Systemic Lupus Erythematosus In The Expression Of Cytokines

Systemic lupus erythematosus (SLE) is a life-threatening autoimmune syndrome, with the features of humoral immune dysfunctions. The definate etiopathogenesis of SLE remains unclear. It is known that the autoantibody production by B lymphocytes is driven by T lymphocytes, although there is no distinct concept on the details of interaction between T and B cells in SLE. The cytokines scereted by T cells might act on B cells. However, it is controversial about the cytokine levels in SLE. One of the reasons is the effect by some factors existing in patients'sera or by different stimulants used in cytokine detection.The present study applys reverse transcription-polymerase chain reaction (RT-PCR ) technique to semiquantitatively analyse the Th1/Th2 type cytokine (IL-2, IFN γ / IL-6, IL-10) mRNA expression in untreated SLE patients. The total RNA was extracted from freshly isolated patients' peripheral blood mononuclear cells (PBMC), without any stimulation. Then, cDNA was synthesised from oligod(dT) T-primed RNA with reverse transcriptase. The target sequences for cytokines were amplified with β-actin, an internal reference material.PCR products were analysed by electrophoresis on 2% agar gel and photographed. The amount of each band was determined by densitometry. The data were compaired with normal controls,and statistically analysed. The results showed that the expression of Th2 type cytokines (IL-6, IL-10) were significantly increased in SLE patients, whereas the expression of Th1 type cytokine(IL-2, IFNy) markedly reduced. These results indicate that the imbalance of Thl/Th2 type cytokines may contribute to the pathogenesis of SLE, and the T lymphocyte might activate B lymphocyte through Th2 type cytokines driving autoantibody production.