FRI0298 Altered frequencies of circulating innate lymphoid cells and its subsets are correlated with disease activity in systemic lupus erythematosus patients
Authors: Y. Jiang, Y. Zhao, Y. Liu, X. Mo
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> Systemic lupus erythematosus (SLE) is a chronic, multisystem autoimmune disorder with a heterogeneous clinical manifestations that results from abundant immunological abnormalities. Innate lymphoid cells (ILCs), one subset of the innate immune cells, are divided into cytotoxic ILCs (namely natural killer cells) and non-cytotoxic ILCs (namely helper-ILCs). Non-cytotoxic ILCs are composed of three groups, group 1 ILCs, group 2 ILCs and group 3 ILCs, based on depended transcription factors and producing cytokines. So far, alterations of ILCs and their subsets have been reported in some autoimmune diseases except SLE. <h3>Objectives</h3> To visualise differences in frequencies of ILCs and their subsets in the peripheral blood of patients with SLE and healthy controls in Chinese Han population. <h3>Methods</h3> Peripheral blood mononuclear cells (PBMCs) was obtained from twenty-five SLE patients and twelve healthy controls and were stained with antibodies to CD45, lineage (CD3, CD19, CD123, CD11c, CD14, CD16, CD34, CD94, and FcεRIα), CD4, CD8, CD127, CD117, CRTH2 and NKp44. Circulating total ILCs and its subsets were identified by flow cytometry. The associations between disease activity and all the detected cells were evaluated using the Pearson or Spearman correlation coefficient. <h3>Results</h3> Increased frequencies of ILC2 and ILC3 were observed in patients compared to controls, while decreased frequency of ILC1 was found in patients compared with controls (p=0.008, p=0.004, and p=0.006, respectively). We also found the expression of T cell surface markers, CD4 or CD8, on ILCs and their subsets. The results showed that decreased frequencies of CD4<sup>+</sup>CD8<sup>+</sup> ILCs, CD4<sup>+</sup>CD8<sup>-</sup>ILC1, CD4<sup>+</sup>CD8<sup>+</sup> ILC2, CD4<sup>+</sup>CD8<sup>-</sup> ILC2, and CD4<sup>+</sup>CD8<sup>-</sup>CD336<sup>-</sup> ILC3 were found in patients compared with healthy controls (p=0.001, p=0.017, p=0.001, p=0.004, and p=0.002, respectively). Furthermore, frequencies of CD4<sup>+</sup>CD8<sup>+</sup> ILCs and CD4<sup>+</sup>CD8<sup>+</sup> ILC2 were positively correlated with the SLEDAI-2000 score (r=−0.548, p=0.005 and r=−0.613, p=0.001, respectively). Frequencies of CD4<sup>-</sup>CD8<sup>+</sup> ILCs and CD4<sup>-</sup>CD8<sup>+</sup> ILC1 were positively related with serum C3 level (r=0.519, p=0.008 and r=0.528, p=0.007, respectively), and were positively related with serum C4 level (r=0.623, p=0.001 and r=0.643, p=0.001, respectively). <h3>Conclusions</h3> In the present study, we demonstrated that frequencies of circulating ILCs and its subsets were altered in SLE patients and some subpopulations were negatively correlated with SLE disease activity. <h3>References</h3> [1] Shikhagaie MM, Germar K, Bal SM, Ros XR, Spits H. Innate lymphoid cells in autoimmunity: emerging regulators in rheumatic diseases. Nature reviews. Rheumatology2017;13:164–173. doi:10.1038/nrrheum.2016.218 [2] Morel L. Immunometabolism in systemic lupus erythematosus. Nature reviews Rheumatology2017;13:280–290. doi:10.1038/nrrheum.2017.43 <h3>Disclosure of Interest</h3> None declared