In vitro osteoclastogenesis in autoimmune diseases - Strengths and pitfalls of a tool for studying pathological bone resorption and other disease characteristics

Osteoclasts play a critical role in bone pathology frequently associated with autoimmune diseases. Studying the etiopathogenesis of these diseases and their clinical manifestations can involve in vitro osteoclastogenesis, an experimental technique that utilizes osteoclast precursors that are relatively easily accessible from peripheral blood or synovial fluid. However, the increasing number of methodical options to study osteoclastogenesis in vitro poses challenges in translating findings to clinical research and practice. This review compares and critically evaluates previous research work based on in vitro differentiation of human osteoclast precursors originating from patients, which aimed to explain autoimmune pathology in rheumatic and enteropathic diseases. The discussion focuses primarily on methodical differences between the studies, including the origin of osteoclast precursors, culture conditions, and methods for identifying osteoclasts and assessing their activity. Additionally, the review examines the clinical significance of the three most commonly used in vitro approaches: induced osteoclastogenesis, spontaneous osteoclastogenesis, and cell co-culture. By analyzing and integrating the gathered information, this review proposes general connections between different studies, even in cases where their results are seemingly contradictory. The derived conclusions and future directions aim to enhance our understanding of a potential and limitations of in vitro osteoclastogenesis and provide a foundation for discussing novel methods (such as osteoclastogenesis dynamic) and standardized approaches (such as spontaneous osteoclastogenesis) for future use in autoimmune disease research.

ASAS-EULAR recommendations for the management of axial spondyloarthritis: 2022 update

OBJECTIVES

To update the Assessment of SpondyloArthritis international Society (ASAS)-EULAR recommendations for the management of axial spondyloarthritis (axSpA).

METHODS

Following the EULAR Standardised Operating Procedures, two systematic literature reviews were conducted on non-pharmacological and pharmacological treatment of axSpA. In a task force meeting, the evidence was presented, discussed, and overarching principles and recommendations were updated, followed by voting.

RESULTS

Five overarching principles and 15 recommendations with a focus on personalised medicine were agreed: eight remained unchanged from the previous recommendations; three with minor edits on nomenclature; two with relevant updates (#9, 12); two newly formulated (#10, 11). The first five recommendations focus on treatment target and monitoring, non-pharmacological management and non-steroidal anti-inflammatory drugs (NSAIDs) as first-choice pharmacological treatment. Recommendations 6-8 deal with analgesics and discourage long-term glucocorticoids and conventional synthetic disease-modifying antirheumatic drugs (DMARDs) for pure axial involvement. Recommendation 9 describes the indication of biological DMARDs (bDMARDs, that is, tumour necrosis factor inhibitors (TNFi), interleukin-17 inhibitors (IL-17i)) and targeted synthetic DMARDs (tsDMARDs, ie, Janus kinase inhibitors) for patients who have Ankylosing Spondylitis Disease Activity Score ≥2.1 and failed ≥2 NSAIDs and also have either elevated C reactive protein, MRI inflammation of sacroiliac joints or radiographic sacroiliitis. Current practice is to start a TNFi or IL-17i. Recommendation 10 addresses extramusculoskeletal manifestations with TNF monoclonal antibodies preferred for recurrent uveitis or inflammatory bowel disease, and IL-17i for significant psoriasis. Treatment failure should prompt re-evaluation of the diagnosis and consideration of the presence of comorbidities (#11). If active axSpA is confirmed, switching to another b/tsDMARD is recommended (#12). Tapering, rather than immediate discontinuation of a bDMARD, can be considered in patients in sustained remission (#13). The last recommendations (#14, 15) deal with surgery and spinal fractures.

CONCLUSIONS

The 2022 ASAS-EULAR recommendations provide up-to-date guidance on the management of patients with axSpA.

ASAS-EULAR recommendations for the management of axial spondyloarthritis: 2022 update

OBJECTIVES

To update the Assessment of SpondyloArthritis international Society (ASAS)-EULAR recommendations for the management of axial spondyloarthritis (axSpA).

METHODS

Following the EULAR Standardised Operating Procedures, two systematic literature reviews were conducted on non-pharmacological and pharmacological treatment of axSpA. In a task force meeting, the evidence was presented, discussed, and overarching principles and recommendations were updated, followed by voting.

RESULTS

Five overarching principles and 15 recommendations with a focus on personalised medicine were agreed: eight remained unchanged from the previous recommendations; three with minor edits on nomenclature; two with relevant updates (#9, 12); two newly formulated (#10, 11). The first five recommendations focus on treatment target and monitoring, non-pharmacological management and non-steroidal anti-inflammatory drugs (NSAIDs) as first-choice pharmacological treatment. Recommendations 6-8 deal with analgesics and discourage long-term glucocorticoids and conventional synthetic disease-modifying antirheumatic drugs (DMARDs) for pure axial involvement. Recommendation 9 describes the indication of biological DMARDs (bDMARDs, that is, tumour necrosis factor inhibitors (TNFi), interleukin-17 inhibitors (IL-17i)) and targeted synthetic DMARDs (tsDMARDs, ie, Janus kinase inhibitors) for patients who have Ankylosing Spondylitis Disease Activity Score ≥2.1 and failed ≥2 NSAIDs and also have either elevated C reactive protein, MRI inflammation of sacroiliac joints or radiographic sacroiliitis. Current practice is to start a TNFi or IL-17i. Recommendation 10 addresses extramusculoskeletal manifestations with TNF monoclonal antibodies preferred for recurrent uveitis or inflammatory bowel disease, and IL-17i for significant psoriasis. Treatment failure should prompt re-evaluation of the diagnosis and consideration of the presence of comorbidities (#11). If active axSpA is confirmed, switching to another b/tsDMARD is recommended (#12). Tapering, rather than immediate discontinuation of a bDMARD, can be considered in patients in sustained remission (#13). The last recommendations (#14, 15) deal with surgery and spinal fractures.

CONCLUSIONS

The 2022 ASAS-EULAR recommendations provide up-to-date guidance on the management of patients with axSpA.

AB0108 INFLAMMATION IN axSpA AS A DISRUPTOR OF BONE METABOLISM – THE EFFECT OF PATIENTS’ SERA ON AN IN VITRO BONE MODEL

Background

In axial spondyloarthritis (axSpA), two opposing processes of bone resorption and neogenesis are closely related, with a common denominator – chronic inflammation. This pathological condition affects osteoblasts, among other cells, residing in sites of inflamed tissue, but it can also activate mononuclear precursors in the blood to form osteoclasts [1,2]. To this day, it is not yet clear how the interplay between osteoblasts and osteoclasts affects pathogenesis of axSpA.

Objectives

The aim was to evaluate the effect of sera from patients with different forms of the disease, non-radiographic (nr-axSpA) and radiographic (r-axSpA) including ankylosing spondylitis, in comparison to the effect of sera from healthy individuals (axC) on osteoblasts and osteoclasts co-culture.

Methods

The inflammation characteristic for each diagnose was simulated by age- and sex-matched pools of 12 nr-axSpA and 12 r-axSpA patients‘ sera, healthy condition by a pool of 12 axC sera. We used THP-1 monocytic cell line and SaOS-2 osteosarcoma cell line co-culture to model bone physiology. After THP-1 adhesion, SaOS-2 cells were added with 10 % of nr-axSpA, r-axSpA or axC sera, respectively, in the media for 14 days. Activity of osteoblastic alkaline phosphatase (ALP) and osteoclastic enzymes tartrate-resistant acid phosphatase (TRAP), cathepsin K (CTSK) and carbonic anhydrase II (CAII) on days (D) 1, 7 and 14 were measured. Simultaneously, we examined metabolic activity (MTS assay), cell proliferation (PicoGreen assay) and mRNA expression of selected genes in co-culture.

Results

In all three studied co-cultures the ALP activity increased with length of the cultivation; nevertheless, the onset of the activity in D1 was more rapid in axC sera compared to nr-axSpA (P<0.05) and r-axSpA (P<0.001). The ALP activity increase from D1 to D14 was 4.9 fold in axC, 5.7 fold in nr-axSpA and 6 fold in r-axSpA. Moreover, rise of ALP gene expression corresponds well with rise of ALP activity. TRAP activity peaked in all sera on D7 and decreased again towards D14, mirroring the same mRNA expression profile. The TRAP activity on D7 was highest in axC sera and lowest in r-axSpA (P<0.01). Gradual drop of CA II activity from D1 to D14 was detected in co-cultures with axC and nr-axSpA sera; in r-axSpA, however, the activity increased 1.42 times from D7 to D14 and was thus significantly higher on D 14 compared to cultures in other two sera (P<0.0001). In all cultures, CTSK activity increased from D7 to D14. Activity was highest in culture with axC sera (nr-axSpA D7 and D14 P<0.0001; r-axSpA D7 P<0.0001, D14 P<0.05). A gradual increase in cell proliferation was observed in axC sera and was thus significantly higher compared to both patients’ sera on D14 (P<0.0001). In contrast, the proliferation in patients‘ sera peaked on D7 with the significantly highest D7 proliferation observed in r-axSpA (P<0.05). While the metabolic activity per cell followed U shape trend in all co-cultures, the changes were more distinct in patients‘ sera: 2 fold drop in r-axSpA, 1.6 fold in nr-AxSpA and 1.3 fold in axC sera on D7 followed by increase of 3.4 fold in r-AxSpA, 2.9 fold in nr-AxSpA and 1.8 fold in axC on D14.

Conclusion

Data acquired from the in vitro bone model point to an imbalance in the enzymatic activity of osteoclasts and to changes in the metabolic activity and proliferation of both, osteoblasts and osteoclasts. These changes seem to be caused by inflammatory agents in patients’ sera. However, the changes are not the same in both forms of disease, which may explain differences between nr- and r-axSpA symptoms.

References

[1]Sieper, J., Braun, J., Dougados, M., & Baeten, D. (2015). Axial spondyloarthritis. Nature reviews. Disease primers, 1, 15013. https://doi.org/10.1038/nrdp.2015.13

[2]Van Mechelen, M., Gulino, G. R., de Vlam, K., & Lories, R. (2018). Bone Disease in Axial Spondyloarthritis. Calcified tissue international, 102(5), 547–558. https://doi.org/10.1007/s00223-017-0356-2

Acknowledgements

Grant support: Progres Q43 and SVV260436

Disclosure of Interests

None declared

OP0105 miRNOME PROFILE IN PATIENTS WITH AXIAL SPONDYLOARTHRITIS

Background

microRNAs (miRNAs) are small non-coding RNAs regulating up to 60 % of human mRNAs, including genes related to axial spondyloarthritis (axSpA) (1).

Objectives

This study aims to profile miRNome and to identify candidate miRNAs determining disease severity in patietns with non-radiographic (nr) and radiographic (r) axSpA.

Methods

The miRNome profiling experiment included peripheral blood mononuclear cells (PBMCs) of 96 subjects (38 patients with nr-axSpA, 38 patients with r-axSpA and 20 healthy controls). Firstly, massive parallel sequencing on NextSeq 500 (MPS, Illumina) was performed for miRNA screening. Selected candidate miRNAs were further validated using the qRT-PCR system (SmartChip) on the validation cohort of 141 subjects (47 patients with nr-axSpA, 44 patients with r-axSpA and 50 healthy controls). We employed the DESeq2 algorithm and generalized linear modelling with a negative binomial assumption (GLM-NB) to evaluate the association of candidate miRNAs to axSpA subtype and clinical disease activity (ASDAS and CRP).

Results

MPS revealed 432 unique miRNAs in all samples. We identified 13 differently expressed miRNAs in axSpA patients compared to healthy controls, and 14 differently expressed miRNAs in axSpA patients with high to very high ASDAS compared to patients with inactive disease. Data from validation cohort revealed that the expression level of miR-4286 was higher in patients with very high disease activity compared to patients with inactive disease. Simultaneously, miR-4286 positively correlated with ASDAS. miR-4286 has been recently associated with osteogenesis and angiogenesis (2). None of the validated miRNAs was associated with the levels of CRP.

Conclusion

In this study, we identified that miR-4286 is related to disease activity and could play a role in the pathogenesis of axSpA.

References

[1]Prajzlerová K, Grobelná K, Hušáková M, et al. Association between circulating miRNAs and spinal involvement in patients with axial spondyloarthritis. PLoS One. 2017 Sep 22;12(9):e0185323.

[2]Yu H, Wang K, Liu P, et al. miR-4286 functions in osteogenesis and angiogenesis via targeting histone deacetylase 3 and alleviates alcohol-induced bone loss in mice. Cell Prolif. 2021 Jun;54(6):e13054.

Acknowledgements

Supported by MHCR No. 023728, BBMRI-CZ LM2018125 and SVV 260 523.

Disclosure of Interests

None declared

Effect of a Monascus sp. Red Yeast Rice Extract on Germination of Bacterial Spores

The pink-red color of traditional sausages (cured meat) is the result of nitrite addition and the formation of nitrosomyoglobin. However, the pleasant color of processed meat products is a side effect of nitrite addition while the main anticipated goal is to suppress the germination of clostridial spores. The fungus Monascus is known as a producer of oligoketide pigments, which are used in Asian countries, especially in China, for coloring foods, including meat products. Although, different biological activities of Monascus pigments have been tested and confirmed in many studies, their effect on germination of bacterial spores has never been investigated. This study is focused on testing the activity of red yeast rice (RYR) extract, containing monascin, rubropunctatin, rubropunctamine complexes and monascuspiloin as the main pigments, on germination of Clostridium and Bacillus spores. It was found that addition of nitrite alone, at the permitted concentration, had no effect on spore germination. However, the combined effects of nitrite with NaCl, tested after addition of pickling salt, was efficient in inhibiting the germination of C. beijerinckii spores but had no effect on B. subtilis spores. In contrast, total suppression of C. beijerinckii spore germination was reached after addition of RYR extract to the medium at a concentration of 2% v/v. For B. subtilis, total inhibition of spore germination was observed only after addition of 4% v/v RYR extract to the medium containing 1.3% w/w NaCl.

Plasma heat shock protein 90 levels in patients with spondyloarthritis and their relation to structural changes: a cross-sectional study

Aim: Heat shock protein 90 (Hsp90) is a molecular chaperone regulating immune response. We aimed to assess systemic Hsp90 as a biomarker for spondyloarthritis (SpA). Materials & methods: Total of 80 axial SpA (axSpA) and 22 psoriatic arthritis patients and a corresponding number of age- and sex-matched healthy controls (HC) were included. Plasma Hsp90 levels were measured by ELISA. Results: Hsp90 was significantly increased in axSpA patients compared with HC (median interquartile range: 15.7 [10.5-19.8] vs 8.3 [6.6-11.8] ng/ml, p < 0.001). Moreover, Hsp90 was superior to C-reactive protein in differentiating axSpA (and both radiographic axSpA [r-axSpA] and nonradiographic-axSpA) from HC. Hsp90 levels correlated with bone marrow edema of sacroiliac joints in r-axSpA patients (r = 0.594, p = 0.019). Conclusion: Hsp90 could become a biomarker for active inflammation in r-axSpA, and can better distinguish axSpA patients from healthy subjects than C-reactive protein.

Efficiency of DNA Isolation Methods Based on Silica Columns and Magnetic Separation Tested for the Detection of Mycobacterium avium Subsp. Paratuberculosis in Milk and Faeces

Timely and reliable detection of animals shedding Mycobacterium avium subsp. paratuberculosis (MAP) should help to effectively identify infected animals and limit infection transmission at early stages to ensure effective control of paratuberculosis. The aim of the study was to compare DNA extraction methods and evaluate isolation efficiency using milk and faecal samples artificially contaminated by MAP with a focus on modern instrumental automatic DNA isolation procedures based on magnetic separation. In parallel, an automatic and manual version of magnetic separation and two methods of faecal samples preparation were compared. Commercially available DNA isolation kits were evaluated, and the selected kits were used in a trial of automatic magnetic beads-based isolation and compared with the manual version of each kit. Detection of the single copy element F57 was performed by qPCR to quantify MAP and determine the isolation efficiency. The evaluated kits showed significant differences in DNA isolation efficiencies. The best results were observed with the silica column Blood and Tissue kit for milk and Zymo Research for faeces. The highest isolation efficiency for magnetic separation was achieved with MagMAX for both matrices. The magnetic separation and silica column isolation methods used in this study represent frequently used methods in mycobacterial diagnostics.

SAT0589 RISK FOR PSYCHIATRIC HOSPITALIZATION FOLLOWING A RHEUMA-RELATED HOSPITALIZATION: RESULTS FROM A CZECH NATIONWIDE, COHORT STUDY

Background:

Cohort studies using nationwide health registers have shown an increased risk for affective and anxiety disorders in people with ankylosing spondylitis (AS) and rheumatoid arthritis (RA) (1-3). Moreover, a nationwide cohort study demonstrated an increased risk for mental disorders in people with rheumatic diseases (4).

Objectives:

We aimed to investigate the risk for psychiatric hospitalization following a hospitalization for rheumatic disease.

Methods:

Using data from the Czech nationwide register of all-cause hospitalizations, we obtained 4 971 individuals hospitalized (index hospitalization) between 2004 and 2012 for rheumatic diseases - RA, spondyloarthritis (including AS, psoriatic arthritis and undifferentiated spondyloarthritis), systemic lupus erythematosus and systemic sclerodermia, with no history of psychiatric and rheuma-related hospitalization in the previous 10 years from the index hospitalization. On these individuals, we randomly matched (on age, gender and year of index hospitalization) controls that were hospitalized in the same time period for a non-rheumatic disease and have no history of psychiatric and rheumatic hospitalization in the last 10 years from their index hospitalization, in the ratio of 1:5. We employed conditional logistic regression for assessing the risk for psychiatric hospitalization in the subsequent 3 years from the index hospitalization. To strengthen our results, we repeated the matching step 100 times and run the analysis on each resulting dataset separately, and pooled the results. The findings are expressed as odds ratios (OR) with 95% confidence intervals (95% CI).

Results:

We identified an elevated risk for psychiatric (OR = 1.34, 95% CI = 1; 1.78) and for affective disorders (OR = 2.19, 95% CI = 1.17; 4.1) in people hospitalized for rheumatic diseases. We did not find a statistically significant association with organic, psychotic and anxiety disorders.

Conclusion:

There is an increased risk for experiencing a psychiatric disorder in the period of 3 years after a rheuma-related hospitalization.

References:

[1]Shen C-C, Hu L-Y, Yang AC, Kuo BI-T, Chiang Y-Y, Tsai S-J. Risk of Psychiatric Disorders following Ankylosing Spondylitis: A Nationwide Population-based Retrospective Cohort Study. The Journal of Rheumatology. 2016;43(3).

[2]Park J-S, Jang H-D, Hong J-Y, Park Y-S, Han K, Suh S-W, et al. Impact of ankylosing spondylitis on depression: a nationwide cohort study. Scientific Reports. 2019;9(1):6736.

[3]Hsu C-C, Chen S-C, Liu C-J, Lu T, Shen C-C, Hu Y-W, et al. Rheumatoid Arthritis and the Risk of Bipolar Disorder: A Nationwide Population-Based Study. PLOS ONE. 2014;9(9).

[4]Sundquist K, Li X, Hemminki K, Sundquist J. Subsequent Risk of Hospitalization for Neuropsychiatric Disorders in Patients With Rheumatic Diseases: A Nationwide Study From Sweden. Archives of General Psychiatry. 2008;65(5):501-7.

Acknowledgments:

Supported by the project (Ministry of Health Czech Republic) for conceptual development of research organization 00023728 (Institute of Rheumatology).

Disclosure of Interests:

Tomáš Formánek: None declared, Karolina Mladá: None declared, Marketa Husakova Speakers bureau: Novartis

AB0061 INVOLVEMENT OF CELL-FREE DNA IN THE DIFFERENTIATION OF OSTEOCLASTS – IMPLICATIONS FOR CLINICAL RESEARCH

Background:

Cell-free DNA (cfDNA) is a molecule with undisputable immunogenic potential[1]. Its role is well established in etiopathogenesis of systemic lupus erythematosus and many reports suggest it may play an important role in other rheumatic diseases[2]. Patients suffering from rheumatic diseases are at higher risk of osteoporosis[3], which may be a consequence of increased generation of osteoclasts (OC). Traditionally, increased formation of OC is attributed to changes in cytokine network[4]. It is not yet known whether cfDNA can also act on mononuclear precursors and influence their differentiation into OC.

Objectives:

The aim of this study was to assess role of cfDNA in differentiation of bone resorbing cells in rheumatic diseases. For this purpose, deoxyribonuclease I (DNAse) was employed to eliminate cfDNA from sera of patients and healthy controls (HC) used for cell culture.

Methods:

In order to evaluate effects of cfDNA on osteoclastogenesis, anin vitroexperiment of peripheral blood monocytes (PBM) cultures was designed. Axial spondyloarthritis (AxSpA) was chosen as a model of rheumatic disease. Sera of AxSpA patients (total n=13) and healthy controls (total n=13) were collected and subsequently used in cell cultures. PBM of 13 healthy donors were cultured in presence of 25 ng/ml macrophage colony-stimulating factor (M-CSF), 0,5 ng/ml receptor-activator of nuclear factor kappa B ligand (RANKL) and 10 % of pooled AxSpA or HC sera, respectively. Serum counterpart treated with DNAse was used in parallel. After 14 days, cells were stained for tartrate-resistant acid phosphatase (TRAP) and counted. TRAP positive cells with 3 or more nuclei were recognized as OC.

Results:

On average, differentiation of OC in presence of AxSpA sera led to higher osteoclastogenesis compared to DNAse-treated counterpart (137 vs. 61; p < 0.01). In a similar way, treatment of HC sera with DNAse greatly diminished osteoclastogenesis compared to untreated sera (17 vs. 111; p < 0.05). Overall, the effect of cfDNA depletion in HC sera regarding OC differentiation was more than 2,5× higher than the effect of cfDNA depletion in AxSpA sera (p < 0.001).

Conclusion:

Results of our pilot study indicate possible involvement of cfDNA in osteoclastogenesis. Decrease in number of OC after cfDNA depletion in both AxSpA sera and HC sera suggests that cfDNA effect in osteoclastogenesis is non-specific with respect to healthy condition and may represent universal link between innate immunity and bone metabolism. Lower effect of cfDNA depletion in AxSpA sera on osteoclastogenesis is very possibly owing to presence of other inflammatory molecules, which influence osteoclastogenesis. Future research might identify cfDNA as useful therapeutic target to decrease osteoporosis risk not only in patients with rheumatic and autoimmune diseases, where pathological bone resorption is imminent, but also in general aging population.

References:

[1]Pisetsky, D. S. (2012). The origin and properties of extracellular DNA: from PAMP to DAMP. Clinical Immunology, 144(1), 32-40.

[2]Lood, C. J., & Duvvuri, B. (2019). Cell-free DNA as a biomarker in autoimmune rheumatic diseases. Frontiers in immunology, 10, 502.

[3]Maruotti, N., Corrado, A., & Cantatore, F. P. (2014). Osteoporosis and rheumatic diseases. Reumatismo, 125-135.

[4]Amarasekara, D. S., Yu, J., & Rho, J. (2015). Bone loss triggered by the cytokine network in inflammatory autoimmune diseases. Journal of immunology research, 2015.

Acknowledgments:

Project MH CR 00023728 & MEYS CR Progres Q43

Disclosure of Interests:

Patrik Škubica: None declared, Jana Horinkova: None declared, Monika Gregová Consultant of: Novartis, Abbvie, Paid instructor for: Novartis, Speakers bureau: Novartis, Abbvie, MSD, Karel Pavelka Consultant of: Abbvie, MSD, BMS, Egis, Roche, UCB, Medac, Pfizer, Biogen, Speakers bureau: Abbvie, MSD, BMS, Egis, Roche, UCB, Medac, Pfizer, Biogen, Marketa Husakova Speakers bureau: Novartis, Pavlina Dankova: None declared

AB0120 THE EFFECT OF INFLAMMATORY SERA FROM DIFFERENT FORMS OF AXIAL SPONDYLOARTHRITIS ON THE OSTEOCLASTOGENIC POTENTIAL OF MONONUCLEAR PRECURSORS IN BLOOD

Background:

Spondyloarthritis (SpA) is characterized by pathological bone resorption and higher risk of osteoporosis. Inflammation accompanying the disease may activate mononuclear precursors in blood that are able to differentiate into osteoclasts, bone resorbing cells[1,2], and thus substantially contribute to bone resorption and aggravation of symptoms characteristic for this chronic disease.

Objectives:

The aim of this pilot study is i) to figure out whether the inflammatory factors present in blood sera of SpA patients activate the osteoclastogenic potential of peripheral blood monocytes (PBM) derived from healthy subjects; ii) to find out whether this effect differs among sera from three forms of SpA, short-term non-radiographic (nr-axSpA) and radiographic (r-axSpA) SpA, and long-term ankylosing spondyloarthritis (AS), and finally iii) to assess whether the stimulatory effect of serum from SpA patients on osteoclastogenesis of healthy PBM reflects the altered clinical markers of inflammation and bone metabolism.

Methods:

To simulate inflammatory condition characteristic for nr-axSpA, r-axSpA or AS, we created pool of 10 AS sera together with age- and sex-matched pools of nr-axSpA, r-axSpA and AxC (sera from healthy subjects). Disease duration of nr-axSpA and r-axSpA was set up to less than 2 years. The ASDAS score of AS form was significantly higher compared to the score of short-term forms of disease (P < 0.05). PBM from 6 healthy donors were cultured for 14 days in DMEM supplemented with 25 ng/ml macrophage colony-stimulating factor (M-CSF), 0.5 ng/ml receptor-activator of nuclear factor kappa B ligand (RANKL) and in parallel with 10% pooled human sera nr-axSpA, r-axSpA, AS and AxC. TRAP positive cells with 3 or more nuclei were recognized as osteoclasts and counted.

Results:

Cultivation of PBM in the presence of both, diseased and healthy human sera increases number of osteoclasts in comparison to cultures without human sera. The strongest osteoclastogenic capacity develop PBM affected by pooled AS sera (2.9 times increase in osteoclast number compared to culture without human sera, P < 0.05), the lowest osteoclastogenic potential was detected in culture with pooled sera from healthy donors (2.1 times, P = NS). Pooled nr-axSpA, r-axSpA and AS sera do not appear to differ significantly among each other in size of their effect on PBM; nevertheless, trend to lowest numbers of osteoclasts can be seen in culture with r-axSpA sera (P = NS).

Conclusion:

Cytokine milieu in human sera seems to have a pro-osteoclatogenic effect regardless of its origin with respect to healthy condition. However, inflammatory factors present in the sera of SpA patients enhance the osteoclastogenic potential of PBM, as documented especially in AS sera presenting with significant, 7fold increased serum CRP levels (P = 0.003), and thus may contribute to aggravation of the osteoporotic condition of SpA patients.

References:

[1]Amarasekara, DS, Yu, J, Rho, J (2015). Bone loss triggered by the cytokine network in inflammatory autoimmune diseases.J Immune Res.2015:832127

[2]Amarasekara, D S, Yun H, Kim S, Lee N, Kim H, Rho J (2018). Regulation of Osteoclast Differentiation by Cytokine Networks.Immune Netw.Feb 7;18(1):e8

Acknowledgments:

Project MH CR 00023728 and MEYS CR Progres Q43

Disclosure of Interests:

Pavlina Dankova: None declared, Eva Sebova: None declared, Patrik Škubica: None declared, Jana Horinkova: None declared, Monika Gregová Consultant of: Novartis, Abbvie, Paid instructor for: Novartis, Speakers bureau: Novartis, Abbvie, MSD, Karel Pavelka Consultant of: Abbvie, MSD, BMS, Egis, Roche, UCB, Medac, Pfizer, Biogen, Speakers bureau: Abbvie, MSD, BMS, Egis, Roche, UCB, Medac, Pfizer, Biogen, Marketa Husakova Speakers bureau: Novartis

Clinical improvement and reduction in serum calprotectin levels after an intensive exercise programme for patients with ankylosing spondylitis and non-radiographic axial spondyloarthritis

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.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-1180-1) contains supplementary material, which is available to authorized users.

Microarray analysis of circulating micro RNAs in the serum of patients with polymyositis and dermatomyositis reveals a distinct disease expression profile and is associated with disease activity

OBJECTIVES

The aim of this study was a large scale investigation of myositis-associated circulating miRNA molecules and also determination of expression of these candidate molecules in relation to clinical activity of myositis.

METHODS

RNA, containing also miRNAs, was isolated from sera of 28 patients suffering from idiopathic inflammatory myopathies (IIM) and 16 healthy controls. Expression of miRNAs was determined using a miRNA microarray method. Statistical analysis of miRNA expression was carried out using Arraystar software.

RESULTS

Our results showed 23 significantly differentially expressed miRNAs. Six miRNAs were differentially expressed in IIM compared to healthy controls. In dermatomyositis (DM) we found 3 and in polymyositis (PM) 6 differentially expressed miRNAs compared to controls. Three miRNAs were up-regulated in patients with highly active disease compared to patients with low disease activity. Furthermore, we found 26 significantly differentially expressed miRNAs in SLE patients compared to IIM, DM and PM patients.

CONCLUSIONS

This is the first study that comprehensively describes expression levels of circulating miRNAs in serum of patients suffering from IIM. It can be expected that some of these deregulated miRNA molecules are involved in aetiology of IIM and may potentially serve as molecular markers for IIM development or for monitoring of disease activity.

Elevated serum prolactin levels as a marker of inflammatory arthritis in psoriasis vulgaris

BACKGROUND AND AIMS

Psoriasis vulgaris (PV) is complicated in up to 40% patients by the inflammatory joint disease psoriatic arthritis (PsA). Neither the aetiology of the arthritis nor specific laboratory markers for its disease activity have been clearly elucidated. Prolactin (PRL) acts as a cytokine with immunomodulatory functions and plays a role in skin and joint biology. The results on PRL however as a marker are unclear. The aim of this study was to confirm whether serum PRL levels reflect systemic complications of PV, like inflammatory joint disease and/or can serve as a marker of disease activity in both cases.

METHODS

A total of 70 patients with PV without arthritis and 40 patients suffering from PsA were included. In all patients, we determined skin disease activity according to the PASI index and in PsA, active disease assessed as swollen or tender joints. The control group included 27 age and sex matched healthy individuals. The concentration of PRL in the serum was measured by immunoradiometric assays.

RESULTS

The PRL serum levels were significantly increased in PsA patients (299.2±28.29 mIU/L) compared to PV only patients (201.4.2±11.72 mIU/L), P = 0.0003 and healthy individuals (198.2±15.31 mIU/L), P = 0.007. The serum PRL levels in PsA with active disease 336.8±42.50 (mIU/L) were higher than in PV and controls, P < 0.0001 and P = 0.002 respectively. In PV only patients, there was no correlation between PASI and PRL levels.

CONCLUSION

Our results showed that PRL serum levels are a marker of active arthritis in PsA and reflects systemic complication rather than local skin activity.