IL18 and systemic lupus erythematosus: Besides, Asian, White, Arab and mixed SLE patients all exhibited elevated IL-18 level in comparison with healthy controls except for Latin American patients (SMD = 1.48, 95% CI [0.97–1.98]; SMD = 1.68, 95% CI [0.94–2.42]; SMD = 2.57, 95% CI [1.36–3.78]; SMD = 0.71, 95% CI [0.46–0.95]; SMD = 0.61, 95% CI [− 0.12 to 1.35]).