Cytokine Profile Rather Than T Regulatory Cells Correlate With the Pathogenesis of Vogt-Koyanagi-Harada (vkh) Syndrome

Abstract

Purpose: : Vogt-Koyanagi-Harada disease (VKH) is an autoimmune disease characterized by bilateral uveitis, meningitis, alopecia, vitiligo and perceptive deafness. Regulatory T cells have as well known suppressive and regulatory activity which has an important role in maintaining immune tolerance and also in controlling immune responses to infection, cancer and allergies. We proposed to investigate the percentage of T regulatory cells as well as the cytokine profile of PBMCs from patients with VKH.

Methods: : we obtained PBMCs from VKH patients and healthy controls and analyzed by flow cytometry the percentage of CD4⁺CD25^high, CD4⁺Foxp3⁺ and CD25⁺Foxp3⁺ T regulatory cells. Transcriptional level of Foxp3 expression was also assessed by real time quantitative PCR. In addition, the cytokine profile from supernatants of PBMC cultured with or without PHA was measured by ELISA.

Results: : Our results showed that VKH patients had no significant difference either in the percentage of CD4⁺CD25^high, CD4⁺Foxp3⁺ or CD25⁺FOXP3⁺ T cells nor in the expression Foxp3 mRNA levels when compared to healthy controls. On the other hand, VKH patients showed an increased production of the cytokines IL-4, IL-10, IFN-gamma and TGF-beta. Our data shows that in VKH syndrome, Treg cells seem not to have a central role for the pathogenesis of the disease, although we cannot exclude this possibility. On the other hand, the increase in TGF-beta and IL-10 levels observed in our patients may be correlated with the suppression of the autoimmune response and resolution of the disease.

Conclusions: : Thus, our findings may indicate that maybe other population of T cells, like Tr1 or Th3 cells rather than CD4⁺Foxp3⁺, may have a more relevant role in controlling the disease.

Keywords: inflammation • uvea • immunomodulation/immunoregulation