could partially replace protein components from GMO (genetically modified ogranism) crops (soybean meal) used in diets for pigs.

Absence of αβ T cells accelerates disuse bone loss in male mice after spinal cord injury

Whether T cells promote bone loss following immobilization after spinal cord injury (SCI) remains undetermined. Therefore, wild-type (WT) and T cell-deficient (Tcrb-/- ) male mice underwent sham or contusion SCI to cause hindlimb paralysis. Femurs were isolated and distal and midshaft regions were evaluated by microcomputed tomography scanning. Bone marrow (BM) levels of bone turnover markers, as well as receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG), were measured by ELISA. At 2 weeks post-SCI, immobilization resulted in marked reduction in trabecular fractional bone volume (55%), thickness (40%), connectivity, and cortical thickness only in the Tcrb-/- animals (interaction with P < 0.05). BM analysis revealed lower bone formation (procollagen type 1 intact N-terminal propeptide), higher bone resorption (tartrate-resistant acid phosphatase-5b), and a higher RANKL/OPG ratio in the Tcrb-/- SCI animals. At 5 weeks post-SCI, while both WT and Tcrb-/- paralyzed animals showed deterioration of all indices of bone structure, they were more severe in Tcrb-/- animals. In summary, unlike other skeletal disorders, loss of αβ T cells compromises, rather than preserves, skeletal integrity under conditions of immobilization.

[Inflammation caused by different immune cell subsets is involved in bone destruction of rheumatoid arthritis]

Objective To observe the relationship of rheumatoid arthritis (RA) bone destruction with T cells, regulatory T cells (Tregs), CD19⁺ B cells and immune inflammation. Methods The study enrolled randomly 20 RA patients (RA group) and 20 normal controls (NC group). Bone mineral density was measured by DXEA dual energy X-ray bone densitometer. The serum levels of γ-interferon (IFN-γ) of Th1 cells, interleukin-4 (IL-4) of Th2 cells, IL-17, type I procollagen amino terminal propeptide (PINP), type I collagen carboxy terminal peptide (CTx), receptor activator of NF-κB ligand (RANKL) and osteoprotectin (OPG) were detected by ELISA. T-cell subsets, Tregs, CD19⁺ B cells in peripheral blood were measured by flow cytometry. Spearman method was used to analyze the correlations of T cells, Treg and CD19⁺ B cells with bone density and Th1 and Th2 cytokines. Results The bone mineral density T value of the RA group was lower than that of the NC group. The bone mineral density T value of the double forearm was lower than that of the lumbar spine in the RA group. Compared with the NC group, the expression of IFN-γ, IL-17, Th1/Th2 cells, CTx, RANKL increased, and IL-4, PINP decreased in the RA group. Compared with the NC group, the expression of CD4⁺/CD8⁺ T cells, CD19⁺ B cells increased, and CD8⁺ T cells, CD4⁺CD25⁺ Tregs decreased in the RA group. Correlation analysis showed that CD8⁺ T cells were positively correlated with Th1/Th2 cells and IL-17, while CD4⁺ CD25⁺ Tregs were negatively correlated with CTx, and CD19⁺ B cells were negatively correlated with OPG in RA. Conclusion T cells and CD19⁺ B cells may participate in the process of bone destruction in RA by mediating inflammatory immunity.

CD4 T cell count is inversely associated with lumbar spine bone mass in HIV-infected men under the age of 50 years

HIV-infected men under the age of 50 years had a lower bone mass compared to that of HIV-uninfected men. Lower CD4 T cell counts, independent of whether antiretroviral therapy (ART) was used, were associated with lower BMD. HIV-infected patients with low CD4 T cell counts may need follow-up and intervention regarding bone health, including younger patients.

INTRODUCTION

HIV-infected patients have a low bone mineral density (BMD) owing to multifactorial interaction between common osteoporosis risk factors and HIV-related factors, including chronic inflammation and ART. Although HIV infection and ART might affect bone metabolism, little data is available for patients aged under 50 years. We aimed to investigate the association of HIV infection-induced low CD4 T cell counts and ART with BMD in men aged under 50 years.

METHODS

We performed an age- and body mass index-matched case-control study. BMD values of HIV-infected and HIV-uninfected men (< 50 years) were compared, and HIV-infected men were stratified by CD4 T cell counts and ART use.

RESULTS

After adjusting confounders, HIV-infected men with CD4 T cell counts ≥ 500 cells/μL (n = 28) and < 500 cells/μL (n = 139) had lower BMD at the femoral neck (FN, p < 0.001) and total hip (TH, p < 0.001) than HIV-uninfected men (n = 167). HIV-infected men with CD4 T cell counts < 500/μL had lower BMD at the lumbar spine (LS, p = 0.034) than those with counts of ≥ 500 cells/μL, but not at FN and TH. The CD4 T cell count (γ = 0.169, p = 0.031) was positively correlated with BMD at LS. There was no significant difference in the BMD (p = 0.499-> 0.999) between the ART-naïve (n = 75) and ART-user group (n = 92).

CONCLUSIONS

Despite their relatively younger age, HIV-infected men had a lower BMD than HIV-uninfected men. Lower CD4 T cell counts, irrespective of ART, might result in lower bone mass.

Anti-citrullinated protein antibodies are associated with osteopenia but not with pain at diagnosis of rheumatoid arthritis: data from the BARFOT cohort

BACKGROUND

Anti-citrullinated protein antibodies (ACPA) have been suggested to have a potential role in both bone loss and pain in rheumatoid arthritis (RA), based on studies in vitro and in animal models. Here we addressed if anti-cyclic citrullinated (anti-CCP) antibodies were associated with osteopenia or pain in patients with RA, at the time for diagnosis.

METHODS

Baseline data from the BARFOT (Better Anti-Rheumatic PharmacOTherapy) cohort, which consists of patients with RA with a disease duration of 1 year or less, were analyzed. To be included, they should have been assessed by anti-CCP, dual-energy X-ray absorptiometry (DEXA) of lumbar spine and hip, and/or digital X-ray radiogrammetry (DXR) of the metacarpal bones. Osteopenia was defined as a z-score < - 1 SD. Pain VAS > 40 mm, was defined as patient unacceptable pain. Multiple logistic regression analyses were performed to assess whether anti-CCP was independently associated with osteopenia or unacceptable pain.

RESULTS

Of the 657 patients, 65% were women, 58% were anti-CCP positive, 37% had osteopenia in the lumbar spine, and 29% had osteopenia in the hip. Sixty-one percent had unacceptable pain at diagnosis. Patients positive for anti-CCP had significantly more frequently osteopenia in the femoral neck and Ward's triangle compared with anti-CCP-negative patients (p = 0.016 and 0.003, respectively). This difference was found in men at any anti-CCP titer, but in women, osteopenia in these hip locations was found only in those with high anti-CCP titers (> 500 IU/ml). Anti-CCP was not associated with osteopenia in the lumbar spine or the metacarpal bones. In multiple logistic regression analyses, anti-CCP was independently associated with osteopenia in the femoral neck and/or Ward's triangle but not with unacceptable pain. Instead, inflammatory variables were independently associated with unacceptable pain.

CONCLUSION

These data show that in patients with early RA, anti-CCP positivity was independently associated with osteopenia in the femoral neck and/or Ward, but not in the lumbar spine. In our patients, we could not confirm a recently suggested association between anti-CCP antibodies and pain. Further studies are necessary to explore the possible clinical relevance of interactions between ACPA, bone, and pain found in vitro and in animal models.

Bone Disease in Connective Tissue Disease/Systemic Lupus Erythematosus

This article reviews recent advances in the research of the mechanisms of bone loss, as well as clinical features, economic impact and therapeutic implications of osteoporosis and fractures in patients with systemic lupus erythematosus (SLE) as an illustration of bone disease in a complex systemic autoimmune connective tissue disease. Recent studies demonstrated an increased incidence of osteoporosis and peripheral and vertebral fractures in patients with SLE. The aetiology of bone loss in SLE is multifactorial, including clinical osteoporosis risk factors, systemic inflammation, serological factors, metabolic factors, hormonal factors, possibly genetic factors and medication-induced adverse effects. The incidence of symptomatic fractures in patients with SLE is increased 1.2-4.7-fold and age, disease duration, glucocorticoid use, previous cyclophosphamide use, seizures and a prior cerebrovascular event have been identified as important risk factors. Moreover, a high prevalence of morphometric vertebral fractures was demonstrated, while one in three of these patients has normal bone density, which finding points to the multifactorial aetiology of fractures in SLE. The clinical consequences and economic burden of osteoporosis and fractures as glucocorticoid treatment-related adverse events and the high frequency of glucocorticoid therapy underline the importance of reducing glucocorticoid treatment and prescribing steroid-sparing agents. No data on fall risk and its determinants and the relationship with the occurrence of fractures in patients with SLE are currently available. Fall risk might be increased in lupus patients for several reasons. In addition, the recently reported high prevalence (20%) of frailty in SLE patients may contribute to the increased fracture incidence. Therefore, the relationships between fall risk, frailty and fracture occurrence in SLE might be interesting subjects for future studies.

Gut Microbiota, Immune System, and Bone

The gut microbiota (GM) is the whole of commensal, symbiotic, and pathogenic microorganisms living in our intestine. The GM-host interactions contribute to the maturation of the host immune system, modulating its systemic response. It is well documented that GM can interact with non-enteral cells such as immune cells, dendritic cells, and hepatocytes, producing molecules such as short-chain fatty acids, indole derivatives, polyamines, and secondary bile acid. The receptors for some of these molecules are expressed on immune cells, and modulate the differentiation of T effector and regulatory cells: this is the reason why dysbiosis is correlated with several autoimmune, metabolic, and neurodegenerative diseases. Due to the close interplay between immune and bone cells, GM has a central role in maintaining bone health and influences bone turnover and density. GM can improve bone health also increasing calcium absorption and modulating the production of gut serotonin, a molecule that interacts with bone cells and has been suggested to act as a bone mass regulator. Thus, GM manipulation by consumption of antibiotics, changes in dietary habits, and the use of pre- and probiotics may affect bone health. This review summarizes evidences on the influence of GM on immune system and on bone turnover and density and how GM manipulation may influence bone health.

Correlation study between osteoporosis and hematopoiesis in the context of adjuvant chemotherapy for breast cancer

This retrospective study attempts to establish if a correlation exists between osteoporosis and hematopoiesis before and after adjuvant chemotherapy in the context of non-metastatic breast cancer. Osteoporosis is interpreted both as a direct marker of osteoblastic decline and as an indirect marker of increased bone marrow adiposity within the hematopoietic microenvironment. Patients from the “Centre du Sein” at CHUV (Centre Hospitalier Universitaire Vaudois) undergoing adjuvant chemotherapy were included in this study. Evolution of blood counts was studied in correlation with the osteoporosis status. Toxicity of chemotherapy was coded according to published probability of febrile neutropenia. One hundred forty-three women were included: mean age 52.1 ± 12.5 years, mean BMI (body mass index) 24.4 ± 4.1. BMD (bone mineral density) scored osteoporotic in 32% and osteopenic in 45%. Prior to chemotherapy, BMD was positively correlated with neutrophil (p < 0.001) and thrombocyte (p = 0.01) count; TBS (trabecular bone score) was not correlated with blood count. After the first cycle of chemotherapy, an increase of one point in TBS correlated with a decrease of 57% on the time to reach leucocyte nadir (p = 0.004). There was a positive correlation between BMD and risk of infection (p < 0.001). Our data demonstrates an association between osteoporosis and lower blood counts in a younger cohort than previously published, extending it for the first time to neutrophil counts in females. Our results suggest that the healthier the bone, the earlier the lowest leucocyte count value, prompting further research on this area.

Autoantibodies to Osteoprotegerin are Associated with Low Hip Bone Mineral Density and History of Fractures in Axial Spondyloarthritis: A Cross-Sectional Observational Study

Osteoporosis is a recognised complication of axial spondyloarthritis (axSpA) and is thought to be due to functional impairment and the osteoclast-activating effects of proinflammatory cytokines. The development of autoantibodies to OPG (OPG-Ab) has been associated with severe osteoporosis and increased bone resorption in rheumatoid arthritis. In this study, we screened for the presence of OPG-Ab in axSpA and reviewed their clinical significance. We studied 134 patients, recruited from two centres in the United Kingdom. Their mean age was 47.5 years and 75% were male. Concentrations of OPG-Ab were related to bone mineral density (BMD) and fracture history using linear and logistic regression models adjusting for age, gender, disease duration and activity, body mass index and bisphosphonate use. We detected OPG-Ab in 11/134 patients (8.2%). Femoral neck and total hip BMD were significantly reduced in OPG-Ab positive patients (0.827 vs. 0.967 g/cm², p = 0.008 and 0.868 vs. 1.028 g/cm², p = 0.002, respectively). Regression analysis showed that the presence of OPG-Ab was independently associated with total hip osteopenia (OR_adj 24.2; 95% CI 2.57, 228) and history of fractures (OR_adj 10.5; 95% CI 2.07, 53.3). OPG-Ab concentration was associated with total hip BMD in g/cm² (ß = -1.15; 95% CI -0.25, -0.04). There were no associations between OPG-Ab concentration and bone turnover markers, but free sRANKL concentrations were lower in OPG-Ab-positive patients (median 0.04 vs. 0.11 pmol/L, p = 0.050). We conclude that OPG-Ab are associated with hip BMD and fractures in axSpA suggesting that they may contribute to the pathogenesis of bone loss in some patients with this condition.

Targeting macrophages for cancer therapy disrupts bone homeostasis and impairs bone marrow erythropoiesis in mice bearing Lewis lung carcinoma tumors

Macrophages are represented in all tissues by phenotypically distinct resident populations that show great functional diversity. Macrophages generally play a protumoral role, and they are attractive targets for cancer therapy. In this study, we found that CD169⁺ macrophages depletion inhibited the growth of established Lewis lung carcinoma tumors in mice. Benefits must be weighed against potential adverse effects in cancer therapy. Here, we investigated the adverse effects of CD169⁺ macrophages depletion on bone and bone marrow in mice bearing Lewis lung carcinoma tumors. Our studies showed that depletion of CD169⁺ macrophages in LLC tumor-bearing mice disrupted bone homeostasis, including bone weight loss and bone mineral density decrease. Further studies revealed that bone marrow erythropoiesis was severely impaired after depletion of CD169⁺ macrophages in LLC tumor-bearing mice. Our findings suggest that depletion of macrophages for cancer therapy may be associated with potential adverse effects that need to be recognized, prevented, and optimally managed.

A translational approach from an animal model identifies CD80 as a candidate gene for the study of bone phenotypes in postmenopausal women

This study represented a translational study that first compared gene expression of B cells of BM from ovariectomized and control mice, and then analyzed some of the differentially expressed genes in women. Results showed novel genetic associations with bone phenotypes and points to the CD80 gene as relevant in postmenopausal bone loss.

INTRODUCTION

Osteoporosis is a multifactorial disease with a strong genetic component. However, to date, research into osteoporosis has only been able to explain a small part of its heritability. Moreover, several components of the immune system are involved in the regulation of bone metabolism. Among them, B cells occupy a prominent place.

METHODS

The study consisted of two stages. In the first, gene expression in bone marrow B cells is compared between ovariectomized and SHAM control mice using microarrays. In the second, we studied the association of polymorphisms in some differentially expressed genes (DEG) in a cohort of postmenopausal women.

RESULTS

The present study has found 2791 DEG (false discovery rate (FDR) <5%), of which 1569 genes were upregulated (56.2%) and 1122 genes (43.8%) were downregulated. Among the most altered pathways were inflammation, interleukin signaling, B cell activation, TGF-beta signaling, oxidative stress response, and Wnt-signaling. Sixteen DEG were validated by MALDI-TOF mass spectrometry or qPCR. The translational stage of the study genotyped nine single nucleotide polymorphisms (SNPs) of DEG or related and detected association with bone mineral density (BMD) (nominal P values), while adjusting for confounders, for SNPs in the CD80, CD86, and HDAC5 genes. In the logistic regression analysis adjusted for confounders, in addition to the SNPs in the aforementioned genes, the SNPs in the MMP9 and SOX4 genes were associated with an increased risk of osteoporosis. Finally, two SNPs (in the CD80 and SOX6 genes) were associated with an increased risk of bone fragility fracture (FF). However, after Bonferroni correction for multiple testing, only the association between CD80 with BMD and risk of osteoporosis remained significant.

CONCLUSION

These results show that the use of animal models is an appropriate method for identifying genes associated with human bone phenotypes.

Functional block of IL-17 cytokine promotes bone healing by augmenting FOXO1 and ATF4 activity in cortical bone defect model

We determine the effect of interleukin (IL)-17 neutralizing antibody on new bone regeneration. Anti-IL-17 antibody promoted new bone regeneration in cortical bone defect model by augmenting FOXO1 and ATF4 activity thereby decreasing oxidative stress. Our study demonstrates the bone healing and regeneration potential of neutralizing IL-17antibody in osteoporotic fractures.

INTRODUCTION

The immune system plays important role in the fracture healing process. However, fracture healing is prolonged in disorders associated with systemic inflammation. Fracture healing is decelerated in osteoporosis, condition linked with systemic inflammation. Bone regeneration therapies like recombinant human BMP2 are associated with serious side effects. Studies have been carried out where agents like denosumab and infliximab enhance bone regeneration in osteoporotic conditions. Our previous studies show the osteoprotective and immunoprotective effects of neutralizing IL-17 antibody. Here, we determine the effect of IL-17 neutralizing antibody on new bone regeneration and compare its efficacy with known osteoporotic therapies.

METHODS

For the study, female BALB/c mice were ovariectomized or sham operated and left for a month followed by a 0.6-mm drill-hole injury in femur mid-diaphysis. The treatment was commenced next day onwards with anti-IL-17, anti-RANKL (Receptor activator of nuclear factor kappa-B ligand), parathyroid hormone (PTH), or alendronate for a period of 3, 10, or 21 days. Animals were then autopsied, and femur bones were dissected out for micro-CT scanning, confocal microscopy, and gene and protein expression studies.

RESULTS

Micro-CT analysis showed that anti-IL-17 antibody promoted bone healing at days 10 and 21, and the healing effect observed was significantly better than Ovx, anti-RANKL antibody, and ALN, and equal to PTH. Anti-IL-17 also enhanced new bone regeneration as assessed by calcein-labeling studies. Additionally, anti-IL-17 therapy enhanced expression of osteogenic markers and decreased oxidative stress at the injury site.

CONCLUSION

Overall, our study demonstrates bone healing and regeneration potential of neutralizing IL-17 antibody in osteoporotic fractures.

Association of Plasma SDF-1 with Bone Mineral Density, Body Composition, and Hip Fractures in Older Adults: The Cardiovascular Health Study

Aging is associated with an increase in circulating inflammatory factors. One, the cytokine stromal cell-derived factor 1 (SDF-1 or CXCL12), is critical to stem cell mobilization, migration, and homing as well as to bone marrow stem cell (BMSC), osteoblast, and osteoclast function. SDF-1 has pleiotropic roles in bone formation and BMSC differentiation into osteoblasts/osteocytes, and in osteoprogenitor cell survival. The objective of this study was to examine the association of plasma SDF-1 in participants in the cardiovascular health study (CHS) with bone mineral density (BMD), body composition, and incident hip fractures. In 1536 CHS participants, SDF-1 plasma levels were significantly associated with increasing age (p < 0.01) and male gender (p = 0.04), but not with race (p = 0.63). In multivariable-adjusted models, higher SDF-1 levels were associated with lower total hip BMD (p = 0.02). However, there was no significant association of SDF-1 with hip fractures (p = 0.53). In summary, circulating plasma levels of SDF-1 are associated with increasing age and independently associated with lower total hip BMD in both men and women. These findings suggest that SDF-1 levels are linked to bone homeostasis.

[THE DEFEAT OF BONE TISSUE IN CHILDREN WITH INFLAMMATORY BOWEL DISEASES]

Article (literature review) is devoted to the actual problem of osteopenia and osteoporosis in children with Crohn's disease and ulcerative colitis

Serum Level of Interleukin-37 and Expression of Its mRNA in Ankylosing Spondylitis Patients: Possible Role in Osteoporosis

Ankylosing spondylitis (AS) is a chronic inflammatory disease of the axial skeleton.Interleukin-37 (IL-37) is a member of IL-1 family cytokines, that downregulate expression of pro-inflammatory cytokines in chronic inflammatory diseases. The aim of the work is to investigate role of IL-37 in AS disease activity and osteoporosis. Twenty-five patients with AS and 25 controls were enrolled into this study. They were subjected to full clinical examination including assessment of disease activity according to the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Serum IL-37 levels and IL-37 mRNA relative concentration were measured by enzyme-linked immunosorbent assay (ELISA)‎ and quantitative reverse transcriptase- polymerase chain reaction (RT-PCR) respectively. Bone mineral density (BMD) was determined using dual energy X-ray absorptiometry (DEXA). Spine radiographs were scored using the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). Mean serum IL-37 level was significantly higher in AS patients compared with the ‎controls (P < 0.001) and significantly elevated in AS ‎patients with osteoporosis (P < 0.05). IL-37 mRNA gene expression showed a significant increase expression in active AS patient (25 folds) as well as in inactive patient (12 folds) as compared to ‎controls‎.‎ In conclusion, serum IL-37 and its mRNA expression is increased in ‎AS patients with special ‎consideration in patient with Osteoporosis and ‎correlates with disease activity and ‎BMD which indicate that IL-37 may provide a novel research ‎target for pathogenesis and therapy of AS.‎.

Role of T-cell reconstitution in HIV-1 antiretroviral therapy-induced bone loss

HIV infection causes bone loss. We previously reported that immunosuppression-mediated B-cell production of receptor activator of NF-κB ligand (RANKL) coupled with decline in osteoprotegerin correlate with decreased bone mineral density (BMD) in untreated HIV infection. Paradoxically, antiretroviral therapy (ART) worsens bone loss although existing data suggest that such loss is largely independent of specific antiretroviral regimen. This led us to hypothesize that skeletal deterioration following HIV disease reversal with ART may be related to T-cell repopulation and/or immune reconstitution. Here we transplant T cells into immunocompromised mice to mimic ART-induced T-cell expansion. T-cell reconstitution elicits RANKL and TNFα production by B cells and/or T cells, accompanied by enhanced bone resorption and BMD loss. Reconstitution of TNFα- or RANKL-null T-cells and pharmacological TNFα antagonist all protect cortical, but not trabecular bone, revealing complex effects of T-cell reconstitution on bone turnover. These findings suggest T-cell repopulation and/or immune reconstitution as putative mechanisms for bone loss following ART initiation.

Bone-immune cell crosstalk: bone diseases

Bone diseases are associated with great morbidity; thus, the understanding of the mechanisms leading to their development represents a great challenge to improve bone health. Recent reports suggest that a large number of molecules produced by immune cells affect bone cell activity. However, the mechanisms are incompletely understood. This review aims to shed new lights into the mechanisms of bone diseases involving immune cells. In particular, we focused our attention on the major pathogenic mechanism underlying periodontal disease, psoriatic arthritis, postmenopausal osteoporosis, glucocorticoid-induced osteoporosis, metastatic solid tumors, and multiple myeloma.

Effects of the gut microbiota on bone mass

The gut microbiota (GM), the commensal bacteria living in our intestine, performs numerous useful functions, including modulating host metabolism and immune status. Recent studies demonstrate that the GM is also a regulator of bone mass and it is proposed that the effect of the GM on bone mass is mediated via effects on the immune system, which in turn regulates osteoclastogenesis. Under normal conditions, the skeleton is constantly remodeled by bone-forming osteoblasts (OBs) and bone-resorbing osteoclasts (OCLs), and imbalances in this process may lead to osteoporosis. Here we review current knowledge on the possible role for the GM in the regulation of bone metabolism and propose that the GM might be a novel therapeutic target for osteoporosis and fracture prevention.

[Anti-sclerostin antibody : its bone formation effect and therapeutic potential for osteoporosis]

In a rare accident of nature, some families have been found to have dense and strong bones due to a recessive loss of function mutation in the SOST gene that encodes for sclerostin, a protein expressed by osteocytes that downregulates osteoblastic bone formation. Knowledge of this molecule and its actions led rather quickly to the development of anti-sclerostin antibodies that lead to marked increases in bone mass in both animals and human subjects. Blocking sclerostin action with anti-sclerostin antibodies is a promising new therapeutic approach to osteoanabolic therapy of osteoporosis.

[Anti-Dickkopf1 (Dkk1) antibody as a bone anabolic agent for the treatment of osteoporosis]

Wnt/β-catenin signaling pathway plays an important role in bone metabolism. This signal is subject to strict regulation, involving endogenous soluble inhibitors. Dkk1 is a member of family of secreted protein which functions in head induction during Xenopus embryogenesis. Dkk1 forms a ternary complex with LRP5/6 and Kremen, resulting in suppression of Wnt signaling and decreased bone formation. Heterozygous knockout mice of Dkk1 show high bone mass, while transgenic mice overexpressing Dkk1 exhibit low bone mass phenotype. Anti-Dkk1 monoclonal antibody has been shown to accelerate bone formation and increase bone mineral density in various animal models and is under development as a bone-anabolic agent.

Postmenopausal osteoporosis: the role of immune system cells

In the last years, new evidences of the relationship between immune system and bone have been accumulated both in animal models and in humans affected by bone disease, such as rheumatoid arthritis, bone metastasis, periodontitis, and osteoporosis. Osteoporosis is characterized by low bone mass and microarchitectural deterioration of bone tissue with a subsequent increase in bone fragility and susceptibility to fractures. The combined effects of estrogen deprivation and raising of FSH production occurring in menopause cause a marked stimulation of bone resorption and a rapid bone loss which is central for the onset of postmenopausal osteoporosis. This review focuses on the role of immune system in postmenopausal osteoporosis and on therapeutic strategies targeting osteoimmunology pathways.

Increased bone formation and bone mass induced by sclerostin antibody is not affected by pretreatment or cotreatment with alendronate in osteopenic, ovariectomized rats

Clinical studies have revealed a blunting of the bone anabolic effects of parathyroid hormone treatment in osteoporotic patients in the setting of pre- or cotreatment with the antiresorptive agent alendronate (ALN). Sclerostin monoclonal antibody (Scl-Ab) is currently under clinical investigation as a new potential anabolic therapy for postmenopausal osteoporosis. The purpose of these experiments was to examine the influence of pretreatment or cotreatment with ALN on the bone anabolic actions of Scl-Ab in ovariectomized (OVX) rats. Ten-month-old osteopenic OVX rats were treated with ALN or vehicle for 6 wk, before the start of Scl-Ab treatment. ALN-pretreated OVX rats were switched to Scl-Ab alone or to a combination of ALN and Scl-Ab for another 6 wk. Vehicle-pretreated OVX rats were switched to Scl-Ab or continued on vehicle to serve as controls. Scl-Ab treatment increased areal bone mineral density, volumetric bone mineral density, trabecular and cortical bone mass, and bone strength similarly in OVX rats pretreated with ALN or vehicle. Serum osteocalcin and bone formation rate on trabecular, endocortical, and periosteal surfaces responded similarly to Scl-Ab in ALN or vehicle-pretreated OVX rats. Furthermore, cotreatment with ALN did not have significant effects on the increased bone formation, bone mass, and bone strength induced by Scl-Ab in the OVX rats that were pretreated with ALN. These results indicate that the increases in bone formation, bone mass, and bone strength with Scl-Ab treatment were not affected by pre- or cotreatment with ALN in OVX rats with established osteopenia.

Preservation of femoral bone thickness in middle age predicts survival in genetically heterogeneous mice

To see whether age-related changes in bone could predict subsequent lifespan, we measured multiple aspects of femur size and shape at 4, 15, and 24 months of age in genetically heterogeneous mice. Mice whose cortical bone became thicker from 4 to 15 months, associated with preservation of the endosteal perimeter, survived longer than mice whose endosteal cavity expanded, at the expense of cortical bone, over this age range. Femur size at age 4 months was also associated with a difference in life expectancy: mice with larger bones (measured by length, cortical thickness, or periosteal perimeter) had shorter lifespans. Femur length, midlife change in cortical bone thickness, and midlife values of CD8 T memory cells each added significant power for longevity prediction. Mice in the upper half of the population for each of these three endpoints lived, on average, 103 days (12%) longer than mice with the opposite characteristics. Thus, measures of young adult bone dimensions, changes as a result of bone remodeling in middle age, and immunological maturation provide partially independent indices of aging processes that together help to determine lifespan in genetically heterogeneous mice.

Transplantation osteoporosis

Transplantation provides a valuable, often life-saving, treatment for end-stage failure of many organs, including the heart, kidneys, liver, pancreas and lungs. It is also an important therapeutic option in diseases of the bone marrow and the immune system. Despite the undoubted benefits for transplant patients, it is associated with an increased risk of many complications. The potential causes include: poor general health of the patient, heavy burden of the surgery itself and the need for the long-term use of immunosuppression. In addition, the patients are also on numerous other medications, e.g. anti-coagulants, diuretics. Osteoporosis and high risk of fractures have emerged as frequent and devastating complications of the transplantation process. This article provides a review of the current literature on osteoporosis after transplantation, and the treatment options for this serious illness.

Bone density and hyperlipidemia: the T-lymphocyte connection

Osteoporosis, which contributes to morbidity and mortality, often coexists with cardiovascular disease, especially atherosclerosis. We have reported recently that in vitro exposure of human T-lymphocytes to oxidized lipids induced expression of a key osteoclastogenic cytokine, receptor activator of NF-κB ligand (RANKL). Our previous studies have shown that mice fed an atherogenic high-fat diet developed osteopenia and that bone marrow preosteoclasts from these hyperlipidemic mice have increased osteoclastic potential. To investigate the role of T-lymphocytes in the diet-induced bone loss, C57BL/6 mice were fed either chow or a high-fat diet, and bone parameters and T-lymphocyte activation were assessed at 6 and 11 months. Consistent with our previous findings, peripheral quantitative computed tomographic (pQCT) analysis showed that mice in the high-fat group had lower bone mineral content than mice in the chow group. Furthermore, histomorphometric analysis showed decreased structural parameters in the high-fat group. Coculture studies showed that bone marrow cells isolated from the high-fat group, which contained increased levels of activated memory T-lymphocytes compared with bone marrow cells from the chow mice, supported osteoclastic differentiation of RAW 264.7 cells. Additionally, RANKL expression was upregulated significantly in the T-lymphocytes isolated from the bone marrow of the high-fat group. Splenic T-lymphocytes isolated from the high-fat group also had increased expression of transcripts for the receptor for oxidized lipids (LOX-1) as well as for inflammatory and osteoclastogenic cytokines, including RANKL, interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), IL-1β, and interferon γ (IFN-γ). Together these findings suggest that T-lymphocytes play a key role in the osteoclastogenesis induced by a high-fat diet and may contribute to the bone loss associated with diet-induced osteopenia.

Osteoporosis associated with neutralizing autoantibodies against osteoprotegerin

Autoantibodies against osteoprotegerin, which block the inhibitory effect of osteoprotegerin on signaling by the receptor activator of nuclear factor (NF)-kappaB (RANK), were identified in a man with celiac disease who presented with severe osteoporosis and high bone turnover. The osteoporosis did not respond to the treatment of his celiac disease but was completely reversed by bisphosphonate therapy. Autoantibodies against osteoprotegerin were detected in three additional patients with celiac disease. Such autoantibodies may be associated with the development of high-turnover osteoporosis, but whether autoantibodies against osteoprotegerin commonly contribute to the pathogenesis of osteoporosis in patients with celiac disease remains to be determined.

Efficacy and safety of denosumab in postmenopausal women with osteopenia or osteoporosis: a systematic review and a meta-analysis

Receptor activator of nuclear factor-kappaB ligand (RANKL) is a cytokine essential for osteoclast differentiation, activation, and survival. Denosumab, a human monoclonal antibody against RANKL, constitutes a promising antiresorptive agent for osteoporosis. We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), and other trial registries through January 2009. We selected randomized controlled trials (RCTs) of denosumab in women with low bone mass that described the changes on bone markers and bone mineral density (BMD) as well as the adverse events including fracture risk. We analyzed data from nine RCTs involving 10 329 participants. Although denosumab universally decreased bone markers and increased lumbar and hip BMD, the efficacy evaluation based on percentage (%) mean change from the baseline was not possible due to missing data. Denosumab was not associated with a significant reduction in fracture risk [OR (95% CI) 0.74 (0.33 to 1.64), p=0.45]. Increased risk of serious adverse events [OR (95% CI) 1.83 (1.10 to 3.04), p=0.02] and serious infections [OR (95% CI) 4.45 (1.15 to 17.14), p=0.03] were evident. In conclusion, although effective as an antiresorptive agent, denosumab has not yet proved its efficacy on fracture risk reduction while increased infection risk questions its safety.

Two-year treatment with denosumab (AMG 162) in a randomized phase 2 study of postmenopausal women with low BMD

Denosumab is a monoclonal antibody to RANKL. In this randomized, placebo-controlled study of 412 postmenopausal women with low BMD, subcutaneous denosumab given every 3 or 6 mo was well tolerated, increased BMD, and decreased bone resorption markers for up to 24 mo. Continued study of denosumab is warranted in the treatment of low BMD in postmenopausal women.

INTRODUCTION

Denosumab is a fully human monoclonal antibody that inhibits RANKL, a key mediator of osteoclastogenesis and bone remodeling. This prespecified exploratory analysis evaluated the efficacy and safety of denosumab through 24 mo in the treatment of postmenopausal women with low BMD.

MATERIALS AND METHODS

Four hundred twelve postmenopausal women with lumbar spine BMD T-scores of -1.8 to -4.0 or femoral neck/total hip T-scores of -1.8 to -3.5 were randomly assigned to receive double-blind, subcutaneous injections of placebo; denosumab 6, 14, or 30 mg every 3 mo; denosumab 14, 60, 100, or 210 mg every 6 mo; or open-label oral alendronate 70 mg once weekly. Outcome measures included BMD at the lumbar spine, total hip, distal one-third radius, and total body; bone turnover markers; and safety.

RESULTS

Denosumab increased BMD at all measured skeletal sites and decreased concentrations of bone turnover markers compared with placebo at 24 mo. At the lumbar spine, BMD increases with denosumab ranged from 4.13% to 8.89%. BMD changes with denosumab 30 mg every 3 mo and > or =60 mg every 6 mo were similar to, or in some cases greater than, with alendronate. The incidence of adverse events was similar in the placebo, denosumab, and alendronate treatment groups. Exposure-adjusted adverse events over 2 yr of treatment were similar to those reported during the first year of treatment.

CONCLUSIONS

In these postmenopausal women with low BMD, treatment with denosumab for 2 yr was associated with sustained increases in BMD and reductions in bone resorption markers compared with placebo.

Prevalence of IgA-antiendomysial antibody in a patient cohort with idiopathic low bone mineral density

AIM: To investigate the frequency of serum IgA-antiendomysial antibody positivity in patients with low bone mineral density and to assess the risk group for screening of celiac disease.

METHODS: One hundred and thirty-five patients (14 male, 121 female) with idiopathic low bone mineral density were evaluated. The median age was 57.2 years (24-81). Antiendomysial antibody was determined by the immunofluorescence method using a commercial kit (INOVA Diagnostics Inc., CA, USA), which employs a 5 μm thin cryostat section of monkey esophagus as a substrate.

RESULTS: Of the 135 patients evaluated, 13 were found to have positive IgA antiendomysial antibody test (9.6%) response. None of the patients had IgA deficiency. Endoscopic appearance and histological examination were normal in all of these patients. Seropositive patients had significantly lower age (48.9 ± 4.3 vs 59.2 ± 6.2, P < 0.05), higher ratio of male gender (61.5% vs 4.9%, P < 0.01) and pre-menopausal status (8.7% vs 1.3%, P < 0.01). Lumbar spine and femoral neck z-scores, but not t-scores were significantly lower in seropositive patients. Seropositive patients had lower serum 25 (OH) vitamin D, calcium and higher serum parathormone levels than seronegative patients.

CONCLUSION: The screening of celiac disease in idiopathic osteoporosis should be restricted to patients without classical risk factors (younger, pre-menopausal, male gender) for osteoporosis. Bone mineral density measurements using z-scores should be considered for identifying risk groups for celiac disease.

Reduced cortical bone mass in mice with inactivation of interleukin-4 and interleukin-13

The aim of the present study was to study the in vivo role of IL-4 and IL-13 on bone metabolism. The skeletal phenotypes of male and female IL-13(-/-) (n = 7+7), IL-4(-/-)IL-13(-/-) (n = 7+7), and WT (n = 7+7) mice were compared. Analysis was made at 6 weeks of age (juvenile) by pQCT, and at 20 weeks of age (adult) by pQCT, biomechanical testing, and by S-IGF-1 and S-Osteocalcin measurements. The skeletal phenotype was affected only in adult male IL-4(-/-)IL-13(-/-) mice. These animals displayed a reduction in cortical bone mineral content (BMC) of both the tibia and the femur, as measured by mid-diaphyseal pQCT scans, compared with WT mice (tibia -8.2%; femur -8.5%; p < 0.01). This reduction in cortical BMC was due to a decreased cross-sectional area as a result of a reduced cortical thickness. The mechanical strength of the cortical bone, tested by three-point-bending at the mid-diaphyseal region of the femurs, demonstrated a significant reduction of displacement at failure (-11.4%), maximal load at failure (-10.6%), and total energy until failure (-29.4%). S-IGF-1 and S-Osteocalcin levels as well as trabecular bone mineral density (tvBMD) were unaffected in adult male IL-4(-/-)IL-13(-/-) mice. IL-4(-/-)IL-13(-/-) male mice show adult onset reduction of cortical bone mass and strength, indicating that the two anti-inflammatory Th(2) cytokines IL-4 and IL-13 are involved in the regulation of bone remodeling.

Inflammation is the main determinant of low bone mineral density in pediatric inflammatory bowel disease

AIMS

To assess bone mineral density (BMD) in children with Crohn's disease (CD) and ulcerative colitis (UC) and to investigate the role of inflammation and steroids on BMD.

METHODS

Lumbar spine areal BMD was measured by DXA, and volumetric BMD was then estimated (BMAD); inflammatory cytokines (TNF-alpha, IL-6, IL-10, and IL-12) were dosed in peripheral blood; and cumulative and daily doses of steroids were calculated. Therapy with infliximab (IFX) was considered for CD patients.

RESULTS

Fifty-six patients with IBD (35 CD, 21 UC) were studied. An inverse correlation was found between BMAD and IL-6 in patients with UC (r = -0.65); no correlation was found between BMAD and serum levels of TNF-alpha, IL-10, and IL-12 in all patients. Disease activity indexes use inversely correlated with BMAD (r = -0.62 in patients with CD and r = -0.64 in patients with UC). Cumulative dose of corticosteroids and duration of therapy did not correlate with BMAD. The 10 patients with CD who were treated with IFX had higher BMAD (-1 +/- 0.8) than those never treated with IFX (-1.8 +/- 0.8). Mean Pediatric Crohn's Disease Activity Index and body mass index in patients with CD (R(2) = 0.48) and IL-6 level in patients with UC (R(2) = 0.43) were found to be independent and significant predictors of BMAD.

CONCLUSIONS

In children with IBD, inflammation is an important determinant of bone loss, as shown by the correlation of BMAD with serum IL-6 and with disease activity indexes as well as by the beneficial effect of IFX on bone density. Corticosteroids seem to be a less important variable in pediatric IBD-related BMD reduction than previously believed.

B cells and T cells are critical for the preservation of bone homeostasis and attainment of peak bone mass in vivo

Bone homeostasis is regulated by a delicate balance between osteoblastic bone formation and osteoclastic bone resorption. Osteoclastogenesis is controlled by the ratio of receptor activator of NF-kappaB ligand (RANKL) relative to its decoy receptor, osteoprotegerin (OPG). The source of OPG has historically been attributed to osteoblasts (OBs). While activated lymphocytes play established roles in pathological bone destruction, no role for lymphocytes in basal bone homeostasis in vivo has been described. Using immunomagnetic isolation of bone marrow (BM) B cells and B-cell precursor populations and quantitation of their OPG production by enzyme-linked immunosorbent assay (ELISA) and real-time reverse transcriptase-polymerase chain reaction (RT-PCR), cells of the B lineage were found to be responsible for 64% of total BM OPG production, with 45% derived from mature B cells. Consistently B-cell knockout (KO) mice were found to be osteoporotic and deficient in BM OPG, phenomena rescued by B-cell reconstitution. Furthermore, T cells, through CD40 ligand (CD40L) to CD40 costimulation, promote OPG production by B cells in vivo. Consequently, T-cell-deficient nude mice, CD40 KO mice, and CD40L KO mice display osteoporosis and diminished BM OPG production. Our data suggest that lymphocytes are essential stabilizers of basal bone turnover and critical regulators of peak bone mass in vivo.

[Increase in T-cell level in the peripheral blood of women with fractures in anamnesis during postmenopause period]

44 postmenopausal patients (45-76 years of old) have been observed. Interrelationship between composition and functional activity of peripheral blood cells, TNF-alpha level in the serum and bone density in postmenopausal women has been analyzed. It was established that the increase in neutrophil activity in women with osteoporosis, the high level of immune complexes are accompanied by the high level of IgG and autoantibodies to DNA. These results allow suggesting the presence of chronic inflammatory or immune processes taken place in postmenopausal women with osteoporosis. Increase in CD3+ cells percent was established in women with fracture in anamnesis. Obtained results allow suggesting the possibility that T-cells may play a role in the occurrence of fractures.

Are activated T cells regulators of bone metabolism in children with Crohn disease?

OBJECTIVES

To test the hypothesis that circulating activated T cells may release cytokines that decrease bone turnover in children with Crohn disease.

STUDY DESIGN

Newly diagnosed Crohn disease and healthy controls of similar age were compared for bone age, bone mineral content and density, markers of bone remodeling, and serum concentration and in vitro T-cell production of receptor activator of nuclear factor kappaB ligand (RANKL), interferon (INF)-gamma, and osteoprotegerin (OPG).

RESULTS

Newly diagnosed children with Crohn disease (n=23) had similar bone mineral density (BMD) z-scores and body mass index as the controls (n=40). Biochemical markers of bone remodeling indicated a state of low bone turnover in the Crohn disease patients compared with controls. Serum OPG (pmol/L; mean+/-SD, median) was higher (4.24+/-1.74, 3.98 vs 3.38+/-0.83, 3.41; P<.05), and serum RANKL (pmol/L) was lower in the Crohn disease patients (0.50+/-0.86, 0.28 vs 1.02+/-1.63, 0.49; P<.01), consistent with decreased bone resorption. Activated T cells from Crohn disease patients produced a higher concentration of INF-gamma (ng/microg protein) than those from controls (20.03+/-26.39, 8.70 vs 9.76+/-14.10, 6.17; P<.05).

CONCLUSIONS

The newly diagnosed children with Crohn disease exhibited reduced bone remodeling, possibly due to T-cell INF-gamma and OPG.

Relations between interleukin-1, its receptor antagonist gene polymorphism, and bone mineral density in postmenopausal Korean women

We investigated the relation between polymorphisms in the interleukin-1(IL-1) and IL-1 receptor antagonist (IL-1ra) gene, and bone mineral density (BMD) in postmenopausal Korean women. The IL-1alpha C(-889)T polymorphism, and IL-1beta C(-511)T polymorphism were examined by restriction fragment length polymorphism, and 86-bp variable number tandem repeat polymorphism in the IL-1ra gene was analyzed by the polymerase chain reaction and electrophoresis in 202 postmenopausal Korean women. Serum osteocalcin, and C-telopeptide of type I collagen were measured using a radioimmunoassay and enzyme-linked immunosorbent assay, respectively. BMD at the lumbar spine and proximal femur was measured by dual-energy X-ray absorptiometer. No significant differences in BMD or in serum bone markers levels were noted across the IL-1alpha or IL-1beta genotype. There were no significant differences in the distribution of IL-1alpha or IL-1beta genotype according to the status of bone mass. BMD in women carrying the A2 allele of the IL-1ra gene was significantly lower than those without this allele, and the A2 allele was more frequent in osteoporotic women than in normal women. These data suggest that IL-1ra gene VNTR polymorphism is a genetic factor that may affect BMD in Korean women.

Increased bone fracture prevalence in postmenopausal women suffering from pollen-allergy

INTRODUCTION

Our aim was to investigate whether pollen-allergy can affect bone mass and fractures in postmenopausal women.

METHODS

A total of 125 postmenopausal pollen-allergic women (mean age: 61.26 yr) were split into four groups: (1) treated with neither H1 histamine receptor (H1R) antagonist nor inhaled corticosteroid (n=43); (2) treated only with H1R antagonist (n=53); (3) treated with both H1R antagonist and inhaled corticosteroid (n=17); (4) treated with only inhaled corticosteroid (n=12). Treatment, in the appropriate groups, had occurred for at least 5 years, seasonally. One-hundred non-allergic postmenopausal subjects matched for age, body mass index (BMI), and age at menopause served as controls.

RESULTS

Overweight and obesity (25 kg/m(2) < or =BMI) were common among the allergic women (76%). Allergic patients without treatment had a slightly lower bone density than their non-allergic counterparts. The rate (34.9%) of prevalent low-energy fractures (distal forearm, hip, and clinical vertebral fractures) in untreated allergic patients was almost triple that observed in non-allergic women (13%, chi(2) p=0.003). Bone fracture occurred more often in H1R-only treated patients (30.19%) than in controls (chi(2) p=0.01); however, clinical vertebral or hip fractures developed neither in those treated only with H1R antagonist nor in those who received both H1R antagonist and inhaled corticosteroid. Bone fractures were more frequent among patients with inhaled steroid treatment than among patients with a combined treatment of inhaled steroid and antihistamine (50 versus 29.4%). BMI predicted prevalent fractures at 1.278 (95% CI: 1.047-1.559, p=0.016) for a 1 kg/m(2) increase among untreated allergic patients.

CONCLUSION

In conclusion, we found a high prevalence of low-energy fractures among pollen-allergic postmenopausal women which was associated with obesity. It is possible that the H1R antagonists compensate for both the negative effect of pollen-allergy and the adverse effect of inhaled corticosteroid treatment on bone fracture risk.

Cytokine production by whole blood cells: relationship to interleukin gene polymorphism and bone mass

The aims of this study were to investigate the relationships between the production of interleukin-1 (IL-1), and IL-6 system by whole blood cells, and bone mineral density (BMD), and polymorphisms in IL-1 system and IL-6 gene in postmenopausal Korean women. The production of IL-1alpha, IL-1beta, IL-1 receptor antagonist (IL-1ra), IL-6, and soluble IL-6 receptor (sIL-6r) by lipopolysaccharide-stimulated whole blood cells was measured by ELISA in 110 subjects. Serum osteocalcin, C-telopeptide of type I collagen, and BMD at lumbar spine and proximal femur were measured. IL-1alphaC(-889)T polymorphism, IL-1beta C(-511)T polymorphism, 86-base pair variable number tandem repeat polymorphism in the IL-1ra gene, and IL-6 C(-634)G polymorphism were analyzed. The production of IL-1beta correlated positively with BMD at femoral neck, whereas the production of other ILs did not correlate with BMD at the skeletal sites examined. No significant differences in the production of ILs were observed among normal, osteopenic and osteoporotic postmenopausal women, and among the different IL system polymorphisms groups studied. No correlation between bone turnover markers and the production of ILs was noted. In conclusion IL-1beta may regulate bone metabolism at femoral neck, and the IL system polymorphism do not affect the production of ILs by whole blood cells.

Association and linkage analyses of interleukin-6 gene 634C/G polymorphism and bone phenotypes in Chinese

In this study, we tested the interleukin-6 (IL-6) gene as an important candidate gene for its linkage and association with the variation of bone phenotypes (bone mineral density [BMD] and bone size) in young Chinese female subjects. We genotyped the IL-6 gene at the -634C/G restriction fragment length polymorphism (RFLP) site (ID, RS1800796) in 1263 individuals from 402 Chinese nuclear families, composed of both parents and at least one healthy daughter (mean age +/- SD, 31.4 +/- 5.8 years). Using the daughters' bone phenotypes, we tested total-family association, within-family association (via transmission disequilibrium test, [TDT]), and linkage, between the -634C/G marker and bone phenotypes at the spine and the hip. No significant association or linkage was found for bone size and BMD, although a trend was observed for linkage between the IL-6 gene -634C/G marker and L1-4 spinal BMD (adjusted for age, weight, and height). Our results, together with the findings from other studies, indicate that the IL-6 gene, although important for postmenopausal bone loss, may have a limited impact on peak bone mass variation in a Chinese population.

Interleukin 10-deficient mice develop osteopenia, decreased bone formation, and mechanical fragility of long bones

BACKGROUND & AIMS

Bone loss is a common complication of human inflammatory bowel disease (IBD), but its mechanisms are not understood completely. We investigated bone metabolism in interleukin-10-deficient ( IL-10-/- ) mice, an animal model with IBD features.

METHODS

IL-10-/- male mice (8- and 12-weeks-old) and their age-matched wild-type counterparts (C57BL/6J) were studied. Bone mass of the femur was determined by ashing. Tibial cancellous and cortical bone mass and formation was measured by static and dynamic histomorphometry. Biomechanical strength of the femur was tested. Primary bone marrow stromal cell cultures were used to assess osteoblast generation. Serum levels of 25-OH vitamin D 3, insulin-like growth factor-1 (IGF-1), parathyroid hormone, osteocalcin, and deoxy-pyridinoline cross-links were measured. The presence of colitis was determined histologically, and by IL-12 and interferon-gamma (IFN-gamma) secretion from cultured colonic explants.

RESULTS

Eight- and 12-week-old IL-10-/- mice developed osteopenia of both cancellous and cortical bone, evidenced by lower femoral ash weight, cancellous bone area and surface, trabecular number, and decreased cortical bone area and width. Osteopenia was associated with mechanical fragility, manifested by decreased stiffness and mechanical load at fracture, and was caused by suppressed bone formation, indicated by decreased cancellous double-labeled surface, mineralizing surface, serum osteocalcin level, and mineralized nodule number in bone marrow stromal cell cultures. IL-10-/- mice with colitis had significantly less bone mass compared with IL-10-/- mice without colitis.

CONCLUSIONS

IL-10-/- mice develop the hallmarks of osteoporosis, that is, reduced bone mass, increased mechanical fragility, and suppressed bone formation. The presence of colitis is an important contributor to osteoporosis in IL-10-/- mice.

Bone mineral density in children with familial Mediterranean fever

The aim of this study was to evaluate bone mineral content (BMC), serum and urinary bone turnover parameters in patients with familial Mediterranean fever (FMF), an autosomal recessive disease characterized by recurrent episodes of inflammation of serous membranes. Demographic characteristics and MEFV mutations were defined in 48 children diagnosed with FMF (23 F, 25 M; median age 7.0 years (3.0-10.0)). We evaluated the blood counts, acute-phase proteins and serum and urinary bone turnover parameters during attack-free periods. The BMC and BA (bone area) of vertebrae L1-L4 were measured by DEXA. Thirty-eight age-, sex- and ethnicity-matched healthy children constituted the control group. Mean L1-L4 BMC in Group I (patients with two mutations) and II (patients with no or single mutations) were 15.49+/-5.99 g and 15.68+/-4.89 g, respectively, both significantly lower than the mean L1-L4 BMC of control patients, which was 19.59+/-6.7 g (p<0.05). Mean L1-L4 BMD in Group I, Group II and the control group were 0.466+/-0.066 g/cm(2), 0.487+/-0.085 g/cm(2 )and 0.513+/-0.079 g/cm(2), respectively. Mean z-scores in Group I, Group II and the control group were -1.87+/-0.74, -1.55+/-0.92 and -1.39+/-0.84, respectively. Mean L1-L4 BMD and z-score of Group I were lower than in the control group (p<0.05). ESR and SAA (serum amyloid A) levels were higher in Group I patients: 28.3+/-14.5 mm/h and 350+/-62 mg/l in Group I; and 20.5+/-11.7 mm/h and 190+/-68 mg/l in Group II, respectively. In conclusion, FMF patients had lower BMC, BMD and z-scores than a control group. We suggest that decreased BMD, BMC and z-score in FMF patients may be secondary to subclinical inflammation.

Musculoskeletal manifestations in cystic fibrosis

Although bone and joint manifestations are common in children with cystic fibrosis (CF), they have received little attention in adults. As compared to healthy individuals, bone mineral density is low, even with calcium intakes greater than 1500 mg/d. Nevertheless, calcium and phosphate levels in blood and urine are often normal, and vitamin D levels vary. Short stature with a low body mass index and central hypogonadism are the rule in these patients. Fractures and kyphosis are often reported. CF arthropathy occurs in 2-8.5% of patients. Arthritis develops, and there may be skin eruptions. Non-steroidal antiinflammatory drug therapy is effective. Hypertrophic osteoarthropathy associated with respiratory failure is present in 2-7% of patients. Rheumatoid arthritis, spondyloarthropathies, sarcoidosis, and amyloidosis have been reported in association with CF. Knee pain due to patellofemoral syndrome, quinolone-induced arthropathy, and mechanical back pain have been described. Rheumatoid factor titers are higher than in healthy controls, particularly in patients with episodic arthritis. No data are available on antiperinuclear factor or antikeratin antibody titers. Tests for antinuclear antibody are usually negative. Circulating immune complex levels and antibodies to heat shock proteins may be elevated. Antineutrophil cytoplasmic antibody of the bactericidal/permeability-increasing protein (BPI) or azurocidin (AZ) type has been reported, often in high titers (up to 40%).

[Biochemical and immunological markers of osteoporosis in patients with chronic obstructive pulmonary disease]

A cytokine profile and changes in bone metabolism were studied in 95 patients (30 females and 65 males) with chronic obstructive pulmonary disease (COPD). Subnormal bone density was diagnosed in 78% patients with COPD. Frequency of osteoporosis discovery in emphysema was higher than in chronic obstructive bronchitis and the degree of density loss in bone tissue depended on ventilation disturbance. Intensification of bone resorption in relatively stable osteogenesis was encountered in 73.6% patients and manifested in elevated CrossLaps concentration. A close correlation exists between proinflammatory cytokines, bone density and indices of bone metabolism in COPD. This suggests a significant role of cytokine-mediated mechanisms in pathogenesis of pulmonogenic osteopenia.

Increased bone mass is a part of the generalized lymphoproliferative disorder phenotype in the mouse

We investigated the bone phenotype of mice with generalized lymphoproliferative disorder (gld) due to a defect in the Fas ligand-mediated apoptotic pathway. C57BL/6-gld mice had greater whole body bone mineral density and greater trabecular bone volume than their wild-type controls. gld mice lost 5-fold less trabecular bone and had less osteoclasts on bone surfaces after ovariectomy-induced bone resorption. They also formed more bone in a model of osteogenic regeneration after bone marrow ablation, had less osteoclasts on bone surfaces and less apoptotic osteoblasts. gld and wild-type mice had similar numbers of osteoclasts in bone marrow cultures, but marrow stromal fibroblasts from gld mice formed more alkaline phosphatase-positive colonies. Bone diaphyseal shafts and bone marrow stromal fibroblasts produced more osteoprotegerin mRNA and protein than wild-type mice. These findings provide evidence that the disturbance of the bone system is a part of generalized lymphoproliferative syndrome and indicates the possible role of osteoprotegerin as a regulatory link between the bone and immune system.

Induction of anti-metallothionein antibody and mercury treatment decreases bone mineral density in mice

Mercuric chloride (HgCl2) is an industrial agent with toxic effects on the immune system, kidney, lung, and nervous tissue, but little is known about its effect on bone. Metallothionein (MT) is a cysteine-rich metal-binding protein that exerts cytoprotective effects against heavy metal toxins. It has been reported that the susceptibility of renal and pulmonary toxicity of mercury was markedly enhanced in MT-null mice compared to control mice. However, there is no report about the effects of anti-metallothionein (anti-MT) Ab induction on mercury toxicity. We investigated the effect of anti-MT Ab induction on mercury-induced bone injury. BALB/c mice were injected with MT (10 microg/mouse ic) five times to induce anti-MT Ab and then treated with HgCl2 (1 mg/kg sc) three times per week for 3 weeks. MT immunization plus HgCl2 treatment dramatically decreased bone mineral density (BMD), and the humoral bone formation indices, alkaline phosphatase (ALP) activity and osteocalcin. MT immunization or HgCl2 treatment alone did not affect either BMD or serum ALP activity and osteocalcin levels. MT immunization impeded HgCl2-induced increase of MT expression in the liver and led to an increase of mercury in serum and the liver but a decrease in the kidney. Furthermore, serum titers of IgE and IgG1 were significantly elevated in the MT-immunized plus HgCl2 treatment group compared with those in the HgCl2 treatment group. Similar results were also observed in splenic secretions of IL-4 and IL-10 based on anti-CD3 Ab stimulation. Taken together, our results indicate that anti-MT Ab induction causes mercury-induced bone injury in BALB/c mice and also enhances mercury-related immune disorders.

Association of a single nucleotide variant in the human tumour necrosis factor alpha promoter region with decreased bone mineral density

BACKGROUND

Tumour necrosis factor alpha (TNFalpha) has come to be regarded as a potential osteoporotic factor, because it has stimulatory effects on cells of the osteoclast lineage and has been implicated in the pathogenesis of bone loss associated with oestrogen deficiency. We recently described genetic linkage between the TNFalpha locus and human osteoporosis by sib-pair analysis. However, the molecular mechanism by which this locus regulates bone mineral density (BMD) remains unknown.

AIM

We investigated whether the observed linkage reflects a sequence variation which might affect expression of the TNFalpha gene or alter the function of TNFalpha protein.

SUBJECTS AND METHODS

We examined three single-nucleotide polymorphisms (SNPs) of the TNFalpha gene in a group of 390 postmenopausal Japanese women living in northern Japan. Minor-allele frequencies for the three SNPs (-1031C, -863A and -857T) in this population were 0.16, 0.13 and 0.20, respectively.

RESULTS

Among the three SNPs examined, we observed a significant correlation only between the presence of a T allele at nt -1031 and decreased BMD, by analysis of variance. Among the three genotypic groups at nt -1031, mean BMD values were significantly higher in the T-negative genotype (C/C homozygotes; mean SD = 0.342 +/- 0.052 g cm(-2)), compared with T-positive genotypes (T/T homozygotes, 0.309 +/- 0.062 g cm(-2); p = 0.0253 and T/C heterozygotes, 0.305 +/- 0.062 g cm(-2); p = 0.0164).

CONCLUSIONS

Given the lines of evidence from different genetic studies, we suggest that TNFalpha may play a role in pathogenesis of osteoporosis.

Prevalence of IgA-antiendomysial antibody in asymptomatic low bone mineral density

OBJECTIVE

Celiac disease (CD) is a relatively common gastrointestinal disorder that can be asymptomatic. However, even among asymptomatic patients a long-term reduction in bone mineral density (BMD) is found. Excellent noninvasive screening tests for CD are now available. Studies using older screening techniques have suggested a 10-fold increased prevalence of CD among patients with low BMD, but this has not been confirmed with current testing methodology. We set out to confirm these prevalence estimates using antiendomysial antibody testing.

METHODS

A total of 100 consecutive patients referred to our outpatient endocrinology clinic for evaluation of idiopathic low BMD were studied. In addition to the routine evaluation, patients completed a symptom questionnaire and underwent serological testing for the presence of the IgA antiendomysial antibody (EMA). All patients with a positive EMA underwent small bowel biopsy and permeability studies.

RESULTS

EMA results were available on 96 patients; 78/96 patients were female and the mean age was 57 yr (range 18-86 yr). Seven of 96 (7.3% [95% CI 2.1-12.5%]) were EMA-positive, but all tests were low titer (< or = 1:20). However, none of the biopsies showed any histopathological features of CD, nor did EMA status correlate with any of the clinical or laboratory features assessed.

CONCLUSIONS

Despite a high rate of weakly positive antibody tests, our data do not support an increased prevalence of CD among asymptomatic patients referred for evaluation of low BMD. Without an increase over the background prevalence, the high cost of EMA testing argues against routine use of this test for screening of this population.

[Inflammation mediated osteopenia (IMO): therapeutic effect of D-hormone and the role of cytokines]

Inflammation-mediated osteopenia is an animal model for bone mass reduction following chronic inflammation. We found a reduction of calcitriol serum concentrations during the inflammatory process, in addition cytokines are increased. Treatment of the animals with calcitriol is able to prevent bone mass reduction and to preserve bone formation.

Decreased bone mineral density in HLA-B27 positive members of a family with osteogenesis imperfecta

We describe a family in which several members had osteogenesis imperfecta (OI) and/or were positive for HLA-B27. The proband, who had ankylosing spondylitis and OI, had severe osteoporosis with fractures continuing to occur in the late teens. Bone mineral density measurements in 5 family members and the proband, revealed more severe osteoporosis in those with positive HLA-B27.

T lymphocyte surface antigen markers in osteoporosis

Two distinct syndromes of osteoporosis have been postulated: type I, which is characterized by accelerated bone loss occurring in women during the early postmenopausal period; and type II, an age-related process of bone loss affecting both men and women in and after the seventh decade. Recently there has been indirect evidence linking local products of the immune system with bone remodeling. We therefore studied peripheral blood profiles of specific lymphocyte phenotypes in women with type I osteoporosis and in older women and men with type II osteoporosis. The ratio of CD4-bearing (T helper) cells to CD8-bearing (T cytotoxic-suppressor) cells (CD4/CD8 ratio) was elevated in women with symptomatic type I disease. In addition there was a significant negative correlation (r = -0.62, P less than 0.001) between the CD4/CD8 ratio and the spinal bone mineral density measured by dual-photon absorptiometry. In contrast, older men with a history of fracture (hip or spine) had CD4/CD8 ratios similar to control men. The number of T cells bearing IL-2R or VLA-1 was not different between osteoporotic subjects and controls in either men or women. This study supports the concept that local products of the immune system may be directly or indirectly involved in the pathogenesis of type I osteoporosis.

Quantitative bone histomorphometry and circulating T lymphocyte subsets in postmenopausal osteoporosis

To explore the influence of the immune system on the development of osteoporosis, 19 untreated postmenopausal women with osteoporosis were studied by means of quantitative histomorphometry of the ilium and an analysis of T lymphocyte subsets in the peripheral blood. Osteoporotic women had lower OKT3+ and OKT8+ counts and a higher OKT4+/OKT8+ ratio than nonosteoporotic control subjects. Linear regression analyses disclosed that the age of subjects correlated with bone mineral density (BMD; r = -0.634, p less than 0.01) and some of the histomorphometric parameters for bone formation (r = -0.694 to -0.467, p less than 0.01-0.05). The number of OKT4+ cells showed weak but significant negative correlation with the parameters for bone resorption (r = -0.549 to -0.462, p less than 0.05). In a multiple regression analysis, the advanced age, the increase in OKT3+, and the decrease in OKT4+ and OKT8+ counts were shown to be significant predictors for the decrease in BMD (R = 0.882, p less than 0.01). According to the regression formula obtained from the analysis, the parameters for bone formation were related only to the age of subjects whereas those for bone resorption were tightly associated with the number of OKT4+ and OKT8+ cells but not with the age of subjects. These results indicated that, in addition to the age factor, abnormalities of the peripheral T lymphocyte subsets, especially those of OKT4+ and OKT8+ cells, are closely associated with the decrease in bone mass in postmenopausal osteoporosis, supporting the causal relationship between T lymphocyte functions and the development of postmenopausal osteoporosis.