The expression and clinical significance of different forms of LILRA3 in systemic lupus erythematosus

Objective: Our previous study has shown that functional leukocyte immunoglobulin-like receptors A3 (LILRA3) contributes to susceptibility and subphenotypes of systemic lupus erythematosus (SLE). However, the mechanism remains unclear. We aimed to evaluate the role of LILRA3 in SLE.

Methods: One hundred twenty-six SLE patients and 48 healthy controls were recruited in this study. Functional studies were performed using intracellular flow cytometry and ELISA.

Results: Both LILRA3 levels in serum and CD14⁺ monocytes were significantly elevated in SLE patients compared with healthy controls. Elevated LILRA3 level was found positively correlated with SLEDAI. Furthermore, more elevated LILRA3 levels were found in patients with higher SLEDAI, presence of lupus nephritis, and thrombocytopenia.

Conclusions: Both LILRA3 levels in serum and CD14⁺ monocytes significantly increased in SLE and positively correlated with disease activity and severity. The upregulation of LILRA3 expression may serve as a biomarker of disease activity and severity of SLE.

Key points: • LILRA3 contributes to susceptibility and subphenotypes of SLE; LILRA3 is elevated in SLE patients. • Increased LILRA3 correlated with disease activity and severity. • LILRA3 may serve as a biomarker of disease activity and severity of SLE.