Inhibition of cytokine secretion in SR and SS groups. Percentage of inhibition of (a) TNF-α, (b) IL-12 and (c) IFN-γ cytokine secretion after PBMC incubation in RPMI with PHA plus 10-6 M dexamethasone in normal controls, SS patients and SR patients. Calculation formula of percentage inhibition of cytokine secretion by steroid was described in Materials and Methods. *P < 0.01, vs normal group, △ P < 0.01, vs SS group. (solid circle is outliers, and hollow circle is extreme values). IFN = interferon; IL = interleukin; PBMC = peripheral blood mononuclear cells; SR = steroid-resistant; SS = steroid-sensitive; TNF = tumour necrosis factor.