Evaluating the role of serum sclerostin as an indicator of activity and damage in Egyptian patients with rheumatoid arthritis: university hospital experience

Antioxidant and anti-arthritic activity of Bombax buonopozense P. Beauv. leaves

BACKGROUND AND AIM

Bombax buonopozense (Bombacaceae) leaves have been used traditionally for arthritis in south-western Nigeria. Therefore, the aim of the study was to investigate the antioxidant and anti-arthritic activity of B. buonopozense in Complete Freund adjuvant-induce arthritic wistar rats.

EXPERIMENTAL PROCEDURE

The plant leaves methanol extract and fractions were screened for preliminary phytochemicals and brine shrimp lethality was determined. Total phenolic content (TPC), Total flavonoid content (TFC) as well as anti-oxidant activity of the extract and fractions were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH). Cyclophosphamide, gallic acid, and ascorbic acid were used as standards respectively. Anti-arthritic activity of crude methanol extract (BBME) at 100, 200 and 400mg/kg was evaluated in complete Freund's adjuvant (CFA) induced arthritis model in rats. Data were analysed using Graph pad prism version 5, two-way and one-way ANOVA, and Bonferroni post hoc test.

RESULTS AND CONCLUSION

Phytochemical screening revealed the presence of flavonoids, alkaloids, and phenolics. The brine shrimp lethality assay of the crude extract and fractions gave LC50 value≥1000μg/mL, compared to Cyclophosphamide (LC50=224.7±0.35μg/mL). The BBME had TPC value of 19.8±0.56mg GAE/g, while the TFC of ethyl acetate fraction was the highest (173.5±0.05mg QE/g). The ethyl acetate fraction has the highest antioxidant activity (IC50=20.96±0.23μg/mL) as compared to ascorbic acid (2.8±0.01) and rutin (20.6±9.26μg/mL). BBME significantly reduced the paw circumference. BBME (400mg/kg) prevented biochemical changes to a greater extent than Celecoxib (20mg/kg). Bombax buonopozense leaves could be an effective antiarthritic and holds prospect in the treatment of rheumatoid arthritis.

Plasma Sclerostin Levels in Rheumatoid Arthritis Women on TNF-α Inhibitor Therapy

Rheumatoid arthritis (RA) is associated with significant systemic and local bone loss. The aim of this study was to assess whether or not 15-month tumor necrosis factor α inhibitor (TNFαI) therapy in combination with methotrexate (MTX) affects circulating levels of sclerostin (SOST) in female RA patients. Plasma levels of SOST were measured using immunoassays kits. Baseline SOST levels showed no significant differences between RA patients and control participants. Postmenopausal women with RA tended to have higher sclerostin levels than premenopausal woman with RA. After 15 months of treatment with TNFαI, plasma levels of SOST were decreased. Before starting biological therapy, circulating levels of SOST significantly correlated with the patient's age (p < 0.05) and the marker of inflammation, such as ESR (p < 0.05). Multivariate regression analysis showed that age was the only significant predictor for baseline SOST levels in women with RA (β = 0.008, p = 0.028, R2 model = 0.293). Moreover, a positive correlation between SOST levels and the 28 joint disease activity score value based on the erythrocyte sedimentation rate (DAS28-ESR) was found at baseline (p < 0.05), as well as after 15 months of biological therapy (p < 0.05). Thus, plasma SOST levels may be helpful for monitoring the efficacy of TNFαI treatment in RA patients. According to our results, TNFαI, in combination with MTX, has a beneficial effect on bone turnover with a significant reduction in bone metabolism marker SOST.

Bone Involvement in Rheumatoid Arthritis and Spondyloartritis: An Updated Review

Several rheumatologic diseases are primarily distinguished by their involvement of bone tissue, which not only serves as a mere target of the condition but often plays a pivotal role in its pathogenesis. This scenario is particularly prominent in chronic inflammatory arthritis such as rheumatoid arthritis (RA) and spondyloarthritis (SpA). Given the immunological and systemic nature of these diseases, in this review, we report an overview of the pathogenic mechanisms underlying specific bone involvement, focusing on the complex interactions that occur between bone tissue's own cells and the molecular and cellular actors of the immune system, a recent and fascinating field of interest defined as osteoimmunology. Specifically, we comprehensively elaborate on the distinct pathogenic mechanisms of bone erosion seen in both rheumatoid arthritis and spondyloarthritis, as well as the characteristic process of aberrant bone formation observed in spondyloarthritis. Lastly, chronic inflammatory arthritis leads to systemic bone involvement, resulting in systemic bone loss and consequent osteoporosis, along with increased skeletal fragility.

Klotho reduces the risk of osteoporosis in postmenopausal women: a cross-sectional study of the National Health and Nutrition Examination Survey (NHANES)

BACKGROUND

Osteoporosis (OP) is one of the diseases that endanger the health of the elderly population. Klotho protein is a hormone with anti-aging effects. A few studies have discussed the relationship between Klotho and OP. However, there is still a lack of research on larger populations. This study aims to evaluate the association between OP and Klotho in American postmenopausal women.

METHODS

This is a retrospective study. We searched the National Health and Nutrition Examination Survey (NHANES) database and collected data of 3 survey cycles, finally involving 871 postmenopausal women over 50 years old in the present study. All participants took dual-energy X-ray absorptiometry examination and serum Klotho testing at the time of investigation. After adjusting the possible confounding variables, a multivariate regression model was employed to estimate the relationship between OP and Klotho proteins. Besides, the P for trend and restricted cubic spline (RCS) were applied to examine the threshold effect and calculate the inflection point.

RESULTS

Factors influencing the occurrence of OP included age, ethnicity, body mass index and Klotho levels. Multivariate regression analysis indicated that the serum Klotho concentration was lower in OP patients than that in participants without OP (OR[log2Klotho] = 0.568, P = 0.027). The C-index of the prediction model built was 0.765, indicating good prediction performance. After adjusting the above-mentioned four variables, P values for trend showed significant differences between groups. RCSs revealed that when the Klotho concentration reached 824.09 pg/ml, the risk of OP decreased drastically.

CONCLUSION

Based on the analysis of the data collected from the NHANES database, we propose a correlation between Klotho and postmenopausal OP. A higher serum Klotho level is related to a lower incidence of OP. The findings of the present study can provide guidance for research on diagnosis and risk assessment of OP.

Increased circulating sclerostin levels in rheumatoid arthritis patients: an updated meta-analysis

BACKGROUND

Sclerostin, a regulator of bone metabolism and vascular calcification involved in regulating the Wnt/β-catenin signaling pathway, has been shown to be involved in the pathogenesis of rheumatoid arthritis (RA). However, current results regarding the circulating sclerostin level of RA patients are debatable. This study aimed to evaluate the circulating level of sclerostin in RA patients and briefly summarize its role.

METHOD

PubMed, EMBASE, and the Cochrane Library databases were systematically searched till May 27, 2021, for eligible articles. Useful data from all qualified papers were systematically extracted and analyzed using Stata 12.0 software (Stata Corp LP, College Station, TX, USA).

RESULTS

Overall, 13 qualifying studies including 1030 cases and 561 normal controls were analyzed in this updated meta-analysis. Forest plot of this meta-analysis showed that RA patients had higher circulating sclerostin levels (P < 0.001, standardized mean difference [SMD] = 0.916, 95% CI: 0.235-1.597) compared to normal controls. Subgroup analyses implied that age, region, and assay method were associated with sclerostin level in RA patients.

CONCLUSION

RA patients have higher circulating sclerostin levels, and these was influenced by age, region, and assay method.

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.

Role of Sclerostin in Cardiovascular Disease

Sclerostin is most recognized for its role in controlling bone formation but is also expressed in the heart, aorta, coronary, and peripheral arteries. This review summarizes research on sclerostin's role in cardiovascular disease. Rodent studies have found sclerostin to be expressed at sites of arterial calcification. In contrast, aortic sclerostin was reported to be downregulated in a mouse model of abdominal aortic aneurysm, and transgenic upregulation or administration of sclerostin was found to prevent abdominal aortic aneurysm and atherosclerosis formation. Sclerostin deficiency was reported to stimulate cardiac rupture in one rodent model. In humans, 7 of 11 studies reported a significant association between high serum sclerostin and high carotid intima media thickness. Ten of 15 studies reported a significant association between high serum sclerostin and severe arterial calcification. Twelve of 14 studies reported a significant association between high serum sclerostin and high arterial stiffness or atherosclerosis severity. Four of 9 studies reported a significant association between high serum sclerostin and high risk of cardiovascular events. A meta-analysis of randomized controlled trials suggested that administration of the sclerostin blocking antibody romosozumab did not significantly increase the risk of major adverse cardiovascular events (risk ratio, 1.14 [95% CI, 0.83-1.57]; P=0.54) or cardiovascular death (risk ratio, 0.92 [95% CI, 0.53-1.59]; P=0.71). Human genetic studies reported variants predisposing to low arterial sclerostin expression were associated with a high risk of cardiovascular events. Overall, past research suggests a cardiovascular protective role of sclerostin but findings have been inconsistent, possibly due to variations in study design, the unique populations and models studied, and the heterogeneous methods used.

Serum sclerostin in acute kidney injury patients

BACKGROUND

Many of the mineral metabolite abnormalities encountered in chronic kidney disease (CKD) patients were found also associated with acute kidney injury (AKI). In the last decade, sclerostin was found to intimately affect bone mineral metabolism in CKD patients. Nothing is known about sclerostin in AKI.

OBJECTIVE

We looked for serum level of sclerostin in AKI patients in comparison to normal control subjects and if there is an impact on metabolic derangement, endothelial function or clinical outcome.

CASES AND METHODS

This is a cross sectional case control observational study of 219 AKI cases (group I) beside 219 age matched normal control subjects (group II). All cases of group I were in the intensive care because of sepsis; 86 had acute on CKD (group Ib), while 133 had de novo AKI (group Ia). All studied subjects underwent estimation of serum sclerostin, parathyroid hormone (PTH), 25 hydroxy vitamin D (25 OH vit D), fibroblast growth factor 23 (FGF23), C-reactive protein (CRP), interleukin 6 (IL6), Homeostatic Model Assessment for Insulin Resistance (Homa IR), beside the routine CBC, kidney and liver function tests, serum calcium, and phosphorus, and flow mediated vasodilation of brachial artery (FMD). Follow-up of group I cases was done till they recovered or passed away.

RESULTS

Serum sclerostin, PTH, FGF23, phosphorus, CRP, IL6, HOMA IR, creatinine, urea, uric acid, ALT, AST and white blood cell count (WBC) were significantly higher while serum calcium, 25 OH vit D, hemoglobin, platelet count and FMD were significantly lower in group I compared to group II (P<0.001 in all). On the other hand, there was no significant difference in serum sclerostin, PTH, FGfF23, 25 OH vit D, CRP, IL6, Homa IR and FMD between group Ia and Ib. Survivors were younger in age (median 55.5 vs. 60 years, P<0.04), had lower AST (30.5 vs. 58 units, P<0.001), had higher platelet count (206 vs 162×10⁹/L, P<0.001), otherwise, there was no significant difference in any of the other parameters between survivors and patients that were lost. Serum sclerostin had strong correlation with FGF23 in group I (r=0.99, P<0.001) and group II (r=1, P<0.001). Homa IR had positive correlation with serum sclerostin (r=0.148, P=0.014) and serum FGF23 (r=0.142, P=0.018) in group I.

CONCLUSION

Sclerostin is intimately related to FGF23. Sclerostin level increases in AKI patients. Both sclerostin and FGF23 might increase insulin resistance but have no impact on FMD. Neither sclerostin nor FGF23 interfere with AKI outcome.

Understanding the Stony Bridge between Osteoporosis and Vascular Calcification: Impact of the FGF23/Klotho axis

A relationship between osteoporosis (OP) and vascular calcification (VC) is now proposed. There are common mechanisms underlying the regulation of them. Fibroblast growth factor- (FGF-) 23 and Klotho are hormones associated with the metabolic axis of osteovascular metabolism. Most recently, it was suggested that the FGF23-klotho axis is associated with increasing incidence of fractures and is potentially involved in the progression of the aortic-brachial stiffness ratio. Herein, we discussed the potential role of the FGF23/Klotho axis in the pathophysiology of OP and VC. We want to provide an update review in order to allow a better understanding of the potential role of the FGF23/Klotho axis in comorbidity of OP and VC. We believe that a better understanding of the relationship between both entities can help in proposing new therapeutic targets for reducing the increasing prevalence of OP and VC in the aging population.

Serum sclerostin in acute kidney injury patients

BACKGROUND

Many of the mineral metabolite abnormalities encountered in chronic kidney disease (CKD) patients were found also associated with acute kidney injury (AKI). In the last decade, sclerostin was found to intimately affect bone mineral metabolism in CKD patients. Nothing is known about sclerostin in AKI.

OBJECTIVE

We looked for serum level of sclerostin in AKI patients in comparison to normal control subjects and if there is an impact on metabolic derangement, endothelial function or clinical outcome.

CASES AND METHODS

This is a cross sectional case control observational study of 219 AKI cases (group I) beside 219 age matched normal control subjects (group II). All cases of group I were in the intensive care because of sepsis; 86 had acute on CKD (group Ib), while 133 had de novo AKI (group Ia). All studied subjects underwent estimation of serum sclerostin, parathyroid hormone (PTH), 25 hydroxy vitamin D (25 OH vit D), fibroblast growth factor 23 (FGF23), C-reactive protein (CRP), interleukin 6 (IL6), Homeostatic Model Assessment for Insulin Resistance (Homa IR), beside the routine CBC, kidney and liver function tests, serum calcium, and phosphorus, and flow mediated vasodilation of brachial artery (FMD). Follow-up of group I cases was done till they recovered or passed away.

RESULTS

Serum sclerostin, PTH, FGF23, phosphorus, CRP, IL6, HOMA IR, creatinine, urea, uric acid, ALT, AST and white blood cell count (WBC) were significantly higher while serum calcium, 25 OH vit D, hemoglobin, platelet count and FMD were significantly lower in group I compared to group II (P<0.001 in all). On the other hand, there was no significant difference in serum sclerostin, PTH, FGfF23, 25 OH vit D, CRP, IL6, Homa IR and FMD between group Ia and Ib. Survivors were younger in age (median 55.5 vs. 60 years, P<0.04), had lower AST (30.5 vs. 58 units, P<0.001), had higher platelet count (206 vs 162×109/L, P<0.001), otherwise, there was no significant difference in any of the other parameters between survivors and patients that were lost. Serum sclerostin had strong correlation with FGF23 in group I (r=0.99, P<0.001) and group II (r=1, P<0.001). Homa IR had positive correlation with serum sclerostin (r=0.148, P=0.014) and serum FGF23 (r=0.142, P=0.018) in group I.

CONCLUSION

Sclerostin is intimately related to FGF23. Sclerostin level increases in AKI patients. Both sclerostin and FGF23 might increase insulin resistance but have no impact on FMD. Neither sclerostin nor FGF23 interfere with AKI outcome.

Structural damage in rheumatoid arthritis assessed by musculoskeletal ultrasound: A systematic literature review by the Structural Joint Damage Task Force of the OMERACT Ultrasound Working Group

OBJECTIVES

To identify and synthesize the evidence for the use and measurement properties of musculoskeletal ultrasound in assessing structural joint damage in patients with rheumatoid arthritis (RA).

METHODS

A systematic literature search (SLR) of the PubMed, Embase and Cochrane Library was performed. Original articles were included published in English reporting on ultrasound of bone erosion, cartilage damage and the measurement properties of ultrasound according to the OMERACT filter 2.1.

RESULTS

Of the 1.495 identified articles 149 were included in the final review, most of which reported on cross-sectional studies and used the OMERACT definitions for ultrasonographic pathology. Among these, bone erosions were assessed in 139 (93.3%), cartilage damage in 24 (16.1%), enthesophytes in 8 (5.4%), osteophytes in 15 (10.1%) and malalignment and ankylosis in a single (0.9%) study, respectively. Most studies (126/149, 84.6%) assessed the joints of the hands. The overwhelming majority of studies (127/149, 85.2%) assessed structural joint damage bilaterally. Validity, reliability and responsiveness were assessed in 21 (14.1%), 34 (22.8%) and 17 (11.4%) studies, respectively.

CONCLUSION

While the results of this SLR suggest that ultrasound is a sensitive, reliable and feasible tool to detect damage in RA, they also highlight the need for further research and validation. Findings of this SLR will inform the next steps of the OMERACT Ultrasound Working Group in developing an ultrasound score for assessing structural joint damage in patients with RA.

Klotho/FGF23 and Wnt Signaling as Important Players in the Comorbidities Associated with Chronic Kidney Disease

Fibroblast Growth Factor 23 (FGF23) and Klotho play an essential role in the regulation of mineral metabolism, and both are altered as a consequence of renal failure. FGF23 increases to augment phosphaturia, which prevents phosphate accumulation at the early stages of chronic kidney disease (CKD). This effect of FGF23 requires the presence of Klotho in the renal tubules. However, Klotho expression is reduced as soon as renal function is starting to fail to generate a state of FGF23 resistance. Changes in these proteins directly affect to other mineral metabolism parameters; they may affect renal function and can produce damage in other organs such as bone, heart, or vessels. Some of the mechanisms responsible for the changes in FGF23 and Klotho levels are related to modifications in the Wnt signaling. This review examines the link between FGF23/Klotho and Wnt/β-catenin in different organs: kidney, heart, and bone. Activation of the canonical Wnt signaling produces changes in FGF23 and Klotho and vice versa; therefore, this pathway emerges as a potential therapeutic target that may help to prevent CKD-associated complications.