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 Behçet'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)-α and the soluble cytokine receptors sCD30, sCD163, sgp130, sIL-6 receptor-α (sIL-6R), sTNFRI and sTNFRII.
Results: TNF-α 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-α and sTNFRII/TNF-α 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-α ratios than nongranulomatous uveitis.