Association of interleukin-36α gene expression in Egyptian patients with systemic lupus erythematosus with organ involvement and disease activity

Systemic lupus erythematosus (SLE) is a complex systemic autoimmune disease characterized by a wide spectrum of clinical manifestations with varying severity. The dysregulation of cytokines contributes strongly to disease pathogenesis. Recently, it has been shown that the imbalanced antagonist/agonist profile of interleukin (IL)-36 cytokines, might play a role in autoimmune disorders. Our aim is to investigate mRNA expression of Interleukin-36α (IL-36α) in the peripheral blood of Egyptian systemic lupus erythematosus (SLE) patients and its association with disease activity and organs involvement. We assessed the relative expression of IL-36α mRNA by real time polymerase chain reaction and the comparative CT method on the peripheral blood of 49 SLE patients, and 40 healthy controls. Patients were subjected to thorough history and clinical examination, in addition to routine hematological, biochemical, and serological studies. Disease activity was evaluated using the SLE Disease Activity Index (SLEDAI). The relative expression of IL-36α mRNA was significantly higher in SLE patients compared to healthy controls (4.3±2.9 vs 1, respectively, P<0.0001). Fold change of IL-36α expression was significantly increased in patients with moderate and high disease activity (SLEDAI>5) than patients with mild disease activity (SLEDAI≤5) (4.3±1.2 vs 2.7±2.0, respectively, P=0.006) and positively correlated with SLEDAI (r=0.505, P=0.001). Regarding major organ involvement, the mean±SD expression of IL-36α in patients with arthritis and mucocutaneous involvement was significantly higher compared to those without organ involvement (4.2±1.5 vs 2.8±1.8, P=0.039 and 4.1±1.4 vs 2.8±2.1, P=0.041, respectively). In conclusion, the IL-36α is significantly more expressed in SLE patients compared to healthy controls and correlated with SLE disease activity and arthritis. IL-36α expression could be a useful biomarker for SLE disease activity in Egyptian patients with SLE.