Open Access

ARTICLE

Serum and urinary levels of IL-18 and its inhibitor IL-18BP in systemic lupus erythematosus

Paola Migliorini¹, Consuelo Anzilotti¹, Federico Pratesi¹, Paola Quattroni², Marco Bargagna², Charles A. Dinarello³, Diana Boraschi²

1 Clinical Immunology Unit, Department of Internal Medicine, University of Pisa, Pisa, Italy
2 Immunobiology Unit, Institute of Biomedical Technologies, National Research Council, Pisa, Italy
3 Dept. Infectious Diseases, University of Colorado Medical School, Denver, CO, USA

* Corresponding Author: P. Migliorini.

European Cytokine Network 2010, 21(4), 264-271. https://doi.org/10.1684/ecn.2010.0210

Accepted 07 August 2010;

Abstract

Overproduction of inflammation-related cytokines plays an important role in systemic lupuserythematosus (SLE). A crucial cytokine is IL-18, a member of the IL-1 family involved in the regulation ofboth innate and acquired immune responses. The aim of this study was to evaluate free IL-18 levels in theserum and urine of SLE patients, in order to establish their relationship with other biomarkers of disease activ-ity. Serum and urine levels of IL-18 and IL-18BP were measured by ELISA in 50 SLE patients and in32 healthy subjects; free IL-18 was calculated using the law of mass action. Serum levels of total IL-18,IL-18BP and free IL-18 were higher in SLE patients than in healthy controls. Total and free serum IL-18 levelswere higher in patients with active disease (with nephritis or active non-renal disease), and correlated with theECLAM score. Urinary levels of total and free IL-18 were higher in patients than in controls, but did not corre-late with disease activity. The data collected in this study show that increased levels of both IL-18 and its natu-ral inhibitor IL-18BP, characterise SLE. Despite the overproduction of IL-18BP, free IL-18 is still significantlyhigher in SLE patients than in controls, and its serum levels are a marker of disease activity.

---

Keywords

---