Background & Objective: Interleukin 37 (IL-37) is an important regulator of
the anti-inflammatory T-cell response. In this study, we investigated its expression and
function in peripheral blood mononuclear cells (PBMCs) of patients with HLA-B27
associated acute anterior uveitis (AAU) and idiopathic AAU.
Methods: 15 patients with HLA-B27-associated AAU, 10 patients with idiopathic AAU
and 22 controls were recruited to this study from August 2013 to December 2016.
Complete ophthalmological examinations were performed and clinical features were
clearly documented. Blood samples were collected and peripheral blood mononuclear
cells were extracted. IL-37 messenger RNA (mRNA) and protein expression in peripheral
blood mononuclear cells (PBMCs) were examined by performing RT-PCRs and western
blot, respectively. Cytokines in the supernatants of stimulated dendritic cells (DCs) with
IL-37 were assayed by multiplex immunoassay.
Results: An increased level of IL-37 mRNA and protein expression by PBMCs was
found in the patient group with clinically active AAU compared to controls. There was no
significant difference in IL-37 mRNA and protein expression levels between HLA-B27
associated AAU and idiopathic AAU. IL-37 significantly inhibited the production of IL-1β,
IL-6, IL-10, IL-21, IL-23, TNF-α and IFN-γ. IL-37 levels of mRNA and protein expression
showed a significant positive correlation with disease activity.
Conclusions: Elevated IL-37 expression is associated with disease activity in HLA-B27
associated AAU and idiopathic AAU. IL-37 can inhibit proinflammatory cytokine
productions in AAU. Manipulation of IL-37 may offer a new therapeutic target for these