Serum HMGB1 Serves as a Novel Laboratory Indicator Reflecting Disease Activity and Treatment Response in Ankylosing Spondylitis Patients

Could serum HMGB1 levels be a predictor associated with psoriatic arthritis?

Background/aim: Psoriasis is a chronic autoimmune disease that predominantly affects the skin and musculoskeletal system. We hypothesized that HMGB1, an inflammatory nuclear protein, may play a role in the musculoskeletal involvement of psoriasis. Methods: Forty patients with psoriasis and 45 with psoriatic arthritis were involved in the study; the results were compared with 22 healthy controls. Serum HMGB1 levels were evaluated from peripheral blood samples. Results: Serum HMGB1 levels were found to be significantly higher in patients with psoriasis regardless of joint involvement (p < 0.001). Also, HMGB1 levels were correlated with the extent of psoriasis. Conclusion: Serum HMGB1 levels may contribute to the progression of psoriasis to psoriatic arthritis and correlate with the severity of skin involvement.

The Role of HMGB1 in Rheumatic Diseases

HMGB1, a highly conserved non-histone nuclear protein, is widely expressed in mammalian cells. HMGB1 in the nucleus binds to the deoxyribonucleic acid (DNA) to regulate the structure of chromosomes and maintain the transcription, replication, DNA repair, and nucleosome assembly. HMGB1 is actively or passively released into the extracellular region during cells activation or necrosis. Extracellular HMGB1 as an alarmin can initiate immune response alone or combined with other substances such as nucleic acid to participate in multiple biological processes. It has been reported that HMGB1 is involved in various inflammatory responses and autoimmunity. This review article summarizes the physiological function of HMGB1, the post-translational modification of HMGB1, its interaction with different receptors, and its recent advances in rheumatic diseases and strategies for targeted therapy.

Biomarkers in axial spondyloarthritis and low back pain: a comprehensive review

The spectrum of axial spondyloarthritis (AxSpA) (including both non-radiographic and radiographic AxSpA), also known as ankylosing spondylitis AS, has achieved growing recognition. With the development of treatments not only effective in controlling disease activity but also in slowing radiographic progression, and given the cost and risk profiles of these novel treatments and the limitations of current clinical criteria, imaging and peripheral blood biomarkers (C-reactive protein, HLA-B27 testing), the need for better biomarkers has never been greater. The purpose of this review is to present up-to-date information on the biomarkers for the diagnosis for assessing disease diagnosis, activity, treatment response, and radiographic progression of AxSpA, and entails multiple search strings used to identify articles of interest published in PubMed and the Cochrane database up to May 1, 2021. We present the current status of research in serologic biomarkers such as cytokines, adipokines, matrix metalloproteinases, calprotectin, CD74, antibodies, bone turnover markers, and circulating protein fragments of cartilage and connective tissue degradation and other biomarkers. Despite a great deal of work, most serologic results have been disappointing and to date none perform better than CRP. Recent promising preliminary data for some has been published, but require further confirmation. Transcriptomic biomarkers such as micro-RNAs and genetic biomarkers also show promise to assist in diagnosis and possibly for radiographic severity, including a recently developed panel of genetic risk markers used in a polygenic risk score instrument in AS diagnosis. These need further confirmation and application in AS as well as in nr-AxSpA.

High mobility group box-1 levels may be associated with disease activity of Behcet's disease

BACKGROUND

High mobility group box- 1 (HMGB- 1) is a nuclear protein acting as a proinflammatory molecule. The serum HMGB- 1 levels were found elevated in chronic inflammatory diseases. In this cross-sectional study, serum HMGB- 1 levels in Behcet's disease (BD) patients and healthy controls (HC) were studied. Also, its association with disease activity scores and clinical findings were evaluated.

METHODS

Ninety BD patients and 50 age-sex matched HC were included in the study. Disease activity scores were assessed by Behcet Disease Current Activity Form (BDCAF) and Behcet Syndrome Activity Score (BSAS). Serum HMGB- 1 levels were measured using a commercial ELISA kit. A p value of < 0.05 was considered to be statistically significant.

RESULTS

Serum HMGB- 1 levels were significantly higher in BD than in HC (43.26 pg/mL and 16.73 pg/mL; p < 0.001, respectively). Serum HMGB- 1 levels were statistically significantly associated with presence of erythema nodosum (EN) and genital ulcers in the last one month prior to recruitment (p = 0.041 and p < 0.001, respectively). BDCAF and BSAS scores were positively correlated with serum HMGB- 1 level ( p = 0.03 and p = 0.02, respectively).

DISCUSSION

HMGB - 1 may play a role in the development of BD. Also, due to its positive correlation with disease activity indices, it can be used as a novel disease activity parameter in BD.

Association between high mobility group box 1 protein and juvenile idiopathic arthritis: a prospective longitudinal study

OBJECTIVE

To analyze the levels of high mobility group box 1 (HMGB1) protein on different courses of juvenile idiopathic arthritis (JIA).

METHODS

In our prospective longitudinal study, children with JIA were included with their blood samples collected at the first visit, 1-month, 3-month, and 6-month follow-up, respectively. Samples were also collected from healthy controls and children with reactive arthritis at the first visit. Levels of HMGB1 were determined using enzyme-linked immunosorbent assays. Clinical disease characteristics and routine laboratory findings were analyzed as well.

RESULTS

A total of 64 children were enrolled, of whom 31 (48.4%) were female. The median age at the first visit for participants with JIA was 9.25 years (range, 1.42-15.42) and the median duration of disease was 2.38 months (range, 1.53-49.31). Serum HMGB1 levels at the first visit were significantly elevated in children with systemic JIA compared with other groups, and so were in enthesitis-related arthritis versus healthy controls. Significant correlations were established at the first visit between HMGB1 levels and duration of disease, C-reactive protein, percentage of neutrophils, and ferritin. Data from all samples revealed that serum HMGB1 levels in JIA were significantly associated with erythrocyte sedimentation rates, C-reactive protein, percentage of neutrophils, and disease activity scores.

CONCLUSIONS

Serum HMGB1 may be associated with clinical disease activity of JIA and specifically increased at the first visit in children with systemic JIA, suggesting its function as a sensitive inflammatory marker. Further large-scale studies are warranted to explore its spectrum in JIA.

Association Between Serum Alarmin Levels and Disease-specific Indices in Patients With Anti-neutrophil Cytoplasmic Antibody-associated Vasculitis

BACKGROUND/AIM

We evaluated the relationship between serum alarmin levels and disease-specific indices in patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

PATIENTS AND METHODS

Sera and data from 79 patients were utilized. For AAV-specific indices, Birmingham vasculitis activity score (BVAS), five-factor score (FFS), and vasculitis damage index (VDI) were collected and serum levels of four alarmins (hepatoma-derived growth factor, high mobility group box protein 1, S100A9, and S100A12) were measured using enzyme-linked immunosorbent assay. Associations between alarmin levels, AAV-specific indices, and inflammatory laboratory markers were assessed.

RESULTS

S100A9 levels were significantly correlated with C-reactive protein levels (r=0.316, p=0.005) and S100A12 levels correlated with VDI (r=0.232, p=0.040), which was consistent in a subgroup of patients with myeloperoxidase (perinuclear)-ANCA positivity. No other associations were found between alarmin levels and BVAS, FFS, and VDI.

CONCLUSION

The serum S100A12 level was associated with organ damage in AAV, especially in myeloperoxidase (perinuclear)-ANCA-positive patients.

LPS Primes Brain Responsiveness to High Mobility Group Box-1 Protein

High mobility group box (HMGB)1 action contributes to late phases of sepsis, but the effects of increased endogenous plasma HMGB1 levels on brain cells during inflammation are unclear. Here, we aimed to further investigate the role of HMGB1 in the brain during septic-like lipopolysaccharide-induced inflammation in rats (LPS, 10 mg/kg, i.p.). HMGB-1 mRNA expression and release were measured in the periphery/brain by RT-PCR, immunohistochemistry and ELISA. In vitro experiments with disulfide-HMGB1 in primary neuro-glial cell cultures of the area postrema (AP), a circumventricular organ with a leaky blood–brain barrier and direct access to circulating mediators like HMGB1 and LPS, were performed to determine the direct influence of HMGB1 on this pivotal brain structure for immune-to-brain communication. Indeed, HMGB1 plasma levels stayed elevated after LPS injection. Immunohistochemistry of brains and AP cultures confirmed LPS-stimulated cytoplasmatic translocation of HMGB1 indicative of local HMGB1 release. Moreover, disulfide-HMGB1 stimulation induced nuclear factor (NF)-κB activation and a significant release of interleukin-6, but not tumor necrosis factor α, into AP culture supernatants. However, only a few AP cells directly responded to HMGB1 with increased intracellular calcium concentration. Interestingly, priming with LPS induced a seven-fold higher percentage of responsive cells to HMGB1. We conclude that, as a humoral and local mediator, HMGB1 enhances brain inflammatory responses, after LPS priming, linked to sustained sepsis symptoms.

Intestinal and enthesis innate immunity in early axial spondyloarthropathy

Axial SpA (axSpA), encompassing AS, is a multifactorial disease that localizes to sites of high spinal biomechanical stress. Much has been written on T cells and adaptive immunity in axSpA, which is understandable given the very strong HLA-B27 disease association. Extra-axial disease characteristically involves the anterior uveal tract, aortic root, lung apex and terminal ileum. Under recent classification, axSpA is classified as an intermediate between autoimmunity and autoinflammatory disease, with the latter term being synonymous with innate immune dysregulation. The purpose of this review is to evaluate the ‘danger signals’ from both the exogenous intestinal microbiotal adjuvants or pathogen-associated molecular patterns that access the circulation and endogenously derived damaged self-tissue or damage-associated molecular patterns derived from entheses and other sites of high biomechanical stress or damage that may serve as key drivers of axSpA onset, evolution, disease flares and eventual outcomes.

Survivin modulatory role in autoimmune and autoinflammatory diseases

Baculoviral IAP repeat containing 5 (BIRC5) gene encodes the important protein as survivin, a multifunctional protein, which is involved in cellular and molecular networks, progression of cell cycle, homeostasis, developmental morphogenesis, and apoptosis. The proximal BIRC5 promoter possesses specific binding sites for key transcription factors such as nuclear factor κB and signal transducer and activator of transcription 3. Upregulation of survivin exacerbates the autoimmune diseases (AIDs) including multiple sclerosis and myasthenia gravis by reducing the activity threshold of survivin-specific cytotoxic T cells. DNA damage along with upregulation or downregulation of survivin have been demonstrated in initiation and pathogenesis of cancers and AIDs. However, detailed mechanism of survivin function in pathogenesis of AIDs is not well understood. This review focuses on the structure, specificity, regulation, and function of survivin in physiologic conditions and pathogenesis of AIDs.

Association of serum/plasma high mobility group box 1 with autoimmune diseases: A systematic review and meta-analysis

BACKGROUND

High mobility group box 1 (HMGB1) is a kind of proinflammatory mediator to stimulate the innate and adaptive immune system and participates in a number of acute and chronic inflammatory processes after sterile injury or microbial invasion. HMGB1 has been suggested to be involved in the pathogenesis of many autoimmune diseases. However, the results are contradictory or inconclusive among these findings. The aim of this study was to investigate whether serum/plasma HMGB1 levels are associated with autoimmune diseases by comparing the serum/plasma HMGB1 levels in patients with autoimmune disease and healthy controls and to further evaluate whether serum/plasma HMGB1 levels are associated with disease state.

METHODS

PubMed, Medline, and Web of science databases (up to October 1, 2017) were used to obtain all relative published literature. Study quality was assessed by the Newcastle-Ottawa scale (NOS). Pooled standard mean difference (SMD) with 95% confidence interval (CI) was calculated by fixed-effects or random-effect model analysis.

RESULTS

A total of 23 original articles of autoimmune diseases were finally included in the meta-analysis. Results revealed that the serum/plasma HMGB1 levels were increased in patients with autoimmune disease, compared to healthy controls. Subgroup analysis showed that serum/plasma HMGB1 levels in patients with active disease state were significantly higher than in those with inactive state. In addition, subgroup analysis based on disease type has indicated that the serum/plasma HMGB1 levels in patients with small vessel vasculitis, systemic lupus erythematosus, rheumatoid arthritis, ankylosing spondylitis and sjogren syndrome were significantly higher, compared to healthy controls. Further subgroup analyses by region showed that plasma/serum HMGB1 levels were higher in Asian and European patients with autoimmune diseases.

CONCLUSIONS

Serum/plasma HMGB1 levels in patients with autoimmune diseases are significantly higher than in healthy controls, and may reflect the disease activity.