Identification of patient endotypes and adalimumab treatment responders in axial spondyloarthritis using blood-derived extracellular matrix biomarkers

OBJECTIVE

To explore the potential of a panel of ECM remodelling markers as endotyping tools for axial spondyloarthritis (axSpA) by separating patients into subtypes and investigate how they differ among each other in disease activity scores and response to treatment with adalimumab.

METHODS

In three axSpA studies, a panel of 14 blood-based ECM biomarkers related to formation of collagen (PRO-C2, PRO-C3, PRO-C6), degradation of collagen by metalloproteinases (C1M, C2M, T2CM, C3M, C4M, C6M, C10C), matrix metalloproteinase (MMP)-degraded prolargin (PROM), MMP-degraded and citrullinated vimentin (VICM), basement membrane turnover (PRO-C4) and neutrophil activity (CPa9-HNE) were assessed to enable patient clustering (endotyping). MASH (n=41) was a cross-sectional study, while Adalimumab in Axial Spondyloarthritis study (ASIM,n=45) and Danish Multicenter Study of Adalimumab in Spondyloarthritis (DANISH, n=49) were randomised, double-blind placebo-controlled trials of adalimumab versus placebo every other week for 6 or 12 weeks, respectively, followed by active treatment. Biomarker data were log-transformed, standardised by mean centering and scaled by the SD prior to principal component analysis and K-means clustering.

RESULTS

Based on all three studies, we identified two orthogonal dimensions reflecting: (1) inflammation and neutrophil activity (driven by C1M and CPa9-HNE) and (2) collagen turnover (driven by PRO-C2). Three endotypes were identified: high inflammation endotype (Endotype1), low inflammation endotype (Endotype 2) and high collagen turnover endotype (Endotype3). Endotype1 showed higher disease activity (Ankylosing Spondylitis Disease Activity Score (ASDAS)) at baseline compared with Endotype2 and Endotype3 and higher percentage of patients responding to adalimumab based on ASDAS clinical improvement at week 24. Endotype3 showed higher percentage of patients with 50% improvement in Bath Ankylosing Spondylitis Disease Activity Index response at week 24 compared with Endotype2.

CONCLUSION

These endotypes differ in their tissue remodelling profile and may in the future have utility for patient stratification and treatment tailoring.

POS0955 EXTRACELLULAR MATRIX PROTEIN TURNOVER MARKERS ARE ASSOCIATED WITH axSpA – A COMPARISON WITH CONTROL SUBJECTS WITH OR WITHOUT PELVIC, BUTTOCK OR BACK PAIN

Background:

Axial spondyloarthritis (axSpA) is a common chronic inflammatory disease, associated with extracellular matrix (ECM) remodeling of the cartilage, bone and connective tissues. The primary symptom of axSpA is back pain, caused by inflammation. However, there is a medical need to truly identify patients with axSpA from other subjects with buttock or low back pain attributable to other reasons. Tissue-derived extracellular (ECM) markers quantified in serum may serve to differentiate axSpA patients from other diagnostic entities.

Objectives:

To investigate circulating ECM turnover markers as potential biomarkers to differentiate patients with axSpA from a control group of subjects with buttock or pelvic pain attributed to other reasons, including postpartum women and healthy subjects.

Methods:

Biomarkers of ECM degradation/chronic inflammation (C1M, C3M, C4M, C6M, CRPM, C10C and COL10NC) and ECM formation (PRO-C3 and PRO-C6) were measured in 204 participants from the MASH study [1] (Table 1). Biomarker levels were compared among patients with axSpA and control group, and two new variables (Type 3 and Type 6) were included, corresponding to the index of formation/degradation of type III and type VI collagen respectively. The biomarker data was log10 transformed for normalization when necessary and linear regression models with pairwise comparisons were performed. Clinical scores and the SPARCC MRI scores for sacroiliac joint (SIJ) inflammation were correlated with the biomarkers data (data not shown).

Table 1.

Comparison of blood-tested biomarkers levels in MASH study. Data was adjusted for confounders age, gender, and body mass index (BMI).

Biomarkers(Mean (SD))Patientswith axSpA(n = 41)Control groups (n=163)pC1M84.3 (85.8)36.2 (22.1)<0.0001C3M15.6 (4.0)13.9 (3.0)0.011C4M34.9 (10.2)27.9 (7.7)<0.0001C6M20.5 (5.8)17.4 (4.2)<0.0001CRPM11.9 (2.9)11.0 (5.9)0.027C10C2567 (462)2568 (560)0.31COL10NC9.15 (5.81)9.43 (8.27)0.43PRO_C310.2 (2.5)11.3 (3.0)0.0052PRO_C66.94 (2.45)6.86 (2.53)0.93Type 3 (PRO-C3/C3M)0.70 (0.28)0.86 (0.31)0.0004Type 6 (PRO-C6/C6M)0.36 (0.16)0.41 (0.14)0.0024

Results:

We found that patients with axSpA had significantly increased MMP-mediated degradation of type I (C1M), type III (C3M), type IV (C4M) and type VI (C6M) collagens (p<0.0001, p=0.01,p<0.001,p<0.001, respectively), and CRP-metabolite (CRPM, p=0.027), and significantly decreased formation of type III collagen (p= 0.052) compared with control groups when adjusting for age, gender and body mass index (BMI). Significantly decreased rates of Type 3 and Type 6 variables were also observed in patients with axSpA (p=0.004, p=0.002, respectively). We further adjusted the analyses by the SPARCC SIJ inflammation scores since differences in these were found among the two groups [1], and similar differences in biomarker levels were found, indicating that the relationship between the level of biomarkers and the SPARCC SIJ inflammation scores was independent between the two groups.

Conclusion:

Biomarkers of type I, III, IV and V collagen and a CRP-metabolite showed an altered turnover in patients with axSpA compared with the control group including subjects with or without buttock or pelvic pain attributable to other reasons. Such biomarkers may be used in combination with MRI or independently to separate patients with axSpA from other back pain conditions.

References:

[1]Seven, S., Østergaard, M., Morsel-Carlsen, L., Sørensen, I. J., Bonde, B., Thamsborg, G., ... & Pedersen, S. J. (2019). Magnetic Resonance Imaging of Lesions in the Sacroiliac Joints for Differentiation of Patients With Axial Spondyloarthritis From Control Subjects With or Without Pelvic or Buttock Pain: A Prospective, Cross-Sectional Study of 204 Participants. Arthritis & Rheumatology, 71(12), 2034-2046.

Acknowledgements:

The study was supported by Innovation Fund Denmark, Rigshospitalet and the Danish Rheumatism Association (grant no. R102-A2132-B98, R159-A5061 and R150-A4467-B98).

Disclosure of Interests:

Helena Port Employee of: Industrial PhD student at Nordic Bioscience and University of Copenhagen, Signe Holm Nielsen Employee of: Full time employee at Nordic Bioscience, Joseph Blair Employee of: Full time employee at Nordic Bioscience, Sofie Falkenløve Madsen Employee of: Full time employee at Nordic Bioscience A/S, Anne-Christine Bay-Jensen Shareholder of: Nordic Bioscience A/S, Employee of: Full time employee at Nordic Bioscience A/S, Morten Karsdal Shareholder of: Nordic Bioscience A/S, Employee of: Full time employee at Nordic Bioscience A/S, Sengül Seven: None declared, Inge Juul Sørensen: None declared, Lone Morsel-Carlsen: None declared, Mikkel Østergaard: None declared, Susanne Juhl Pedersen: None declared

Peripheral Enthesitis Detected by Ultrasonography in Patients With Axial Spondyloarthritis-Anatomical Distribution, Morphology, and Response to Tumor Necrosis Factor-Inhibitor Therapy

Objectives: To investigate the anatomical distribution, morphological abnormalities and response to adalimumab therapy of ultrasound(US)-detected peripheral enthesitis in patients with axial spondyloarthritis (SpA).

Methods: In a randomized, placebo-controlled, double-blinded, investigator-initiated trial (NCT01029847), patients with axial SpA according to the Assessment of Spondyloarthritis International Society criteria were randomized to subcutaneous adalimumab 40 mg every other week or placebo from baseline to week 6. From week 6 to 24, all patients received adalimumab 40 mg every other week. Of 49 patients enrolled, 21 patients participated in our observational US sub-study. US assessment applying the OMERACT US definitions for enthesitis of 10 peripheral entheseal regions of the upper and lower extremities and clinical examination were performed at baseline, weeks 6 and 24. US was performed by one experienced investigator. Hypo-echogenicity, increased thickness and Doppler activity of the enthesis were considered signs of active inflammation, whereas insertional bone erosions, intratendinous calcifications, and enthesophytes were regarded as signs of structural lesions.

Results: Enthesitis on US was mostly present in the lower limbs, especially in the Achilles tendon (81%), the quadriceps tendon (62%), and the greater femoral trochanter (52%). Structural lesions were predominant (38 vs. 12% of examined entheses with inflammatory changes), particularly in the entheses of the lower limbs, and exhibited no change during treatment.

Conclusion: US-detected structural lesions were common while inflammatory lesions were relatively rare in patients initiating adalimumab due to axial SpA. Structural lesions did not appear to change during 24 weeks follow-up, suggesting that these lesions may not be helpful outcome measures in short-term clinical trials.

THU0541 ANATOMICAL LOCATION OF SACROILIAC JOINT MRI LESIONS IN PATIENTS WITH AXIAL SPONDYLOARTHRITIS, POSTPARTUM WOMEN, PATIENTS WITH DISC HERNIATION, CLEANING STAFF, RUNNERS AND HEALTHY PERSONS

Background:

Bone marrow edema (BME) on sacroiliac joint (SIJ) MRI is central in the Assessment of SpondyloArthritis International Society classification criteria for axial spondyloarthritis (axSpA). However, BME can be seen in other conditions and healthy persons. The presence of structural lesions may contribute to diagnosing axSpA.

Objectives:

To investigate the location and distribution of SIJ MRI lesions in patients with axSpA and disc herniation, women with and without post-partum pain (PPP), cleaning staff, runners, and healthy persons.

Methods:

In a prospective cross-sectional study of 204 participants, MRI of the SIJs was evaluated by two readers. MRI images were scored according to the SPARCC SIJ Inflammation1and Structural (SSS)2lesion definitions. Based on concordant reads, lesions were analysed according to location (unilateral/bilateral SIJ, upper/lower sacral/iliac quadrant/joint half, anterior (slice1-3)/central (slice 4-6)/posterior (slice 7-9) SIJ sections.

Results:

BME was present in nearly all groups, in all quadrants, and primarily in the anterior SIJ section (Figure 1), but rarely as a bilateral feature, except in axSpA and women with PPP (Table 1). Fat lesion (FAT) was mainly found in axSpA, in all slices, and mostly bilaterally in the sacrum. In the other groups FAT was primarily located in the anterior and central SIJ sections. Sclerosis was only seen in the ilium, and was present in most groups, particularly in women with PPP, often bilaterally. Erosion was only seen in women with PPP (mostly unilaterally) and in axSpA (mainly bilaterally in the ilium). Backfill and ankylosis were only seen in axSpA.

Table 1.

Participant characteristics and distribution of lesions – unilaterally/bilaterally in iliac/sacral quadrants

AxSpAWomen with post-partum painWomen without post-partum painDisc herniationCleaning staffLong distancerunnersHealthy menNumber of participants41461425262329Age30.9 (6.4)32.6 (3.3)*33.1 (4.1)35.2 (5.7)**39.1 (4.6)***32.7 (6.2)30.9 (6.4)Male sex630***0***440***78100***Low back pain VAS (0-10)3.8 (2.8)5.5 (2.4)**0.4 (0.7)***5.5 (2.4)*0.8 (1.8)***0.2 (0.5)***0.1 (0.3)***HLA-B27 positive8111***7***0***0***4***14***C-Reactive Protein >3 mg/l5917***21**20**15**17**3***Quadrant:UNI / BIUNI / BIUNI / BIUNI / BIUNI / BIUNI / BIUNI / BIBMEIliumUpperLower27 / 722 / 1711 / 915 / 130 / 021 / 00 / 00 / 00 / 40 / 40 / 04 / 00 / 00 / 0SacrumUpperLower29 / 2224 / 2017 / 99 / 929 / 04 / 04 / 04 / 04 / 00 / 00 / 00 / 00 / 00 / 0FATIliumUpperLower20 / 1717 / 292 / 00 / 07 / 07 / 04 / 04 / 00 / 00 / 00 / 00 / 00 / 70 / 3SacrumUpperLower22 / 4417 / 422 / 42 / 20 / 74 / 70 / 40 / 00 / 00 / 04 / 04 / 03 / 33 / 3SclerosisIliumUpperLower5 / 20 / 04 / 49 / 90 / 77 / 04 / 40 / 44 /415 / 00 / 04 / 03 / 70 / 0SacrumUpperLower0 / 00 / 00 / 00 / 00 / 00 / 00 / 00 / 00 / 00 / 00 / 00 / 00 / 00 / 0ErosionIliumUpperLower22 / 2417 / 244 / 02 / 20 / 00 / 00 / 00 / 00 / 00 / 00 / 00 / 00 / 00 / 0SacrumUpperLower10 / 522 / 22 / 02 / 20 / 00 / 00 / 00 / 00 / 00 / 00 / 00 / 00 / 00 / 0

Values are % or mean (SD)

Mann-Whitney test was applied, tests are patients with axSpA compared with all other groups. P<0.05*; p<0.01**; p<0.001***

BI: bilateral; BME: Bone marrow edema; FAT: fat lesion; HLA-B27: Human Leukocyte Antigen B27;UNI: unilateral; VAS: Visual Analogue scale

Conclusion:

Typical locations of common SIJ lesions in axSpA and non-axSpA were reported. In non-axSpA, except women with PPP, bilateral as well as posterior lesions were rare, while backfill and ankylosis were absent.

References:

[1]Maksymowych et al,Arthritis Rheum, 2005

[2]Maksymowych et al,J of Rheumatol,2015

Acknowledgments:

Disclosure of Interests: Sengül Seven Grant/research support from: Novartis, Mikkel Ǿstergaard Grant/research support from: AbbVie, Bristol-Myers Squibb, Celgene, Merck, and Novartis, Consultant of: AbbVie, Bristol-Myers Squibb, Boehringer Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo Nordisk, Orion, Pfizer, Regeneron, Roche, Sandoz, Sanofi, and UCB, Speakers bureau: AbbVie, Bristol-Myers Squibb, Boehringer Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo Nordisk, Orion, Pfizer, Regeneron, Roche, Sandoz, Sanofi, and UCB, Lone Morsel-Carlsen: None declared, Inge Juul Sørensen: None declared, Birthe Bonde: None declared, Gorm Thamsborg: None declared, Jens Jørgen Lykkegaard: None declared, Susanne Juhl Pedersen Grant/research support from: Novartis

Interrelation between some butterflies and plant associations (Turkey)

The butterfly fauna in Ordu province (N-Turkey) was determined in this study. Their relations with the phytosociological associations found in the zone were evaluated and the Lepidoptera taxa in these units were presented. The numbers of determined taxa in each plant association are Castanea-Carpinus-Corylus (23), Fagus orientalis, Carpinus betulus and Picea orientalis Mixed Forest Zone (23), Subalpine Zone (Rhododendron luteum-Vaccinium myrtillus) (25), Lower Alpine Zone (Festuca lazistanica ssp. giresunica) (20), Mid-alpine Zone (Festuca lazistanica ssp. giresunica) (13). Fifteen taxa are new for Ordu province.