Objectives: To assess serum interleukin-6 (IL-6) and interleukin-23 (IL-23) and their correlation with angiogenic cytokines and disease activity in ankylosing spondylitis (AS), psoriatic arthritis (PsA), and SAPHO syndrome.
Patients and methods: We studied 152 spondyloarthritis (SpA) patients: 69 PsA, 61 AS, 22 SAPHO, and 29 controls. We recorded age, sex, disease duration, and treatment. We assessed BASDAI, VAS, and PASI scores. Serum IL-6, IL-23, VEGF, EGF, FGFb, and FGFa levels were determined using ELISA. We estimated ESR and CRP.
Results: Serum IL-6 and IL-23 levels were higher in SpA than in control (P < 0.00001 and P = 0.0004, resp.). There was a positive correlation between serum IL-6 and CRP in AS (P = 0.000001), PsA (P = 0.000001), and SAPHO (P = 0.0003) patients. There was a positive correlation between serum IL-6 and ESR in AS (P = 0.000001), PsA (P = 0.002), and SAPHO (P = 0.02) patients. There was no correlation of serum IL-6 and IL-23 with VAS, BASDAI, and angiogenic cytokines in SpA.
Conclusions: Serum IL-6 but not serum IL-23 correlated with ESR and CRP in SpA. No correlation was found of serum IL-6 and IL-23 with VAS, BASDAI, and angiogenic cytokines.