Revisiting Circulating Extracellular Matrix Fragments as Disease Markers in Myelofibrosis and Related Neoplasms.

Philadelphia chromosome-negative chronic myeloproliferative neoplasms (MPNs) arise due to acquired somatic driver mutations in stem cells and develop over 10-30 years from the earliest cancer stages (essential thrombocythemia, polycythemia vera) towards the advanced myelofibrosis stage with bone marrow failure. The JAK2V617F mutation is the most prevalent driver mutation. Chronic inflammation is considered to be a major pathogenetic player, both as a trigger of MPN development and as a driver of disease progression. Chronic inflammation in MPNs is characterized by persistent connective tissue remodeling, which leads to organ dysfunction and ultimately, organ failure, due to excessive accumulation of extracellular matrix (ECM). Considering that MPNs are acquired clonal stem cell diseases developing in an inflammatory microenvironment in which the hematopoietic cell populations are progressively replaced by stromal proliferation-"a wound that never heals"-we herein aim to provide a comprehensive review of previous promising research in the field of circulating ECM fragments in the diagnosis, treatment and monitoring of MPNs. We address the rationales and highlight new perspectives for the use of circulating ECM protein fragments as biologically plausible, noninvasive disease markers in the management of MPNs.

Lymphocyte activation gene 3 is increased and affects cytokine production in rheumatoid arthritis.

BACKGROUND: Lymphocyte activation gene-3 (LAG-3) inhibits T cell activation and interferes with the immune response by binding to MHC-II. As antigen presentation is central in rheumatoid arthritis (RA) pathogenesis, we studied aspects of LAG-3 as a serological marker and mediator in the pathogenesis of RA. Since Galectin-3 (Gal-3) is described as an additional binding partner for LAG-3, we also aimed to study the functional importance of this interaction. METHODS: Plasma levels of soluble (s) LAG-3 were measured in early RA patients (eRA, n = 99) at baseline and after 12 months on a treat-to-target protocol, in self-reportedly healthy controls (HC, n = 32), and in paired plasma and synovial fluid (SF) from chronic RA patients (cRA, n = 38). Peripheral blood mononuclear cells (PBMCs) and synovial fluid mononuclear cells (SFMCs) were examined for LAG-3 expression by flow cytometry. The binding and functional outcomes of LAG-3 and Gal-3 interaction were assessed with surface plasmon resonance (SPR) and in cell cultures using rh-LAG3, an antagonistic LAG-3 antibody and a Gal-3 inhibitor. RESULTS: Baseline sLAG-3 in the plasma was increased in eRA compared to HC and remained significantly elevated throughout 12 months of treatment. A high level of sLAG-3 at baseline was associated with the presence of IgM-RF and anti-CCP as well as radiographic progression. In cRA, sLAG-3 was significantly increased in SF compared with plasma, and LAG-3 was primarily expressed by activated T cells in SFMCs compared to PBMCs. Adding recombinant human LAG-3 to RA cell cultures resulted in decreased cytokine secretion, whereas blocking LAG-3 with an antagonistic antibody resulted in increased cytokine secretion. By SPR, we found a dose-dependent binding between LAG-3 and Gal-3. However, inhibiting Gal-3 in cultures did not further change cytokine production. CONCLUSIONS: sLAG-3 in the plasma and synovial fluid is increased in both early and chronic RA patients, particularly in the inflamed joint. High levels of sLAG-3 are associated with autoantibody seropositivity and radiographic progression in eRA, and LAG-3 plays a biologically active role in cRA by decreasing inflammatory cytokine production. This functional outcome is not affected by Gal-3 interference. Our results suggest that LAG-3 is a faceted regulator of inflammation in early and chronic RA.

Serological markers of basement membrane collagen type IV and laminin are increased in systemic lupus erythematosus but differentially expressed in patients with previous cardiovascular events.

OBJECTIVES: To assess basement membrane remodelling in systemic lupus erythematosus (SLE) by studying serum levels of type IV collagen (C4M) and laminin (LG1M) fragments and their association with disease profile. METHODS: One hundred and six SLE patients without and 20 with previous cardiovascular events were included. One hundred and twenty male and female blood donors served as controls. Disease activity score (SLEDAI-2K) and cumulated damage index (SLICC-DI) were calculated. Coronary artery calcification (CAC) was studied by CT scan. Carotid intima-media thickness (IMT) was measured by ultrasound. C4M and LG1M were quantified by ELISAs. RESULTS: Serum levels of LG1M and C4M were significantly increased in the entire SLE cohort, median (IQR) 15.8 (26.16) ng/ml vs. 5.5 (5.8) ng/ml (±9.4), p<0.0001 and 31.3 (20.0) vs. 21.6 (9.2) ng/ml, p<0.0001. C4M and LG1M were mutually interrelated in patients and controls, r=0.44 (p<0.0001) and r=0.42 (p<0.0001). LG1M was significantly higher in patients with previous cardiovascular events (CVE), 27.2 (30.8) vs. 14.1 (21.4) p<0.03, while C4M did not differ between these subsets. LG1M, but not C4M, was borderline higher in anti-phospholipid antibody-positive patients vs. negatives (p=0.08). There was a weak correlation between LG1M and SLICC-DI, r=0.22 (p=0.01), but no associations between these markers and criterial lupus manifestations or asymptomatic atherosclerosis. CONCLUSIONS: These findings indicate that remodelling of collagen type IV and laminin is increased in SLE unrelated to disease activity, presumably reflecting clinically silent disease progression. The selective association of increased LG1M and cardiovascular events may represent a distinctive aspect of SLE-related vessel wall repair.

Plasma levels of multiple cardiovascular- and inflammation-related proteins analysed for associations with disease activity and anti-cyclic citrullinated peptide status in active early rheumatoid arthritis.

OBJECTIVES: To compare plasma levels of 92 cardiovascular- and inflammation-related proteins (CIRPs) and to analyse for associations with anti-cyclic citrullinated peptide (anti-CCP) status and disease activity in early and treatment-naive rheumatoid arthritis (RA). METHODS: Olink CVD-III-panel was used to measure 92 CIRP plasma levels in 180 early, treatment-naive, and highly inflamed RA patients from the OPERA trial. CIRP plasma levels as well as correlation between CIRP plasma levels and RA disease activity were compared between anti-CCP groups. CIRP level-based hierarchical cluster analysis was performed in each anti-CCP group separately. RESULTS: The study included 117 anti-CCP-positive and 63 anti-CCP-negative RA patients. Among the 92 CIRPs measured, the levels of chitotriosidase-1 (CHIT1) and tyrosine-protein-phosphatase non-receptor-type substrate-1 (SHPS-1) were increased and those of metalloproteinase inhibitor-4 (TIMP-4) decreased in the anti-CCP-negative group compared to anti-CCP-positive group. The strongest associations with RA disease activity were found for interleukin-2 receptor-subunit-alpha (IL2-RA) and E-selectin levels in the anti-CCP-negative group and for C-C-motif chemokine-16 levels (CCL16) in the anti-CCP-positive group. None of the differences passed the Hochberg sequential multiplicity test, however, the CIPRs were interacting and thus the prerequisites of the Hochberg procedure were not fulfilled. CIRP level-based cluster analysis identified two patient clusters in both anti-CCP groups. Demographic and clinical characteristics were similar in the two clusters for each anti-CCP group. CONCLUSIONS: In active and early RA, the findings regarding CHIT1, SHPS-1 TIMP-4, IL2-RA, E-selectin, and CCL16 differed between the two anti-CCP groups. In addition, we identified two patient clusters that were independent of the anti-CCP status.

Increased Galectin-9 Levels Correlate with Disease Activity in Patients with DMARD-Naïve Rheumatoid Arthritis and Modulate the Secretion of MCP-1 and IL-6 from Synovial Fibroblasts.

Background: Fibroblast-like synoviocytes (FLSs) are essential mediators in the expansive growth and invasiveness of rheumatoid synovitis, and patients with a fibroblastic-rich pauci-immune pathotype respond poorly to currently approved antirheumatic drugs. Galectin-9 (Gal-9) has been reported to directly modulate rheumatoid arthritis (RA) FLSs and to hold both pro- and anti-inflammatory properties. The objective of this study was to evaluate clinical and pathogenic aspects of Gal-9 in RA, combining national patient cohorts and cellular models. Methods: Soluble Gal-9 was measured in plasma from patients with newly diagnosed, treatment-naïve RA (n = 98). The disease activity score 28-joint count C-reactive protein (DAS28CRP) and total Sharp score were used to evaluate the disease course serially over a two-year period. Plasma and synovial fluid samples were examined for soluble Gal-9 in patients with established RA (n = 18). A protein array was established to identify Gal-9 binding partners in the extracellular matrix (ECM). Synovial fluid mononuclear cells (SFMCs), harvested from RA patients, were used to obtain synovial-fluid derived FLSs (SF-FLSs) (n = 7). FLSs from patients suffering from knee Osteoarthritis (OA) were collected from patients when undergoing joint replacement surgery (n = 5). Monocultures of SF-FLSs (n = 6) and autologous co-cultures of SF-FLSs and peripheral blood mononuclear cells (PBMCs) were cultured with and without a neutralizing anti-Gal-9 antibody (n = 7). The mono- and co-cultures were subsequently analyzed by flow cytometry, MTT assay, and ELISA. Results: Patients with early and established RA had persistently increased plasma levels of Gal-9 compared with healthy controls (HC). The plasma levels of Gal-9 were associated with disease activity and remained unaffected when adding a TNF-inhibitor to their standard treatment. Gal-9 levels were elevated in the synovial fluid of established RA patients with advanced disease, compared with corresponding plasma samples. Gal-9 adhered to fibronectin, laminin and thrombospondin, while not to interstitial collagens in the ECM protein array. In vitro, a neutralizing Gal-9 antibody decreased MCP-1 and IL-6 production from both RA FLSs and OA FLSs. In co-cultures of autologous RA FLSs and PBMCs, the neutralization of Gal-9 also decreased MCP-1 and IL-6 production, without affecting the proportion of inflammatory FLSs. Conclusions: In RA, pretreatment plasma Gal-9 levels in early RA were increased and correlated with clinical disease activity. Gal-9 levels remained increased despite a significant reduction in the disease activity score in patients with early RA. The in vitro neutralization of Gal-9 decreased both MCP-1 and IL-6 production in an inflammatory subset of RA FLSs. Collectively these findings indicate that the persistent overexpression of Gal-9 in RA may modulate synovial FLS activities and could be involved in the maintenance of subclinical disease activity in RA.

T-cell immunoglobulin and mucin domain 3 is upregulated in rheumatoid arthritis, but insufficient in controlling inflammation.

OBJECTIVES: Rheumatoid arthritis (RA) is a chronic autoimmune disease, that involves both pro- and anti-inflammatory mechanisms. The purpose of the present study is to investigate T-cell immunoglobulin and mucin domain 3 (Tim-3) in RA. METHODS: Plasma levels of soluble (s) Tim-3 in early RA (n=98), were followed, to evaluate association with treatment and disease activity, acquired from a prospective collected biobank (clinicaltrials.gov (NCT00660647)). We also investigate the influence of Tim-3 on spontaneous cytokine production in synovial fluid mononuclear cells (SFMC) from RA patients after addition of neutralizing anti-Tim-3's antibodies, either alone or in combination with neutralizing anti-Programmed Cell death protein 1 (PD-1) antibodies. RESULTS: Long-time stimulated CD4 T-cells expressed high levels of Tim-3, but tended to decrease their PD-1 expression. Tim-3 expression was exclusively seen co-expressed with PD-1 by CD3, CD4, CD45RO positive cells in the inflamed RA joint. Addition of neutralizing Tim-3 antibodies increased the secretion of IFNγ and MCP-1, in SFMC cultures from RA. Whereas neutralizing anti-PD-1 antibodies showed a broader impact on cytokine production. Finally, we observed that soluble Tim-3 is increased in plasma and is associated with disease activity in early RA. CONCLUSION: Taken together, our findings indicate disease-suppressive functions of Tim-3 in RA.

The Programmed Death-1 Pathway Counter-Regulates Inflammation-Induced Osteoclast Activity in Clinical and Experimental Settings.

Objective: The programmed death-1 (PD-1) pathway is essential for maintaining self-tolerance and plays an important role in autoimmunity, including rheumatoid arthritis (RA). Here, we investigated how membrane-bound and soluble (s)PD-1 influence bone homeostasis during chronic inflammation, exemplified in RA. Methods: Bone mineral density and bone microstructure were examined in PD-1 and PD-L1 knockout (KO) mice and compared with wild-type (WT) mice. Receptor activator of nuclear factor kappa-B ligand (RANKL) was measured in serum, and the expression examined on activated bone marrow cells. Osteoclast formation was examined in cells from murine spleen and bone marrow and from human synovial fluid cells. sPD-1 was measured in chronic and early (e)RA patients and correlated to markers of disease activity and radiographic scores. Results: PD-1 and PD-L1 KO mice showed signs of osteoporosis. This was supported by a significantly reduced trabecular bone volume fraction and deteriorated microstructure, as well as increased osteoclast formation and an increased RANKL/OPG ratio. The recombinant form of sPD-1 decreased osteoclast formation in vitro, but was closely associated with disease activity markers in eRA patients. Sustained elevated sPD-1 levels indicated ongoing inflammation and were associated with increased radiographic progression. Conclusion: The PD-1 pathway is closely associated with bone homeostasis, and lacking members of this pathway causes a deteriorated bone structure. The immunological balance in the microenvironment determines how the PD-1 pathway regulates osteoclast formation. In eRA patients, sPD-1 may serve as a biomarker, reflecting residual but clinically silent disease activity and radiographic progression.

CXCL13 predicts long-term radiographic status in early rheumatoid arthritis.

OBJECTIVES: Identification of RA patients at a high risk of joint destruction remains challenging. The C-X-C motif chemokine 13 (CXCL13) has previously been suggested as a marker of disease activity in RA. Here, we investigate the potential of plasma CXCL13 as a marker of long-term radiographic status and progression. METHODS: CXCL13 was measured in plasma from treatment-naïve RA patients (n = 158) with an 11-year follow-up. At baseline, clinical and biochemical DASs were obtained; among these CRP, ESR, DAS in 28 joints with CRP (DAS28CRP), number of swollen joints (SJC28) and radiographic status, evaluated by total Sharp score (TSS). Age- and gender-matched healthy controls (HCs) were included. RESULTS: CXCL13 was significantly increased at baseline and decreased during treatment; however, it was not reduced to the level in HCs. At baseline, CXCL13 was associated with both CRP and ESR, but not with other markers of disease activity. Baseline CXCL13 was correlated with both TSS and radiographic progression (ΔTSS) at 11 years. With an 89% probability, levels of CXCL13 above 85 pg/ml predicted the risk of a TSS of 5 or above, after 11 years of treatment. Compared with CRP, DAS28CRP, SJC28 and ACPA status, CXCL13 was superior in predicting 11-year joint destruction. CONCLUSION: In early RA, one single measurement of plasma CXCL13 at baseline is superior to currently used clinical and serological disease markers in the prediction of long-term radiographic status and progression.

Circadian, Week-to-Week, and Physical Exercise-Induced Variation of Serum Microfibrillar-Associated Protein 4.

Serum microfibrillar-associated protein 4 (sMFAP4) has been investigated as a biomarker for various diseases and is demonstrated to show significant gradual increase with severity of liver fibrosis. Ideal biomarkers used for disease diagnosis or prognosis should display deviating levels in affected individuals only and be robust to factors unrelated to the disease. Here we show the impact of normal physiological variation of sMFAP4 by characterizing the circadian variation, week-to-week variation, and physical exercise-induced levels. Serum samples from 3 groups of healthy volunteers were drawn: 7 times during a 24-hour period, 5 times during a 3-week period, and before and after a standardized physical exercise challenge. sMFAP4 was determined by AlphaLISA. Statistical analysis was performed using mixed effects modeling of repeated measurements. Circadian variation of sMFAP4 was demonstrated, with time of peak and nadir values depending on age and gender. For males, the peak values were observed during nighttime whereas for females, peak values were observed in the morning. Individual sMFAP4 levels remained stable over a period of 3 weeks and physical exercise inferred a mild negative influence. In conclusion, the circadian sMFAP4 variation was significant, and the levels could be influenced by physical activity. However, these variations were of limited magnitude relative to previously observed disease-induced levels in support of the biomarker potential of sMFAP4.

Altered Antibody Response to Epstein-Barr Virus in Patients With Rheumatoid Arthritis and Healthy Subjects Predisposed to the Disease. A Twin Study.

Objectives: To study Epstein-Barr virus (EBV) antibody patterns in twin individuals with rheumatoid arthritis (RA) and their healthy co-twins, and to determine the heritability of antibody responses against the EBV encoded EBNA1 protein. Methods: Isotypes of EBNA1 antibodies were measured in 137 RA affected- and 150 healthy twin pairs. We estimated the effect of RA and RA predisposition, anti-citrullinated antibodies (ACPA), IgM rheumatoid factor (RF), the shared epitope (SE) and the PTPN22-T allele (PTPN22) on the level of EBNA1 antibodies. We also determined the heritability of EBNA1 antibody levels. Results: IgA-EBNA1 antibody levels were increased in twins from RA discordant twin pairs irrespective of RA, ACPA or IgM-RF status. The IgG-EBNA1 antibody level was elevated in healthy co-twins from RA discordant twin pairs but not in RA affected twins. The IgM-EBNA1 antibody level was elevated in both RA twins and their healthy co-twins. The effect of RA on the IgA-EBNA1 antibody level was reversed when SE was present and with no effect of PTPN22. The heritability of IgA-, IgG- and IgM-EBNA1 antibody level was 40.6, 65.5, and 54.3%, with no effect of environment shared by the twins. Conclusion: EBNA1 antibody levels are distinctively different between patients with RA and healthy subjects but also between relatives of RA strongly predisposed to RA and healthy subjects. The high level of IgA EBNA1 antibodies associated with RA and a family predisposition to RA is attributable to both genetics incl. the shared epitope and environmental variation.

Similar lipid level changes in early rheumatoid arthritis patients following 1-year treat-to-target strategy with adalimumab plus methotrexate versus placebo plus methotrexate: secondary analyses from the randomised controlled OPERA trial.

To compare changes in low-density lipoprotein cholesterol and other lipids in patients with rheumatoid arthritis (RA) randomised to a 1-year treat-to-target strategy with either adalimumab plus methotrexate or placebo plus methotrexate. Prespecified secondary analyses from the OPERA trial, where 180 early and treatment-naïve RA patients received methotrexate 20 mg once weekly in combination with either placebo or subcutaneous adalimumab 40 mg every other week. Serum lipid levels were measured at baseline and after 1 year. Changes in lipid levels were analysed using mixed linear models based on the intention-to-treat (ITT) population. Overall, 174 patients were included in the ITT population (adalimumab plus methotrexate n = 86; placebo plus methotrexate n = 88). Differences between changes in lipid levels were low-density lipoprotein cholesterol 0.18 mmol/l [95% CI - 0.05 to 0.42], total cholesterol 0.27 mmol/l [- 0.002 to 0.54], high-density lipoprotein cholesterol 0.05 mmol/l [- 0.06 to 0.15], triglycerides 0.11 mmol/l [- 0.08 to 0.29], very-low-density lipoprotein cholesterol 0.03 mmol/l [- 0.05 to 0.12], and non-high-density lipoprotein cholesterol 0.22 mmol/l [- 0.02 to 0.46]. In early RA patients treated to tight control of inflammation over a period of 1 year with either adalimumab plus methotrexate or placebo plus methotrexate, changes in lipid levels were similar. Trial registration number: NCT00660647.

Programmed death ligand 2 - A link between inflammation and bone loss in rheumatoid arthritis.

OBJECTIVE: Active rheumatoid arthritis (RA) is accompanied by increased appendicular and axial bone loss, closely associated to the degree of inflammation. The programmed death-1 (PD-1) pathway is important for maintaining peripheral tolerance, and its ligand PD-L2 has recently been associated with bone morphogenetic protein activity. Here, we report that PD-L2 plays a central role in RA osteoimmunology. METHODS: Femoral bone mineral density (BMD) and trabecular bone microstructure were evaluated by micro-CT in wild type (WT) and PD-L2-/- mice. Osteoclasts were generated from RA synovial fluid mononuclear cells and peripheral blood monocytes. The effects of recombinant PD-L2, was evaluated by tartrate-resistant acid phosphatase (TRAP) activity and the development of bone erosions in the presence of anti-citrullinated protein antibodies (ACPA). Plasma soluble (s)PD-L2 levels were measured in patients with early (e)RA (n â€‹= â€‹103) treated with methotrexate alone or in combination with the TNF inhibitor Adalimumab. RESULTS: PD-L2-/- mice had a decreased BMD and deteriorated trabecular bone microstructure that was not related to the RANKL/OPG pathway. PD-L2 decreased TRAP activity in osteoclasts and decreased ACPA-induced erosions. In the RA synovial membrane PD-L2 was highly expressed especially in the lining layer and plasma sPD-L2 levels were increased in eRA patients and decreased with treatment. One-year sPD-L2 correlated inversely with erosive progression two years after treatment initiation with methotrexate and placebo. CONCLUSION: PD-L2 regulates bone homeostasis in RA. Our findings provide new insight into the relationship between the immune system and bone homeostasis, and suggest a potential therapeutic target for limiting inflammatory bone loss in RA.

Increased serum levels of microfibrillar-associated protein 4 (MFAP4) are not associated with clinical synovitis in rheumatoid arthritis but may reflect underlying cardiovascular comorbidity.

OBJECTIVES: To study circulating MFAP4 in rheumatoid arthritis (RA) and its associations with clinical phenotype. METHODS: Early RA (ERA): 47 patients with newly diagnosed, treatment naïve RA were included. Serum MFAP4, clinical and laboratory disease variables were recorded serially during 12 months of intensive synovitis suppressive treatment. Long-standing RA (LRA): 317 patients participated, all receiving DMARD treatment. Disease activity, autoantibody status, extra-articular manifestations and cardiovascular morbidity were recorded. Paired serum and synovial fluid samples were obtained from 13 untreated ERA patients. Healthy blood donors served as reference points. MFAP4 was quantified by AlphaLISA immunoassay. Univariate, multivariate and mixed effects regression models were applied in the statistical analysis. RESULTS: ERA: MFAP4 increased from baseline and was significantly elevated at the 12-month follow-up, 17.8 U/l [12.6;24.1] vs. healthy controls, 12.7 U/l [9.5;15.6], p<0.001. MFAP4 did not correlate with joint counts or C-reactive protein. LRA: MFAP4 was increased, 25.9 U/l [20.4;33.7] vs. healthy controls, 17.6 U/l [13.7;21.2], p<0.0001, but did not correlate with disease activity measures or presence of extra-articular manifestations. Notably, MFAP4 correlated inversely with smoking (p<0.0001) and presence of antibodies against cyclic citrullinated peptides (anti-CCP), p=0.005. There was a positive association with systolic blood pressure, p=0.001 and co-occurrence of three cardiovascular events and/or risk factors, p<0.0001. The serum:synovial fluid MFAP4 ratio was 2:1. CONCLUSIONS: MFAP4 increases from diagnostic baseline despite intensive treatment but does not associate with synovitis at early or late stages of RA. Correlation patterns indicate that increased MFAP4 may reflect enhanced RA-related vascular remodelling.

Site-specific absence of microfibrillar-associated protein 4 (MFAP4) from the internal elastic membrane of arterioles in the rheumatoid arthritis synovial membrane: an immunohistochemical study in patients with advanced rheumatoid arthritis versus osteoarthritis.

Microfibrillar-associated protein 4 (MFAP4) is a non-structural matrix protein with cell regulatory activities and a potential as seromarker for fibrosis. We aimed to study the occurrence of MFAP4 in the synovial membrane from patients with rheumatoid arthritis (RA) vs osteoarthritis (OA). Formaldehyde-fixed synovial tissue sections, from patients with RA (N = 6) and OA (N = 6) undergoing total hip arthroplasty, were deparaffinized and immunostained with monoclonal antibodies against MFAP4. Elastin was detected using ElastiKit. MFAP4 in serum (sMFAP4) and synovial fluid was measured by an immunoassay. MFAP4 was present in synovial biopsies from both RA and OA patients, particularly prominent in deep arterioles where it colocalized with elastin. Notably however, MFAP4 was absent from the internal elastic lamina in RA arterioles irrespective of disease duration and synovitis activity, while present although with irregular staining patterns in OA specimens. sMFAP4 was increased in RA and OA serum vs healthy controls: median (interquartile range) 29.8 (25.3-39.1) and 25.5 U/L (18.1-43.3) vs 17.7 U/L (13.7-21.2), p = 0.006 and p = 0.02, respectively The concentration of synovial fluid was lower than in serum in both RA and OA. These findings may suggest that MFAP4 is involved in adaptive vessel wall remodeling associated with chronic joint disease.

Validity and Responsiveness of Combined Inflammation and Combined Joint Damage Scores Based on the OMERACT Rheumatoid Arthritis MRI Scoring System (RAMRIS).

OBJECTIVE: The RAMRIS [Outcome Measures in Rheumatology rheumatoid arthritis (RA) magnetic resonance imaging (MRI) Scoring system] is used in clinical RA trials. We have investigated methods to combine the RAMRIS features into valid and responsive scores for inflammation and joint damage. METHODS: We used data from 3 large randomized early RA trials to assess 5 methods to develop a combined score for inflammation based on RAMRIS bone marrow edema, synovitis, and tenosynovitis scores, and a combined joint damage score based on erosions and joint space narrowing. Methods included unweighted summation, normalized summation, and 3 different variants of weighted summation of the RAMRIS features. We used a derivation cohort to calculate summation weights to maximize the responsiveness of the combined score. Construct validity of the combined scores was examined by assessing correlations to imaging, clinical, and biochemical measures. Responsiveness was tested by calculating the standardized response mean (SRM) and the relative efficiency of each score in a validation cohort. RESULTS: Patient characteristics, as well as baseline and followup RAMRIS scores, were comparable between cohorts. All combined scores were significantly correlated to other imaging, clinical, and biochemical measures. Inflammation scores combined by normalized and weighted summation had significantly higher responsiveness in comparison to unweighted summation, with SRM (95% CI) for unweighted summation 0.62 (0.51-0.73), normalized summation 0.73 (0.63-0.83), and weighted summation 0.74 (0.64-0.84). For the damage score, there was a trend toward higher responsiveness for weighted summation. CONCLUSION: Combined MRI scores calculated by normalized or weighted summation of individual MRI pathologies were valid and responsive.

Immune thrombocytopenia is associated with persistently deranged fibrosis-related seromarker profiles but low bone marrow fibrosis grades: A 2-year observational study on thrombopoietin receptor agonist treatment.

Bone marrow (BM) fibrosis is a potential side effect of thrombopoietin receptor agonist (TPO-RA) treatment. We aimed to investigate stromal seromarker profiles and growth factors in order to elucidate pathogenic and dynamic aspects of immune thrombocytopenia (ITP)-related BM fibrosis before and during TPO-RA treatment. Connective tissue metabolites [procollagen I and III peptides (PINP/PIIINP); hyaluronan (HYA), C-terminal-telopeptide (ICTP), and fibrosis-related growth factors (transforming growth factor-beta (TGF-beta), HGF, basic fibroblast growth factor)] were measured in blood samples acquired before initiation of TPO-RA and subsequently at 6-month intervals for up to 2 years. BM fibrosis was graded MF-0 in 8 (18%), MF-1 30 (65%), and MF-2 8 (18%) in the last available BM biopsy. In the 21 patients having more than one biopsy, the grade of fibrosis from the first to the last available biopsy decreased in 2 (10%), remained unchanged in 15 (71%), and increased in 4 (19%). Pretreatment levels of PIIINP, PINP, ICTP, and HYA were significantly increased in ITP versus controls. PINP, PIIINP, and HYA decreased on TPO-RA; ICTP remained unchanged. PINP:ICTP was lower before and during treatment compared to controls. Pretreatment, TGF-beta was lower than in controls; HGF exhibited the opposite pattern. HYA, ICTP, and TGF-beta tended to increase while PINP and platelet-derived growth factor tended to decrease with increasing fibrosis grade. In conclusion, ITP is associated with deranged patterns of extracellular matrix seromarkers and growth factors, indicating that BM stromal remodeling is enhanced. During TPO-RA treatment for up to 2 years, this profile was partially reversed while mild BM reticulin fibrosis was still present in the majority of patients. These observations likely reflect a BM injury by autoimmunity that is modified by TPO-RA.

The D-vitamin metabolite 1,25(OH)2 D in serum is associated with disease activity and Anti-Citrullinated Protein Antibodies in active and treatment naïve, early Rheumatoid Arthritis Patients.

RATIONALE: Sufficient levels of vitamin D seem to be essential for proper immune function, and low levels might be associated to disease activity in Rheumatoid Arthritis (RA). Most studies investigate only 25OHD and not the physiologically active vitamin D metabolite, 1,25(OH)2 D. OBJECTIVE: To investigate associations between serum level of vitamin D metabolites and disease activity parameters in 160 inflammatory active and treatment naïve early RA patients. Serum level of vitamin D metabolites (25OHD2 , 25OHD3 and 1,25(OH)2 D) was measured by isotope dilution mass spectrometry and radio-immunoassays at baseline. Disease characteristics were gender, number of tender joints, number of swollen joints, DAS28-CRP, HAQ, VAS-scores, CRP, erosive status (Total Sharp Score; TSS), ACPA and IgM-RF-status. Associations were evaluated using Spearman's and Wilcoxon rank-sum tests. The study was registered in clinical trials; trial registration number: NCT00209859. FINDINGS: Statistically significant inverse associations were found between the active metabolite 1,25(OH)2 D and DAS28-CRP (P = 0.004, rho = -0.23), HAQ (P = 0.005, rho = -0.22), CRP (P = 0.001, rho = -0.25), VASpatient-pain (P = 0.008, rho = -0.21), and a positive association was found to ACPA-status (P = 0.04). CONCLUSION: The vitamin D metabolite 1,25(OH)2 D was inversely associated with disease activity and positively associated with ACPA in treatment naïve and inflammatory active early RA. The results indicate that in RA, both the degree of inflammatory activity, and the diagnostic sensitivity and specificity might affect-or might be affected by the level of vitamin 1,25(OH)2 D.

Surfactant protein-D, a potential mediator of inflammation in axial spondyloarthritis.

Objectives: Surfactant protein-D (SP-D), an innate immune defence molecule of the collectin family, is expressed in lungs and additional extrapulmonary epithelia. SP-D has immune modulatory and anti-microbial effects depending on its oligomerization. The ratio of high molecular weight (HMW): low molecular weight (LMW) SP-D in serum is mainly determined by the Met11Thr polymorphism (SNP rs721917). We aimed to study the SP-D serum level and the molecular size distribution in patients with untreated axial spondyloarthritis (axSpA) as compared with control subjects. Methods: Thirty-four patients with disease modifier untreated axSpA according to the ASAS criteria, age 19-63 years, disease duration 3.9 (2.2-5.6) years were included. Demographics, smoking habits, HLA-B27 status, ASDAS, BASDAI, BASFI, BASMI and visual analogue scale scores were recorded. SP-D in serum was measured by ELISA. DNA was isolated from whole blood and single nucleotide polymorphism rs721917 was genotyped. SP-D molecular size distribution was determined using gel filtration chromatography. Results: SP-D in serum did not differ between patients with axSpA and healthy controls, 1177 (869, 1536) vs 910 (494, 1682) (P = 0.35) and SP-D did not correlate with disease activity. However, the HMW/LMW ratio of SP-D in serum was significantly lower in axSpA, 0.38 (0.18, 0.53) compared with controls 1.49 (0.37, 3.24) when adjusting for the Met11Thr polymorphism, gender, age, BMI and smoking (P = 0.0004). There was no correlation between HMW/LMW ratio and CRP or composite diseases outcome measures. Conclusion: We suggest that predominance of LMW oligomeric variants of SP-D may enhance local or systemic inflammatory responses in axSpA.

Type IV collagen metabolism is associated with disease activity, radiographic progression and response to tocilizumab in rheumatoid arthritis.

OBJECTIVES: The expanding spectrum of targeted therapies for rheumatoid arthritis (RA) implies a need for development of precision tools for disease assessment reflecting pathobiologic processes. Type IV collagen is an abundant protein of basement membranes, but is also present in the intercellular matrix of the synovial lining layer. We aimed to investigate the association of type IV collagen turnover with RA disease activity, response to IL-6 inhibition and radiographic progression. METHODS: C4M, a serologic marker of type IV collagen metabolism, was measured at baseline and at follow-up in serum samples of RA patients participating in the phase III studies LITHE (n=687) and RADIATE (n=217). Both were double-blinded, placebo-controlled clinical trials testing the safety and efficacy of 4 and 8 mg/kg tocilizumab (TCZ) in combination with methotrexate (MTX) vs. MTX plus placebo. Associations with disease activity, radiographic severity and ACR response were investigated. RESULTS: Baseline C4M correlated significantly with clinical disease parameters in both study populations, including DAS28, HAQ score and VASpain (all p<0.00001). C4M at baseline correlated significantly with change in JSN (p=0.001) and Sharp score (p=0.00002) at 52 weeks. TCZ lowered C4M by 11-40% in a dose dependent manner. The likelihood of achieving an ACR20 response by week 16 was associated with C4M suppression exceeding the median decrease at week 4 (p<0.0001). CONCLUSIONS: Type IV collagen remodelling was associated with disease activity and radiographic progression in RA and was persistently and dose-dependently suppressed by TCZ. These findings indicate that C4M may serve as a plausible biologic marker of destructive synovitis growth in RA.