OX40/OX4OL in systemic lupus erythematosus: association with disease activity and lupus nephritis

ABSTRACT

To evaluate the role of OX40/OX40L as markers of disease activity and nephritis in SLE patients. The study included forty SLE patients [38 females and 2 males]. They underwent full history taking, clinical examination, and routine laboratory investigations. Their disease activity was assessed according to the SLEDAI. Twenty age and sex matched subjects were included as controls. Patients were divided into two groups; first group included 20 patients with biopsy proven lupus nephritis [LN] and the second group included 20 patients without evidence of renal involvement. We assessed the percentage of OX40+CD4+lyrnphocytes by flowcytometry and serum soluble OX40L by ELISA in patients and controls. The percentage of OX40+CD4+ lymphocytes in SLE patients was significantly higher than controls. There was a highly significant increase in the percentage of OX40+CD4+lymphocytes among the patients with nephritis as compared to the patients without nephritis. It correlated significantly with s.creatinine and SLEDAI. Soluble serum OX40L was significantly higher in SLE patients as compared to controls and the level in patients with LN was statistically higher when compared to patients without LN. It showed positive significant correlation with s.creatinine but did not correlate with the SLEDAI. Our results suggest that the interaction between OX40 and its ligand play an important role in the pathogenesis of SLE. The expression of OX40 on CD4+T cells and the level of OX40L may act as markers of LN. Furthermore, measurements of the percentage OX40+CD4+T cells may serve as an indicator of disease activity in SLE patients