Abstract: Objective To analyze Th1/Th2subsets and their regulatory cytokines and cytokine r eceptors in recent onset SLE patients to determi ne the cause of immunological imbala nce in SLE.Methods Th1/Th2 cells were detected quantitatively by flow cytometry in patients with recent-onset SLE(n=35)and the controls(n=10).At the same time,IL-12,IL-12Rβ₂ and IL-18,IL-18R mRNA expression we re tested by ABI7700 real time PCR in SLE patients(n=38/42)and the controls(n=28).Results No difference was found in Th1/Th2 ratio between SLE patients and the controls(P>0.05).However,Th1was decreased significantly in S LE patients than that in the normal controls(P<0.05).The cytokines including IL-12P35,IL-12P40、IL-18and their respective receptors IL-12Rβ₂,IL-18R and IL-12P35/IL-10、IL-18/IL-10 were all significantly decreased in SLE group than those in the controls(P<0.05all).SLE patients with facial erythema presented significantly lower Th1/Th2 ratio and lower IL-12P35 mRNA exp ression than the controls did.Signi ficantly high IL-12P40 expression a s well as low IL-12P35 expression were found in SLE patients with positive RNP.Conclusions SLE is a disease with Th2 predominance due to low Th1 subset and decreased expressions of IL-12 and IL-12Rβ₂,IL-18 and IL-18R mRNA.SLE patients with facial erythema and positive RNP may be the special subtype of SLE,for they have different Th distribution and the particular imbalance in cytokines expression.

Key words: Lupus erythematosus,systemic, Th1cells, Th2cells, Interleukine 12, I nterlukine 18, receptors,interleukine