Background Ankylosing Spondylitis (AS) is characterized by abnormal immune responses including T cell activation. Although Cytotoxic T lymphocyte associated molecule-4 (CTLA-4) is involved in down-regulating immune responses, a soluble form of CTLA-4 (sCTLA-4) has been identified and was found at high levels in several autoimmune diseases. We aimed to determine the relation between the serum levels of sCTLA-4 and AS disease activity.
Objectives To evaluate the correlation between AS disease activity and sCTLA-4 level.
Methods In this work, 38 AS patients, 28 rheumatoid arthritis (RA) patients and 27 healthy controls were studied. AS who had never been treated with TNF antagonist were studied. sCTLA-4 cytokine level for each patient was determined with the ELISA method. ESR, CRP, demographic characteristics (gender, age, symptom duration) and standardized assessment tool (BASDAI) were recorded for each patient group. Obtained experimental data were statistically compared.
Results AS median age 39,37±12,11 years; %63,2 male, mean disease duration 19,00 (IQR:78). Compared to the RA group and healthy controls, high levels of sCTLA-4 were found in the AS group (p<0,001). Soluble CTLA-4 serum levels were not correlated with the clinical index of disease activity (p=0,370). A correlation was noted between the serum levels of ESH and BASDAI for the AS group (p=0,012).
Conclusions Our study investigates the role of sCTLA-4 levels in the pathogenesis of AS, and establishes a statistically meaningful difference between the serum levels of sCTLA-4 in AS patients, and those in RA patients and healthy controls (p<0,001). Early diagnosis is important in AS patients, and disease-spesific diagnostic tests are required for this purpose. Therefore, sCTLA-4 levels can be useful for the early diagnosis in AS patients. Consequently, further research is needed to explore the relation between cytokine levels and clinical findings for the early-stage AS patients.
Disclosure of Interest None declared