Abstract
Purpose Soluble cytokine receptors are potential biomarkers for immune activation and have a promising potential as immunotherapeutic agents. We investigated the levels of soluble cytokine receptors in aqueous humour (AH) samples from patients with specific autoimmune uveitic entities. Methods Patients with active uveitis associated with Behcet's disease (BD) (n = 13), sarcoidosis (n = 8), HLA-B27-related inflammation (n = 12), Vogt-Koyanagi-Harada (VKH) disease (n = 12) and control subjects (n = 9) were included. AH samples were analyzed with the use of multiplex assays for the proinflammatory cytokine tumour necrosis factor (TNF)-alpha and the soluble cytokine receptors sCD30, sCD163, sgp130, sIL-6 receptor-alpha (sIL-6R), sTNFRI and sTNFRII. Results TNF-alpha and soluble cytokine receptor AH levels were significantly higher in uveitis patients (n = 45) compared with controls (n = 9). When nongranulomatous uveitis (BD and HLA-B27-associated uveitis) was compared with granulomatous uveitis (sarcoidosis and VKH disease), the levels of sCD30 and sTNFRI/TNF-alpha and sTNFRII/TNF-alpha ratios were significantly enhanced in granulomatous uveitis. Finally, when comparing the profile in the specific uveitis entities, sCD30 levels were highest in patients with VKH disease. sgp130, sCD163, sIL-6R, sTNFRI and sTNFRII did not differ significantly between the four different clinical uveitic subgroups. Conclusions Soluble cytokine receptors are significantly upregulated in autoimmune uveitis. CD30(+)T cells might contribute to the inflammatory process in granulomatous uveitis, particularly in VKH disease. Granulomatous uveitis is also characterized by significantly higher sTNFRs/TNF-alpha ratios than nongranulomatous uveitis.