Abstract: It is an awkward issue to treat systemic lupus erythematosus(SLE)in patients with corticosteroid unresponsiveness.Recently,P-glycoprotein(P-gP)and macrophage migration inhibition factor (MIF)have been clearly linked to the modulation of corticosteroid sensitivity.The following two mechanisms seem to be involved in corticosteroid unresponsiveness.First,over-expression of P-gp on activated peripheral lymphocytes can cause the exclusion of intercellular corticosteroid from lymphocytes.Second,the expression Of MIF.which exerts a potent antagonistic effect on corticosteroid suppression of immune-mediated inflammation.is increased in patients with SLE.It may restore the sensitivity to corticosteroid to down-regulate or suppress the expression of P-gp and MIF in patients with SLE.