Relationship of serum s100a8-a9 levels with disease activity, radiological findings and laboratory parameters in patients with psoriatic arthritis

Objective: Our aim in this study was to measure serum S100A8 and S100A9 levels in PsA, a chronic inflammatory disease, to compare their levels with psoriasis patients and healthy controls and examine the relationship between clinical findings, laboratory parameters, radiological joint damage, disease activity scales. Materials and methods: In this cross-sectional study, a convenience sample of adults obtained from an outpatient clinic of a university hospital in Turkey between November 2021 and October 2022. The study included 62 patients who were diagnosed with PsA by meeting the classification criteria defined by the CASPAR (Classification Criteria for Psoriatic Arthritis), 54 patients who were diagnosed psoriasis and 30 healthy controls between the ages of 18-65, among the patients who applied to Düzce University Faculty of Medicine, Department of Physical Medicine and Rehabilitation. Demographic data such as age, gender, body mass index (BMI), education level, occupation of the PsA, psoriasis and control groups were recorded. In order to determine disease activity in the PsA patient group, DAPSA (Disease Activity for Psoriatic Arthritis) score, BASDAİ (Bath Ankylosing Spondylitis Disease Activity Index) score, visual pain scale (VAS) score, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) values were measured and recorded. MSHS (Modified Sharp-van der Heijde score), PASRI (PsA spondylitis radiology index) scores were measured and recorded in order to evaluate peripheral and axial radiological findings. PASI (Psoriasis Area Severity Index) was calculated and recorded to determine the degree of skin involvement in the PsA and psoriasis patient group. Serum S100A8 and S100A9 levels of the PsA, psoriasis and control groups were studied by enzyme-linked immunosorbent assay (ELISA) method. Results: The median serum S100A8 level of the PsA group was 43.2 ng/ml, the median serum S100A9 level was 34.7 ng/ml; median serum S100A8 level of the psoriasis group was 35.4 ng/ml, median serum S100A9 level was 51.4 ng/ml; The median serum S100A8 level of the control group was 54.0 ng/ml, and the median serum S100A9 level was 24.9. In the psoriasis group, the serum S100A8 level was statistically lower (p=0.03) and the serum S100A9 level was statistically higher (p<0.001) compared to the PsA and control groups. There was a statistically vii significant positive correlation between serum S100A9 level and number of tender joints (p=0.04), number of swollen joints (p=0.025) and DAPSA scores (p<0.05) in PsA patients. Statistical correlation between serum S100A8 level and number of tender joints (p=0.023), VAS-patient (p=0.003) and VAS-physician (p=0.014) values, DAPSA (p=0.037) and BASDAI (p=0.010) scores in the PsA group significant negative correlation was found. The median CRP value was 0.4 in the PsA group, 0.2 in the psoriasis group, and 0.2 in the control group. CRP values measured in PsA patients were significantly higher than in psoriasis patient (p=0.013) and healthy control (p=0.001) groups. There was no significant correlation between PASI scores and serum S100A8 and S100A9 levels in patients with PsA and psoriasis (p>0.05). There was no significant correlation between MSHS and PASRI radiological scores and serum S100A8 and S100A9 levels in the PsA group (p>0.05). A significant positive correlation was found between BMI and serum S100A9 level in psoriasis patients (p=0.039). Serum S100A8 and S100A9 levels in the PsA group; There was no significant correlation between serum S100A8 level and BMI in the psoriasis group (p>0.05). Conclusion: The correlation of S100A9 level with the disease activity parameters swollen, tender joint number and DAPSA in PsA suggests that S100A9 can be used in the evaluation of disease activity. However, the lack of significant difference in S100A9 levels between the control group and PsA group suggests that it cannot be used in the diagnosis of PsA. The significantly higher S100A9 level in the psoriasis group compared to the PsA and control groups suggests that S100A9 may play a role in the pathogenesis of psoriasis. The lack of correlation between S100A9 level and PASI scores in the PsA and psoriasis groups suggests that S100A9 may not be an appropriate biomarker in the evaluation of the severity of skin involvement. The fact that S100A8 level did not differ significantly between PsA and control groups suggests that S1008 cannot be used in the diagnosis of PsA. Different from the literature studies, the level of S100A8 was found to be significantly lower in the psoriasis group compared to the PsA and control groups in our study, and the negative correlation with disease activity parameters in the PsA group suggests that it may be a biomarker negatively correlated with disease activity. We think that further studies are needed on the factors affecting the level of S100A8 in body fluids and their functions. Key words: Psoriatic arthritis, Psoriasis, S100A8, S100A9, Disease Activity