Role of Th1/Th2 cytokines in the diagnosis and prognostic evaluation of ankylosing spondylitis.
Ankylosing spondylitis (AS), a progressive disease of the spine, manifests as peripheral arthritis with tendon and ligament inflammation that restricts activity. AS is a rheumatoid autoimmune disease although the rheumatoid factor is absent in patients with AS. It is characterized by inflammatory changes such as elevated levels of serum inflammatory factors. The roles of Th1 and Th2 cytokines in autoimmune diseases are well known. However, the roles of these cytokines in the diagnosis and prognosis of AS is poorly understood. The aim of this study was to investigate the roles of Th1/Th2 cytokines in the diagnosis and prognosis of AS. The BASDAI activity, BASFI functional index, BASMI measurement score, and the levels of CRP and ESR were measured during the treatment of patients with active AS. The levels of IFN-γ and TNF-α (Th1 cytokines) and IL-4 and IL-10 (Th2 cytokines) were quantified. The levels of IL-4 and IL-10 were significantly low in the serum of patients with active AS, who also had high IFN-γ and TNF-α levels compared to those in the control individuals (P < 0.05). After treatment, the levels of IL-4 and IL-10 increased while those of IFN-γ and TNF-α decreased compared to those in individuals with active AS (P < 0.05). The disease activity index correlated positively with levels of IFN-γ and TNF-α and negatively with levels of IL-4 and IL-10, but not with that of CRP or ESR. Changes in the levels of Th1/2 cytokines in patients with AS may reflect disease activity and prognosis.