Umeå University's logo

Objectives: There is a need for more specific biomarkers to diagnose and predict disease course in patients with axial spondyloarthritis (axSpA). This study aimed to study immunological plasma biomarkers at different time-points in radiographic (r)-axSpA patients overall and stratified by sex and compare these biomarker patterns in r-axSpA patients concerning disease phenotypes and disease activity.

Methods: Plasma samples were analysed from r-axSpA patients at and prior (Pre-Backbone) inclusion in the Backbone study. Interferon gamma, interleukin-10, -17A, -17F, -22, -23, -6, MCP-1, TNF-alpha, VEGF-A, MIF, IgA anti-CD74, zonulin, ESR, hsCRP, white blood cell count, and blood lipids were measured.

Results: Biomarker pattern discriminated significantly between r-axSpA patients in Backbone and Pre-Backbone compared with controls. When stratifying by sex, it was possible to discriminate between male and female r-axSpA patients in Backbone vs controls and between male r-axSpA patients in pre-Backbone and controls. In Backbone, markers with high discriminative capacity were MIF, IgA anti-CD74, and MCP-1. In Pre-Backbone, IL-6, TNF-alpha, MIF, triglycerides, cholesterol, IL-10, and zonulin displayed high discriminative capacity.

Conclusion: Based on their temporal pattern and mutual relationship, we suggest studying MIF, IgA anti-CD74, and MCP-1 in depth, at more time points, to further elucidate disease-driving mechanisms in this complex disease.

Objective: There is an increased risk for cardiovascular disease (CVD) in patients with radiographic axial spondyloarthritis (r-axSpA). In this cross-sectional study, we aimed to, overall and stratified by sex, (i) compare ultrasound derived carotid intima media thickness (cIMT), between patients and controls, and (ii) investigate associations between cIMT, clinical disease activity and inflammation-related laboratory markers in patients with r-axSpA.

Method: In total, 155 patients diagnosed with r-axSpA using the modified New York criteria and 400 controls were included. Bilateral carotid ultrasound, laboratory testing, and questionaries were acquired. Disease-specific assessments were carried out for patients. Linear regression analysis was used to assess associations.

Results: Linear regression analyses showed that patients with r-axSpA had increased mean cIMT compared to controls (mean ± SD, 0.8 ± 0.1 mm vs 0.7± 0.1 mm, respectively, unstandardized β (95% CI) -0.076 (-0.10, -0.052), P < 0.001) adjusted for smoking status and age. Linear regression analyses for patients with r-axSpA showed that only males presented significant associations between cIMT and inflammation-related laboratory markers, white blood cell (WBC) count (mean ± SD, 6.8 ± 1.6 10⁹/L) and monocytes (0.6 ± 0.2 10⁹/L); WBC count (unstandardized β (95% CI) 0.019 (0.0065, 0.031), P = 0.003, R² = 0.57) and monocytes (0.13 (0.0047, 0.26), P = 0.041, R² = 0.55), adjusted for age, smoking status, body mass index, hypertension, dyslipidemia, diabetes mellitus, ASDAS-CRP, and treatment with DMARDs and glucocorticoids. No significant association was found between cIMT and clinical disease activity assessed by ASDAS-CRP.

Conclusion: Patients with r-axSpA had significantly increased cIMT compared to controls. In male patients, higher WBC and monocyte count were associated with an increase in cIMT suggesting the role of inflammation in the development of atherosclerosis. 

The purpose of this study was to study CD4+CXCR5+ T follicular helper (TFH) cells, CD27+CD38+ plasmablasts and CD27+CD38− memory B cells, as well as disease-related factors in patients with ankylosing spondylitis (AS) from northern Sweden. Peripheral blood mononuclear cells (PBMC) from 50 patients with AS (mean age 52 ± 9 years, 66% men, 100% HLA-B27 positive) and 50 pairwise matched blood donor controls (mean age 54 ± 9 years, 66% men) were stained with antibodies for CD27, CD38, CD19, CD3, CD4 and CXCR5 markers and analysed by flow cytometry. Patients with AS were examined with spinal x-ray for radiographic alterations (mSASSS), and plasma levels of C-reactive protein, erythrocyte sedimentation rate, as well as selected proinflammatory and regulatory cytokines were determined. Physical mobility, function and disease activity were registered by BASMI, BASFI and ASDAS-CRP, BASDAI, respectively. Comparing AS patients and controls pairwise, we observed a 56% reduction of TFH cells in PBMCs from AS patients (P =.000008). Furthermore, a 20%-30% reduction in plasmablasts and B memory cells (P ≤.002 and P ≤.007, respectively) was observed. In female patients, negative correlations between ESR and TFH, plasmablasts and B memory cells were observed; Rs = −0.551, P ≤.02; Rs = −0.476, P ≤.05 and Rs = −0.522, P ≤.03, respectively. In addition, positive correlations between the regulatory cytokine IL-10 and the proportion of B cells, IL-22, and the proportion of plasmablasts as well as a negative correlation between levels of the proinflammatory cytokine IL-6 and TFH were detected. Our observations indicate a role of an aberrant humoral immune response related to inflammation in AS.

Objective: Antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV) is a chronic relapsing condition with unknown etiology. To gain insight into the molecular processes underlying the disease, we examined biomarkers in blood samples collected prior to symptom onset.

Methods: The National Patient Register and Cause of Death register were searched for AAV-related International Classification of Diseases, Ninth Revision and Tenth Revision codes and linked to the registers from 5 biobanks. Eighty-five AAV patients with samples predating symptom onset of AAV were identified. For each case of AAV, 2 matched controls were included. Proteinase 3 (PR3)–ANCA and myeloperoxidase (MPO)–ANCA expression levels were analyzed using enzyme-linked immunosorbent assays. Using an Olink Inflammation panel, 73 of 92 proteins were included after quality control. Data were replicated in a second cohort of 48 presymptomatic individuals and 96 controls.

Results: Of the 20 proteins with the lowest P values in the original cohort, 7 were replicated in the second cohort and 5 proteins were found to be significant between the groups in a meta-analysis. Eleven different pathways were identified in network enrichment analyses and were found to be significant in both cohorts. Stratification of samples obtained ≤5 years before symptom onset showed significant levels of CCL23, vascular endothelial growth factor A, and hepatocyte growth factor, which were also increased at borderline significant levels in the replication cohort (interleukin-6 was found to be significantly increased in the replication cohort). In presymptomatic AAV patients, 6 proteins were associated with MPO-ANCA positivity, and 7 proteins were associated with PR3-ANCA positivity.

Conclusion: To our knowledge, this is the first study to identify protein markers preceding symptom onset in AAV patients. These findings set the stage for further research into the underlying cellular and molecular mechanisms in the pathogenesis of AAV and the diversification of patients into PR3-ANCA+ and MPO-ANCA+ subphenotypes. (Figure presented.).

B cells have been shown to be essential for Type 1 diabetes development in the non-obese diabetic mouse, where their contribution as antigen presenting cells has been emphasised. Other important functions for B cells include surface capture of immunoglobulins and transportation of immune complexes, with subsequent endocytosis, antigen processing and antigen presentation. We have previously demonstrated that NOD B cells capture IgM and IgG immune complexes through an unknown surface molecule. In this study, we revealed the presumptive immunoglobulin-binding molecule to be HSC70. Moreover, we detected increased levels of HSC70 on NOD B cells. HSC70 has been shown to play a role in antigen processing and presentation as well as being important in several autoimmune diseases, including rheumatoid arthritis and systemic lupus erythematosus. Due to its protein stabilising properties, increased HSC70 could contribute to enhanced self-antigen collection and presentation and thereby contribute to the development of Type 1 diabetes.

Ankylosing spondylitis (AS) is an autoimmune disease affecting parts of the skeletal structure in particular. Previously increased levels of the inflammatory cell types Th17, Th22, Tc17 and Tc22 cells have been shown to be associated with AS. Here, we analysed the levels of inflammatory T cell subsets, related cytokines and clinical characteristics of AS patients vs controls from northern Sweden. Peripheral blood mononuclear cells (PBMCs) obtained from 50 AS patients and 50 matched controls were short term stimulated with PMA/Ionomycin, stained and analysed by flow cytometry. Plasma levels of Interleukin (IL)-17, IL-22, IL-10 as well as clinically relevant markers were determined. Compared to male controls, male AS patients showed 1.5- to 2-fold increases of Th17 (P = .013), Th22 (P = .003) and Tc22 (P = .024) among CD45+CD3+ lymphocytes. Plasma IL-22 levels correlated with the Tc17 proportion in male patients (R_s = 0.499, P = .003) and plasma IL-10 levels were inversely correlated with Tc17 among all patients (R_s = −0.276, P = .05). Male patients with syndesmophytes showed significantly higher Th17 proportions (P = .038). In female AS patients, Tc22 was negatively correlated with C-reactive protein (high sensitivity) (hsCRP) (R_s = −0.573, P = .016). We confirmed increased proportions of inflammatory T cells and correlations with relevant cytokines from male AS patients. The correlation between Th17 and syndesmophytes supports a role of Th17 in the pathogenic process.

OBJECTIVES: Antibodies against anti-CD74 are related to axial spondyloarthritis (axSpA). The objectives were (i) to study IgA anti-CD74 in radiographic (r)-axSpA patients in the Backbone cohort and to calculate the sensitivity and specificity of anti-CD74, (ii) to study the fluctuation of IgA anti-CD74 levels in prospectively collected samples, and (iii) to explore the relation between IgA anti-CD74 and radiographic spinal changes.

METHODS: IgA anti-CD74 was analysed by ELISA in 155 patients with r-axSpA and age- and sex-matched controls. BASDAI, ASDAS, BASFI and BASMI were assessed and spinal radiographs were scored for r-axSpA-related changes with mSASSS. Previously donated samples, before inclusion in the Backbone study, were identified in the Medical Biobank of Northern Sweden.

RESULTS: A total of 155 patients comprising 69% men and 31% women, age [mean (s.d.)] 55.5 (11.4) years and 152 (98.1%) HLA-B27 positive, were included. The plasma level of IgA anti-CD74 was significantly higher in the patients [median (interquartile range), 12.9 (7.9-17.9) U/ml] compared with controls [10.9 (7.2-14.6) U/ml, P = 0.003]. IgA anti-CD74 was above the cut-off level of 20 U/ml in 36/155 (23.2%) patients and in 15/151 (9.9%) controls (P = 0.002). Multivariable logistic regression analyses revealed ≥1 syndesmophyte associated with IgA anti-CD74 (odds ratio 5.64; 95% CI: 1.02, 35.58; P = 0.048) adjusted for hsCRP, smoking, BMI, sex and age. No distinct pattern of IgA anti-CD74 over time was revealed.

CONCLUSION: Plasma levels of IgA anti-CD74 were increased in r-axSpA and independently associated with radiographic spinal changes, which suggests that IgA anti-CD74 could play a role in the pathogenies of r-axSpA.

Objectives: Patients with rheumatoid arthritis (RA) have an accelerated progression of atherosclerosis. The aims of this study were to study the associations between subsets of T-cells, subclinical atherosclerosis assessed by intima-media thickness (IMT) and serological status for CMV in patients with RA.

Methods: Patients with new-onset RA (n=79), aged ≤60 years at diagnosis, were included in a prospective study of atherosclerosis. Controls matched for age and sex were also included (n=44). Ultrasound measurement of IMT in the common carotid artery was undertaken at inclusion (T0), after 1.5 years (T1.5) and after 11 years (T11). At T11, flow-cytometry analysis was undertaken to investigate subsets of T-cells. Serological analysis for CMV was undertaken from samples collected at T0.

Results: At T0, 66% of the patients and controls were CMV immunoglobulin G-positive. CMV-IgG positive patients had a significantly more rapid increase in IMT at T1.5, compared with controls and CMV-IgG negative patients. CMV-IgG positive patients had a significantly higher percentage of T-cells lacking CD28 (both CD4+CD28null and CD8+CD28null T-cells) than CMV-IgG negative patients. Increased levels of CD4+CD28null and CD8+CD28null T-cells were significantly associated with IMT at T11, adjusted for systolic blood pressure. CX3CR1 was expressed in CD4+ and CD8+ CD28null T-cells, but CX3CR1 per se was not associated with increased IMT.

Conclusions: Presence of CMV IgG-antibodies in patients with RA is associated with altered T-cell-populations and an increased burden of atherosclerosis. A possible protective effect of antiviral treatment in CMV-positive patients with new-onset RA should be considered.

OBJECTIVE: Recent studies have demonstrated an altered expression of certain microRNAs in patients with rheumatoid arthritis (RA) as well as their first-degree relatives (FDRs) compared to healthy controls (HCs), suggesting a role of microRNA in the progression of the disease. To corroborate this, a set of well-characterized RA families originating from northern Sweden were analyzed for differential expression of a selected set of microRNAs.

METHOD: MicroRNA was isolated from frozen peripheral blood cells obtained from 21 different families and included 26 RA patients, 22 FDRs, and 21 HCs. Expression of the selected microRNAs miR-22-3p, miR-26b-5p, miR-34a-3p, miR-103a-3p, miR-142-3p, miR-146a-5p, miR-155, miR-346, and miR-451a was determined by a two-step quantitative real-time polymerase chain reaction (qRT-PCR). Statistical analysis including clinical variables was applied.

RESULTS: Out of the nine selected microRNAs that previously have been linked to RA, we confirmed four after adjusting for age and gender, i.e., miR-22-3p (p = 0.020), miR-26b-5p (p = 0.018), miR-142-3p (p = 0.005), and miR-155 (p = 0.033). Moreover, a significant trend with an intermediate microRNA expression in FDR was observed for the same four microRNAs. In addition, analysis of the effect of corticosteroid use showed modulation of miR-103a-3p expression.

CONCLUSIONS: We confirm that microRNAs seem to be involved in the development of RA, and that the expression pattern in FDR is partly overlapping with RA patients. The contribution of single microRNAs in relation to the complex network including all microRNAs and other molecules is still to be revealed. Key Points • Expression levels of miR-22-3p, miR-26b-5p, miR-142-3p, and miR-155 were significantly altered in RA patients compared to those in controls. • In first-degree relatives, a significant trend with an intermediate microRNA expression in FDR was observed for the same four microRNAs.