Increased serum fibroblast growth factor-23 and decreased bone turnover in patients with systemic lupus erythematosus under treatment with cyclosporine and steroid but not steroid only

Cyclosporine a inhibits bone regeneration and induces bone loss in a rat model

Cyclosporine A (CSA) is an immunosuppressant that has been extensively studied for its side effects on inhibiting osseointegration of titanium implants. However, the impact of CSA on bone healing in postmenopausal osteoporosis remains unknown. Therefore, this study aimed to investigate the effect of CSA on bone repair in an ovariectomized (OVX) rat model through both in vitro and in vivo experiments. We examined the interventions of CSA on osteoblast progenitor cells MC3T3-E1 and assessed their effects on biological function using RT-qPCR, CCK-8 assay, alizarin red staining, and alkaline phosphatase staining. Furthermore, we evaluated the effects of CSA on bone regeneration and bone mass in both OVX rat models and femoral diaphysis bone defect models. The results from the CCK-8 experiment indicated a positive influence of experimental doses of CSA on osteogenic differentiation of MC3T3-E1 cells. ALP expression levels and calcified nodules were also evaluated, suggesting that CSA intervention promoted osteogenic differentiation in MC3T3-E1 cells. Additionally, specific gene expressions including OPN, Runx-2, OC, and Col1a1 were up-regulated after CSA intervention. Biomechanical parameters aligned with histological analysis as well as micro-CT scans confirmed worse bone microstructure and strength following CSA intervention. Our findings preliminarily suggest that whether it is normal or osteoporotic bones, CSA has adverse effects on bone health which are associated with elevated-bone turnover.

Relationship of Fibroblast Growth Factor 23 Serum Levels with Disease Characteristics in Systemic Lupus Erythematosus Patients

Fibroblast growth factor 23 (FGF23), a hormone secreted by osteocytes and osteoblasts, is a major regulator of vitamin D and phosphate homeostasis. FGF23 has been associated with the disturbance of mineral homeostasis, and with kidney and cardiovascular diseases. Systemic lupus erythematosus (SLE) is an autoimmune disorder that can affect virtually any organ. In the present work, we set out to analyze the relationship of FGF23 with the expression of SLE, including patterns of activity, damage, and severity. A total of 284 well-characterized patients with SLE were recruited. Activity (SLEDAI), severity (Katz), and damage index (SLICC-DI) scores were determined. The serum levels of FGF23 were also assessed. Multivariable linear regression analysis was performed to study the relationship between disease characteristics and FGF23. FGF23 and 25(OH) vitamin D were negatively correlated. Furthermore, prednisone use was associated with higher circulating FGF23 after an adjustment for confounding factors. SLICC-DI was related to higher serum levels of FGF23 after a multivariable analysis. However, when the SLICC-DI index items and domains were analyzed separately, apart from proteinuria ≥3.5 gm/24 h, only the musculoskeletal domain, encompassing arthritis and osteoporosis, was significantly associated with higher serum levels of FGF23. In conclusion, an association is observed between elevated serum FGF23 levels and disease damage, particularly related to musculoskeletal complications and proteinuria, in patients with SLE.

Fibroblast growth factor 23 (Fgf23) levels and their relationship with disease activity, bone mineral density, and radiological damage score in patients with rheumatoid arthritis: a single center case–control study

Background

There is limited and conflicting information on Fgf23 levels and their relationship with bone loss and disease activity in rheumatoid arthritis (RA). The aim of this study was to compare Fgf23 levels in RA patients with a healthy population and to evaluate the relationship between Fgf23 levels in RA with disease activity, bone mineral density (BMD), and radiological damage score.

Results

The median Fgf23 levels in patients with RA and in hospital staff were 20.06 (11.2–51.0) and 26.40 (12.6–49.5) pg/ml (P < 0.001), respectively. RA patients were divided into active (DAS28 > 3.2) and inactive (DAS28 ≤ 3.2) subgroups. The median Fgf23 levels in active and inactive RA patients were 22.12 (13.90–51.02) and 17.71 (11.20–31.19) pg/ml, respectively (P = 0.001). BMD of RA patients was evaluated with dual-energy X-ray absorptiometry and radiological damage scores were evaluated independently by two investigators using the modified Sharp score (MSS). In RA patients, Fgf23 values correlated with DAS28 and with erosion score of observer-2 (r = 0.297, P = 0.036), but not with erosion score of observer-1 (r = 0.252, P = 0.077). No correlation was found between DAS28 and femur and lumbar vertebra BMD.

Conclusion

In RA, Fgf23 is not associated with BMD but may be associated with local bone loss and disease activity.

Skeletal health in patients following allogeneic hematopoietic cell transplantation

Allogeneic hematopoietic cell transplantation (HCT) is a potentially curative approach for patients with certain hematological diseases, including several forms of lymphoma and leukemia. Besides several treatment-associated risks, transplanted patients are at an increased risk of developing osteoporosis. The underlying pathophysiology is complex and includes factors influenced directly by the disease as well as applied therapies like irradiation, chemotherapy and adjuvant immunosuppressive agents. In addition, patients are prone to secondary hypogonadism, and many patients will require long-term glucocorticoid therapy to mitigate graft-versus-host reactions. All these factors contribute to bone loss, but the individual risk profile may vary greatly. This review summarizes our knowledge on bone loss following allogenic HCT and provides screening and treatment recommendations.

Uncoupled bone remodeling is characteristic of bone damage in premenopausal women with new-onset systemic lupus erythematosus

OBJECTIVE

To investigate the mechanism underlying systemic lupus erythematosus (SLE)-related bone loss by evaluating the bone mineral density (BMD) and bone turnover markers (BTMs) in premenopausal patients with new-onset SLE without any treatment.

METHODS

BMD and BTMs of 106 premenopausal patients with new-onset SLE and 64 gender-, age- and body mass index (BMI)-matched healthy controls were analyzed. BMD was determined using dual energy X-ray absorptiometry (DXA). Serum BTMs were measured.

RESULTS

Hip and lumbar spine BMD in premenopausal patients with new-onset SLE was significantly decreased compared with healthy controls. Higher rate of osteoporosis was observed in new-onset SLE patients (25% vs. 1%). Moreover, uncoupled bone remodeling evidenced by an increase in bone resorption marker β-CTX (685.9 ± 709.6 pg/mL vs. 395.4 ± 326.0 pg/mL, P < 0.05) and decrease in bone formation markers PINP (37.4 ± 33.0 ng/mL vs. 46.1 ± 20.9 ng/mL, P < 0.05) and OC (11.4 ± 9.8 ng/mL vs. 18.2 ± 8.6 ng/mL, P < 0.05) was observed in premenopausal patients with new-onset SLE compared with healthy controls. Univariate correlation analyses showed negative correlations between OC and SLE Disease Activity Index (SLEDAI), and positive correlations between β-CTX and SLEDAI. SLE patients positive for dsDNA, nucleosome showed lower OC and higher β-CTX.

CONCLUSION

Premenopausal patients with new-onset SLE had decreased BMD and abnormal bone metabolism with increased β-CTX and decreased OC and P1NP levels, indicating uncoupled bone remodeling in new-onset SLE patients. Disease activity and abnormal immunity, especially the amount of antibodies in SLE patients, were strongly associated with abnormality of bone metabolism.

Cyclosporine A impairs bone repair in critical defects filled with different osteoconductive bone substitutes

The aim of this study was to assess the influence of cyclosporine administration on the repair of critical-sized calvaria defects (CSDs) in rat calvaria filled with diverse biomaterials. Sixty animals were divided into two groups: the control (CTR) group (saline solution) and the cyclosporine (CCP) group (cyclosporine, 10 mg/kg/day). These medications were administered daily by gavage, beginning 15 days before the surgical procedure and lasting until the day the animals were euthanized. A CSD (5 mm Ø) was made in the calvaria of each animal, which was allocated to one of 3 subgroups, according to the biomaterial used to fill the defect: coagulum (COA), deproteinized bovine bone (DBB), or biphasic calcium phosphate ceramics of hydroxyapatite and β-phosphate tricalcium (HA/TCP). Euthanasia of the animals was performed 15 and 60 days after the surgical procedure (n = 5 animals/period/subgroup). Bone repair (formation) assessment was performed through microtomography and histometry, while the analyses of the expression of the BMP2, Osteocalcin, and TGFβ1 proteins were performed using immunohistochemistry. The CSDs not filled with biomaterials demonstrated lower bone formation in the CCP group. At 15 days, less bone formation was observed in the CSDs filled with DBB, a smaller volume of mineralized tissue was observed in the CSDs filled with HA/TCP, and the expression levels of BMP2 and osteocalcin were lower in the CCP group compared to the CTR group. The use of cyclosporine impaired bone repair in CSD, and this effect can be partially explained by the suppression of BMP2 and osteocalcin expression.

Bone Health in Glomerular Kidney Disease

PURPOSE OF REVIEW

To summarize the literature regarding alterations in bone health in patients with glomerular kidney disease and highlight areas in need of additional investigation.

RECENT FINDINGS

There is mounting evidence that children and adults with glomerular conditions, with or without compromised kidney function, comprise a distinct subgroup of patients with unique risk factors for altered bone health. Patients with glomerular kidney disease are exposed to both disease-related and treatment-related factors that affect bone structure and function. In addition to chronic kidney disease-related risk factors for impaired bone health, high rates of exposure to osteotoxic medications, varying degrees of systemic inflammation, and altered vitamin D metabolism may contribute to compromised bone health in individuals with glomerular disease. Further study is needed to better understand these risk factors and the complex interaction between the immune system and bone cells in glomerular disease.

Bone management in hematologic stem cell transplant recipients

Autologous and allogeneic hematopoietic stem cell transplantation (HSCT) is the treatment of choice for patients with some malignant and non-malignant hematological diseases. Advances in transplantation techniques and supportive care measures have substantially increased the number of long-term HSCT survivors. This has led to an increasing patient population suffering from the late effects of HSCT, of which, bone loss and its consequent fragility fractures lead to substantial morbidity. Altered bone health, with consequent fragility fractures, and chronic graft-versus-host disease (GVHD) are factors affecting long-term quality of life after HSCT. Hypogonadism, HSCT preparative regimens, nutritional factors, and glucocorticoids all contribute to accelerated bone loss and increased fracture risk. Management strategies should include bone mineral density examination, evaluation of clinical risk factors, and general dietary and physical activity measures. Evidence has accumulated permitting recommendations for more attentiveness to evaluation and monitoring of bone health, with appropriate application of osteoporosis pharmacotherapies to patients at increased risk of bone loss and fracture.

CYP3A4 is a crosslink between vitamin D and calcineurin inhibitors in solid organ transplant recipients: implications for bone health

The use of calcineurin inhibitors (CNIs) and vitamin D deficiency may contribute to the pathogenesis of post-transplant bone disease. CNIs and 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) are substrates of the drug-metabolizing enzyme CYP3A4. This review summarizes the indications for the use of activated vitamin D analogs in post-transplant care and the current knowledge on the impact of CNIs on bone. We searched for clinical evidence of the interaction between CNIs and 1,25(OH)₂D₃. We also provide an overview of the literature on the interplay between vitamin D metabolism and CYP3A4 in experimental and clinical settings and discuss its possible implications for solid organ transplant recipients. In conclusion, there is a body of evidence on the interplay between vitamin D and the drug-metabolizing enzyme CYP3A4, which may have therapeutic implications.