Serum levels of fetuin-A as a novel biomarker for disease activity in patients with Takayasu arteritis and granulomatous polyangiitis

Circulating Fetuin-A concentrations in rheumatic diseases: a systematic review and meta-analysis

BACKGROUND

Rheumatic diseases (RDs) include a broad group of disabling conditions with different phenotypes, from autoimmune to autoinflammatory, degenerative, metabolic or mixed manifestations. With the continuous efforts to identify therapeutic targets for new biologic drugs to treat overt clinical manifestations, research is also focusing on the discovery of new biomarkers to diagnose and manage early disease stages. In this context, we conducted a systematic review and meta-analysis of Fetuin-A (FtA), a glycoprotein synthesized by the liver that participates in several biological processes and has been proposed as a biomarker for several disorders, including rheumatoid arthritis.

METHODS

A systematic search in PubMed, Scopus and Web of Science, from inception to the 24th of August 2024, led to the identification of 13 manuscripts from 219 records; six additional studies were identified through reference hand-search, for a total of 19 studies.

RESULTS

There was a significant decrease in FtA concentrations in RD patients (standardized mean difference, SMD = -.91; 95% CI -1.43 to -.39, p = .001), with no substantial contribution from any individual study nor publication bias. The effect size was significantly associated with erythrocyte sedimentation rate, various lipid fractions, geographical area of study conduction, study design and specific type of RD.

CONCLUSION

In conclusion, our study identified significant reductions in FtA concentrations in RD patients versus healthy controls. These alterations were significantly associated with specific study and patient characteristics. Further research is required to identify the exact pathophysiological mechanisms underlying these alterations and the possible utility of measuring FtA for the diagnosis and management of RDs.

Medium-vessel and large-vessel vasculitis in children

PURPOSE OF REVIEW

This article serves as an up-to-date examination of the latest findings in the field of paediatric large-vessel and medium-vessel vasculitis.

RECENT FINDINGS

Over the last 2 years and in the wake of SARS-CoV2 pandemic, a multitude of studies have increased our insight into these conditions. Although large-vessel and medium-vessel vasculitis are uncommon amongst children, they are a complex and multisystem with a constantly evolving landscape. Increasing numbers of reports from low-income and middle-income countries are shaping our understanding of the epidemiology of vasculitis in children. The influence of infectious disease and the microbiome are of particular interest in unravelling pathogenetic aspects. Improved understanding of the genetics and immunology offer opportunities for better diagnostic options and biomarkers of disease as well as targeted therapies.

SUMMARY

In this review, we address recent findings in epidemiology, pathophysiology, clinical findings, bio-markers, imaging and treatment that have the potential to offer better management solutions for these uncommon conditions.

Proteomics analyses of acute kidney injury biomarkers in a rat exertional heat stroke model

The frequency of exertional heat stroke (EHS) increases with the gradual elevation of global temperatures during summer. Acute kidney injury (AKI) is a common complication of EHS, and its occurrence often indicates the worsening of a patient's condition or a poor prognosis. In this study, a rat model of AKI caused by EHS was established, and the reliability of the model was evaluated by HE staining and biochemical assays. The expression of kidney tissue proteins in the EHS rats was analyzed using label-free liquid chromatography-tandem mass spectrometry. A total of 3,129 differentially expressed proteins (DEPs) were obtained, and 10 key proteins were finally identified, which included three upregulated proteins (Ahsg, Bpgm, and Litaf) and seven downregulated proteins (medium-chain acyl-CoA synthetase 2 (Acsm2), Hadha, Keg1, Sh3glb1, Eif3d, Ambp, and Ddah2). The qPCR technique was used to validate these 10 potential biomarkers in rat kidney and urine. In addition, Acsm2 and Ahsg were double-validated by Western blotting. Overall, this study identified 10 reliable biomarkers that may provide potential targets for the treatment of AKI caused by EHS.

Outcome Measures and Biomarkers for Disease Assessment in Takayasu Arteritis

Takayasu arteritis (TAK) is a less common large vessel vasculitis where histopathology of involved arteries is difficult to access except during open surgical procedures. Assessment of disease activity in TAK, therefore, relies on surrogate measures. Clinical disease activity measures such as the National Institutes of Health (NIH) score, the Disease Extent Index in TAK (DEI.TAK) and the Indian TAK Clinical Activity Score (ITAS2010) inconsistently associate with acute phase reactants (APRs). Computerized tomographic angiography (CTA), magnetic resonance angiography (MRA), or color Doppler Ultrasound (CDUS) enables anatomical characterization of stenosis, dilatation, and vessel wall characteristics. Vascular wall uptake of 18-fluorodeoxyglucose or other ligands using positron emission tomography computerized tomography (PET-CT) helps assess metabolic activity, which reflects disease activity well in a subset of TAK with normal APRs. Angiographic scoring systems to quantitate the extent of vascular involvement in TAK have been developed recently. Erythrocyte sedimentation rate and C-reactive protein have a moderate performance in distinguishing active TAK. Numerous novel biomarkers are under evaluation in TAK. Limited literature suggests a better assessment of active disease by combining APRs, PET-CT, and circulating biomarkers. Validated damage indices and patient-reported outcome measures specific to TAK are lacking. Few biomarkers have been evaluated to reflect vascular damage in TAK and constitute important research agenda.