S100 proteins are currently being investigated as potential diagnostic and prognostic biomarkers of several cancers and inflammatory diseases. The aims of this study were to analyse the plasma levels of S100A4, S100A8/9 and S100A12 in patients with incomplete systemic lupus erythematosus (iSLE), in patients with established SLE and in healthy controls (HCs) and to investigate the potential utility of the S100 proteins as diagnostic or activity-specific biomarkers in SLE. Plasma levels were measured by ELISA in a cross-sectional cohort study of 44 patients with SLE, 8 patients with iSLE and 43 HCs. Disease activity was assessed using the SLEDAI-2K. The mean levels of all S100 proteins were significantly higher in SLE patients compared to HCs. In iSLE patients, the levels of S100A4 and S100A12 but not S100A8/9 were also significantly higher compared to HCs. There were no significant differences in S100 levels between the iSLE and SLE patients. Plasma S100 proteins levels effectively discriminated between SLE patients and HCs. The area under the curve (AUC) for S100A4, S100A8/9 and S100A12 plasma levels was 0.989 (95% CI 0.976-1.000), 0.678 (95% CI 0.563-0.792) and 0.807 (95% CI 0.715-0.899), respectively. S100 levels did not differentiate between patients with high and low disease activity. Only the S100A12 levels were significantly associated with SLEDAI-2K and with cSLEDAI-2K. S100 proteins were significantly higher in SLE patients compared HCs and particularly S100A4 could be proposed as a potential diagnostic biomarker for SLE.

• Keywords
• Biomarkers, Disease activity, S100 proteins, SLE,
• MeSH
• Adult MeSH
• Calgranulin A blood   MeSH
• Calgranulin B blood   MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• S100A12 Protein blood   MeSH
• S100 Proteins blood   MeSH
• Cross-Sectional Studies MeSH
• S100 Calcium-Binding Protein A4 blood   MeSH
• Case-Control Studies MeSH
• Lupus Erythematosus, Systemic blood   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Calgranulin A MeSH
• Calgranulin B MeSH
• S100A12 Protein MeSH
• S100 Proteins MeSH
• S100 Calcium-Binding Protein A4 MeSH
• S100A12 protein, human MeSH Browser
• S100A4 protein, human MeSH Browser
• S100A8 protein, human MeSH Browser
• S100A9 protein, human MeSH Browser

Approximately half of patients with rheumatoid arthritis (RA) have normal C-reactive protein (CRP) levels. Calprotectin is a promising and likely more specific biomarker of disease activity than conventionally used acute phase reactants. We aimed to analyse the levels of serum calprotectin in RA patients with clinically active disease and with normal/low CRP. A total of 160 RA patients underwent clinical examination (DAS28-ESR and CDAI). The levels of calprotectin were analysed in patients with moderate to high disease activity with normal/low CRP levels and in 32 healthy subjects. The discriminatory capacity of calprotectin to identify clinically active patients in spite of normal/low CRP was assessed using ROC curves. Out of all RA patients, 74/160 (46.3%) were in remission or had low disease activity according to DAS28 and had normal/low CRP levels. However, 51/160 (32%) had normal/low CRP levels despite having moderate to high disease activity. In these patients, calprotectin levels were significantly higher than those in patients who had normal/low CRP and were in remission or showed low disease activity (2.7 ± 1.5 vs. 2.1 ± 1.2 μg/mL, p = 0.043), which differed from those in healthy subjects (2.7 ± 1.5 vs. 1.9 ± 1.2 μg/mL, p = 0.011). The discriminatory capacity for calprotectin to distinguish clinically active vs. inactive disease despite normal/low CRP using AUC of the DAS28 was 0.607 (95% CI 0.503 to 0.711, p = 0.043). The present study demonstrates that calprotectin may reflect inflammatory activity in RA patients where CRP fails to do so.

• Keywords
• C-reactive protein, Calprotectin, Inflammation, Rheumatoid arthritis,
• MeSH
• Biomarkers blood   MeSH
• C-Reactive Protein analysis   MeSH
• Blood Sedimentation MeSH
• Leukocyte L1 Antigen Complex blood   MeSH
• Middle Aged MeSH
• Humans MeSH
• Reference Values MeSH
• Arthritis, Rheumatoid blood   MeSH
• Severity of Illness Index MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Finland MeSH
• Names of Substances
• Biomarkers MeSH
• C-Reactive Protein MeSH
• Leukocyte L1 Antigen Complex MeSH

BACKGROUND: Calprotectin may be a sensitive biomarker of rheumatoid arthritis (RA) disease activity. OBJECTIVES: In the current study, we investigated whether calprotectin is a better biomarker than CRP for predicting clinical activity and ultrasound parameters in patients with RA. METHODS: A total of 160 patients with RA underwent clinical (swollen joint count-SJC, tender joint count-TJC, Disease Activity Score-DAS28, Clinical Disease Activity Index-CDAI, and simplified Disease Activity Index-SDAI) and ultrasound (German US7) examination. Clinical and laboratory measures were correlated with ultrasound findings using Spearman´s correlation coefficient. Differences in serum calprotectin levels in patients with variable disease activity according to the DAS28-ESR and CDAI scores were assessed using ANOVA. Multivariate regression analysis was used to determine the predictive values of calprotectin, CRP and SJC for CDAI and PD US synovitis scores. RESULTS: Serum calprotectin was significantly associated with DAS28-ESR (r = 0.321, p<0.001), DAS28-CRP (r = 0.346, p<0.001), SDAI (r = 0.305, p<0.001), CDAI (r = 0.279, p<0.001) scores and CRP levels (r = 0.556, p<0.001). Moreover, calprotectin was significantly correlated with GS (r = 0.379, p<0.001) and PD synovitis scores (r = 0.419, p<0.001). The multivariate regression analysis showed that calprotectin is a better predictor of the CDAI score and PD US synovitis than CRP. CONCLUSIONS: The results of this study support an additional role of calprotectin in assessing inflammatory activity in patients with RA.

• MeSH
• C-Reactive Protein metabolism   MeSH
• Adult MeSH
• Cohort Studies MeSH
• Leukocyte L1 Antigen Complex blood   MeSH
• Middle Aged MeSH
• Humans MeSH
• Arthritis, Rheumatoid blood   diagnostic imaging   pathology   MeSH
• Ultrasonography MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• C-Reactive Protein MeSH
• Leukocyte L1 Antigen Complex MeSH

BACKGROUND: Calgizzarin (S100A11) is a member of the S100 protein family that acts in different tumors by regulating a number of biologic functions. Recent data suggest its association with low-grade inflammation in osteoarthritis (OA). The aim of our study is to compare S100A11 expression in the synovial tissues, synovial fluid and serum of patients with rheumatoid arthritis (RA) and osteoarthritis (OA) and to characterize the potential association between S100A11 and disease activity. METHODS: S100A11 protein expression was detected in synovial tissue from patients with RA (n = 6) and patients with OA (n = 6) by immunohistochemistry and immunofluorescence. Serum and synovial fluid S100A11 levels were measured by ELISA in patients with RA (n = 40) and patients with OA (n = 34). Disease activity scores in 28 joints based on C-reactive protein (DAS28-CRP) were used to assess disease activity. Cytokine content in peripheral blood mononuclear cells (PBMCs), synovial fibroblasts (SFs) and synovial fluid was analysed by ELISA, western blotting or cytometric bead array. RESULTS: S100A11 expression was significantly up-regulated in the synovial lining and sublining layers (p < 0.01) and vessels (p < 0.05) of patients with RA compared to patients with OA, and was associated with fibroblasts and T cells. S100A11 was significantly increased in synovial fluid (p < 0.0001) but not in serum (p = 0.158) from patients with RA compared to patients with OA when adjusted for age and sex. Synovial fluid S100A11 correlated with DAS28 (r = 0.350, p = 0.027), serum CRP (r = 0.463, p = 0.003), synovial fluid leukocyte count (r = 0.677, p < 0.001), anti-cyclic citrullinated peptide antibodies (anti-CCP) (r = 0.424, p = 0.006) and IL-6 (r = 0.578, p = 0.002) and IL-8 (r = 0.740, p < 0.001) in synovial fluid from patients with RA. PBMCs and SFs isolated from patients with RA synthesized and spontaneously secreted higher levels of S100A11 in comparison with PBMCs and SFs from patients with OA (p = 0.011 and 0.03, respectively). S100A11 stimulated the production of the pro-inflammatory cytokine IL-6 by PBMCs (p < 0.05) and SFs (p < 0.01). CONCLUSIONS: Our data provide the first evidence of S100A11 up-regulation and its association with inflammation and disease activity in patients with RA.

• Keywords
• Calgizzarin, Disease activity, Inflammation, Rheumatoid arthritis, S100 proteins,
• MeSH
• Biomarkers MeSH
• Adult MeSH
• Cells, Cultured MeSH
• Middle Aged MeSH
• Humans MeSH
• Inflammation Mediators metabolism   MeSH
• Disease Progression * MeSH
• S100 Proteins metabolism   MeSH
• Cross-Sectional Studies MeSH
• Arthritis, Rheumatoid diagnosis   metabolism   MeSH
• Aged MeSH
• Synovial Fluid metabolism   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Biomarkers MeSH
• Inflammation Mediators MeSH
• S100 Proteins MeSH
• S100A11 protein, human MeSH Browser

BACKGROUND: The efficacy of exercise therapy for ankylosing spondylitis (AS) is well-documented, but dearth of information is for non-radiographic axial spondyloarthritis (nr-axSpA). Biomarkers like serum calprotectin, interleukins IL-6, IL-17 and tumour necrosis factor (TNF)-α may reflect the disease activity of axial spondyloarthritis (axSpA). In this study, we investigated clinical and laboratory parameters of both axSpA subgroups in response to intensive physical exercise. METHODS: Altogether, 46 patients with axSpA, characterised according to the Assessment of SpondyloArthritis International Society criteria as having nr-axSpA or AS underwent 6-month exercise programme. Clinical outcomes of disease activity, Bath AS Disease Activity Index (BASDAI), AS Disease Activity Index (ASDAS-CRP), mobility, Bath AS Metrology Index (BASMI) and function, Bath AS Functional Index (BASFI) were evaluated at baseline and at the end of the exercise programme. Serum IL-6 and IL-17, TNF-α and calprotectin were measured via ELISA. The clinical and laboratory data of 29 control axSpA patients were used for the evaluation of the results. RESULTS: In all axSpA patients, the ASDAS-CRP (2.10 ± 0.12 to 1.84 ± 0.11, p <0.01) and BASMI (1.28 ± 0.14 to 0.66 ± 0.84, p <0.0001) improved after 6 months of exercise therapy. There was a significant improvement in the ASDAS-CRP in the nr-axSpA subgroup (2.01 ± 0.19 to 1.73 ± 0.16, p <0.05) and in the BASMI in both, the nr-axSpA and the AS subgroups (1.09 ± 0.12 to 0.47 ± 0.08, p <0.0001 and 1.43 ± 0.24 to 0.82 ± 0.23, p <0.0001, respectively). Both, ASDAS-CRP and BASDAI, were significantly improved in the exercise axSpA group compared to the control axSpA group (mean -0.26 vs. -0.13 and -0.49 vs. 0.12, respectively, all p <0.05). Only calprotectin was significantly reduced after the exercise programme in nr-axSpA and AS patients (from 2379.0 ± 243.20 to 1779.0 ± 138.30 μg/mL and from 2430.0 ± 269.70 to 1816.0 ± 148.20 μg/mL, respectively, all p <0.01). The change in calprotectin was more profound in the axSpA intervention group (mean -604.56) than in the control axSpA (mean -149.28, p <0.05). CONCLUSION: This study demonstrated similar efficacy for an intensive exercise programme in both nr-axSpA and AS patients. A significant decrease in serum calprotectin levels in both subgroups of axSpA patients after the exercise programme reflected an improvement in the disease activity and spinal mobility.

• Keywords
• Ankylosing spondylitis, Axial spondyloarthritis, Calprotectin, Disease activity, Exercise programme, Non-radiographic,
• MeSH
• Spondylitis, Ankylosing blood   rehabilitation   MeSH
• Biomarkers blood   MeSH
• Adult MeSH
• Enzyme-Linked Immunosorbent Assay MeSH
• Immunoassay MeSH
• Leukocyte L1 Antigen Complex blood   MeSH
• Humans MeSH
• Spondylarthritis blood   rehabilitation   MeSH
• Exercise Therapy methods   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Clinical Trial MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Biomarkers MeSH
• Leukocyte L1 Antigen Complex MeSH

OBJECTIVE: Clinical remission in some patients with rheumatoid arthritis (RA) may be associated with ongoing synovial inflammation that is not always detectable on clinical examination or reflected by laboratory tests but can be visualized by musculoskeletal ultrasound. The goal of our study was to determine the levels of serum calprotectin, a major leukocyte protein, in patients with RA in clinical remission and to investigate the ability of serum calprotectin levels to distinguish patients in ultrasound-defined remission from those with residual ultrasound subclinical inflammation. METHODS: Seventy RA patients in clinical remission underwent clinical and ultrasound examination. Ultrasound examination was performed according to the German US7 score. Ultrasound remission was defined as grey scale (GS) range 0-1 and power Doppler (PD) range 0. The levels of serum calprotectin and C-reactive protein (CRP) were determined. The discriminatory capacity of calprotectin and CRP in detecting residual ultrasound inflammation was assessed using ROC curves. RESULTS: The total number of patients fulfilling the DAS28-ESR, DAS28-CRP, SDAI and CDAI remission criteria was 58, 67, 32 and 31, respectively. Residual synovial inflammation was found in 58-67% of the patients who fulfilled at least one set of clinical remission criteria. Calprotectin levels were significantly higher in patients with residual synovial inflammation than in those with ultrasound-defined remission (mean 2.5±1.3 vs. 1.7±0.8 μg/mL, p<0.005). Using ultrasound-defined remission criteria, calprotectin had an AUC of 0.692, p<0.05 using DAS28-ESR remission criteria and an AUC of 0.712, p<0.005 using DAS28-CRP remission criteria. Calprotectin correctly distinguished ultrasound remission from subclinical activity in 70% of patients. CRP (AUC DAS28-ESR = 0.494, p = NS; AUC DAS28-CRP = 0.498, p = NS) had lower and insignificant discriminatory capacity. CONCLUSION: The present study demonstrates the potential of calprotectin to distinguish RA patients in both clinical and ultrasound-defined remission from patients in clinical remission but with residual subclinical disease activity.

• MeSH
• C-Reactive Protein analysis   MeSH
• Adult MeSH
• Leukocyte L1 Antigen Complex blood   MeSH
• Middle Aged MeSH
• Humans MeSH
• Arthritis, Rheumatoid blood   diagnostic imaging   MeSH
• Neoplasm, Residual MeSH
• Aged MeSH
• Ultrasonography MeSH
• Inflammation blood   diagnostic imaging   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• C-Reactive Protein MeSH
• Leukocyte L1 Antigen Complex MeSH

INTRODUCTION: Calprotectin, a heterodimeric complex of S100A8/9 (MRP8/14), has been proposed as an important serum biomarker that reflects disease activity and structural joint damage in rheumatoid arthritis (RA). The objective of this cross-sectional study was to test the hypothesis that calprotectin is associated with clinical and ultrasound-determined disease activity in patients with RA. METHODS: A total of 37 patients with RA (including 24 females, a mean disease duration of 20 months) underwent a clinical examination and 7-joint ultrasound score (German US-7) of the clinically dominant hand and foot to assess synovitis by grey-scale (GS) and synovial vascularity by power Doppler (PD) ultrasound using semiquantitative 0-3 grading. The levels of serum calprotectin and C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were determined at the time of the ultrasound assessment. We analysed the relationship between serum calprotectin level, traditional inflammatory markers, and ultrasound-determined synovitis. RESULTS: The levels of serum calprotectin were significantly correlated with swollen joint count (r = 0.465, p < 0.005), DAS28-ESR (r = 0.430, p < 0.01), ESR (r = 0.370, p < 0.05) and, in particular, CRP (r = 0.629, p < 0.001). Calprotectin was significantly associated with GS (r = 0.359, p < 0.05) and PD synovitis scores (r = 0.497, p < 0.005). Using multivariate regression analysis, calprotectin, adjusted for age and sex, was a better predictor of PD synovitis score (R(2) = 0.765, p < 0.001) than CRP (R(2) = 0.496, p < 0.001). CONCLUSIONS: The serum levels of calprotectin are significantly associated with clinical, laboratory and ultrasound assessments of RA disease activity. These results suggest that calprotectin might be superior to CRP for monitoring ultrasound-determined synovial inflammation in RA patients.

• MeSH
• Biomarkers blood   MeSH
• C-Reactive Protein metabolism   MeSH
• Adult MeSH
• Blood Sedimentation MeSH
• Leukocyte L1 Antigen Complex blood   MeSH
• Middle Aged MeSH
• Humans MeSH
• Predictive Value of Tests MeSH
• Prognosis MeSH
• Cross-Sectional Studies MeSH
• Reproducibility of Results MeSH
• Arthritis, Rheumatoid blood   diagnosis   diagnostic imaging   MeSH
• Aged MeSH
• Sensitivity and Specificity MeSH
• Severity of Illness Index MeSH
• Synovitis blood   diagnosis   diagnostic imaging   MeSH
• Ultrasonography, Doppler methods   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Biomarkers MeSH
• C-Reactive Protein MeSH
• Leukocyte L1 Antigen Complex MeSH