Circulating interleukin-23 levels in ankylosing spondylitis and their correlation with disease activity : A meta-analysis

Determination of IL-23 receptor expression and gene polymorphism (rs1884444) in Iranian patients with ankylosing spondylitis

BACKGROUND

Through investigating genetic variations, it has been demonstrated that single nucleotide polymorphisms (SNPs) in the IL-23 receptor (IL23R) gene have a critical role in the pathophysiology of ankylosing spondylitis (AS). Here, we investigated whether the IL23R variant (rs1884444) is associated with AS in the Iranian population.

METHODS AND MATERIAL

In this research, we analyzed rs1884444 in a group of 425 patients with AS and 400 matched controls. For DNA extraction, the phenol/chloroform technique was utilized. Peripheral blood mononuclear cells (PBMCs) were obtained from the whole blood of 39 patients and 43 healthy controls and total RNA was extracted. Genotyping was performed by amplification-refractory mutation system (ARMS)-PCR method. Afterward, the expression level of IL23R was analyzed by the real-time quantitative (Q)-PCR method.

RESULTS

We observed no significant association between the distribution of alleles and genotypes of rs1884444 and susceptibility to AS. In addition, the expression level of IL23R did not differ between PBMCs from AS patients compared to the control group (P = 0.167). Furthermore, the relative expression level of IL23R was positively correlated with the BASDAI (P < 0.01) and BASFI (P < 0.05) scores of the patients.

CONCLUSION

It appears that IL23R polymorphism (rs1884444) and the level of gene expression might not contribute to the susceptibility to AS in the Iranian population. The correlation of IL23R expression with the level of BASDAI and BASFI scores in patients may be due to the role of the IL-23/IL-23R signaling cascade in inflammation and exert a critical role in the development of AS.

Role of Metrology in Axial Spondyloarthritis: Does It Provide Unique Information in Assessing Patients and Predicting Outcome? Results From the British Society for Rheumatology Biologic Register for Ankylosing Spondylitis

OBJECTIVE

To determine among patients with axial spondyloarthritis (SpA) the factors associated with decreased spinal mobility and to determine whether poor mobility is a predictor of response to anti-tumor necrosis factor (anti-TNF) therapy.

METHODS

This was a prospective UK cohort study of persons meeting Assessment of Spondylarthritis international Society (ASAS) criteria for axial SpA. At recruitment, clinical and patient-reported factors independently associated with spinal mobility (measured by the Bath Ankylosing Spondylitis Metrology Index [BASMI]) were determined. Among those commencing anti-TNF therapy, factors that were independent predictors of response were determined using ASAS criteria, quality of life, and Ankylosing Spondylitis Disease Activity Score (ASDAS) response criteria.

RESULTS

A total of 1,960 participants were eligible; 70% were male and the median age was 48 years (interquartile range [IQR] 37,59), median BASMI score 3.6 (IQR 2.2, 5.3). Factors independently associated with poor spinal mobility were poorer function, meeting radiographic criteria for AS, longer symptom duration, higher levels of inflammation (measured by C-reactive protein level), older age, male sex, not being currently employed, and lower levels of education. For 51% of participants, the measured BASMI score was within 1 of that estimated. Poorer mobility (higher BASMI score) was an independent predictor of not meeting response criteria for ASAS 20% improvement (odds ratio [OR] per increasing score 0.80 [IQR 0.66, 0.98]), ASAS 40% improvement (OR 0.69 [IQR 0.50, 0.95]), and quality of life (measured by the Ankylosing Spondylitis Quality of Life Questionnaire) (β = 0.64 [IQR 0.26, 1.02]), but was not related to meeting ASDAS response criteria.

CONCLUSION

The BASMI score was estimated moderately well by other routinely measured factors in patients with axial SpA and was an independent predictor of response to biologic therapy for some, but not all, commonly used measures. Consensus around its role in disease monitoring and clinical decisions, particularly in the likely context of face-to-face consultations becoming less frequent, remains to be established.