Serum BAFF and thyroid autoantibodies in autoimmune thyroid disease

Background This study investigated the association of serum B-lymphocyte activating factor (BAFF) levels with autoimmune thyroid disease (AITD) in a Chinese population. Materials and methods We enrolled 221 patients with AITD [170 patients with Graves' disease (GD), 51 patients with Hashimoto's thyroiditis (HT)], and 124 healthy controls. Serum BAFF levels, thyroid function and thyroid autoantibody (TAb) levels, including of thyroid-stimulating hormone receptor antibody (TSHRAb), anti-thyroid peroxidase antibody (Anti-TPO Ab), and antithyroglobulin antibody (ATA), were measured at baseline. Results Serum BAFF levels were higher in the GD, HT, and AITD groups than in the control group. Significant correlations were observed between BAFF and TSHRAb levels (r = 0.238, p = 0.018), between BAFF and Anti-TPO Ab levels (p = 0.038), and between BAFF and ATA titers (p = 0.025) in women but not in men. In addition, serum BAFF levels were significantly associated with free thyroxine (r = 0.430, p = 0.004) and TSHRAb (r = 0.495, p = 0.001) levels in women with active GD but not in those with inactive GD. Conclusions Serum BAFF levels are increased in GD, HT, and AITD. The correlation between serum BAFF and TAb levels exhibits a dimorphic pattern, particularly in active GD.