Protein array analysis of serum cytokines in collagen-induced arthritis rats

Objective This study is undertaken to evaluate the changes of serum cytokine levels in different stages of collagen induced arthritis(CIA)rats,to search for the specific proteins related with rheuma- toid arthritis(RA)pathogenesis and inflammation,and to explore the mechanism of RA pathogenesis.Methods Rat cytokine antibody array coated with 19 specific cytokine antibodies was used to examine serum samples at peak and late stage of CIA rats,and were compared to normal cytokine levels.At the same time,ELISA assay for serum TNF-αproduction was used to verify the array results.Results Among the target cytokines,10 up- regulating cytokines were kept in high expression in different phases of disease,while 1 showed significant change only at the peak of disease.There was no downregnlating cytokines in the results.Serum TNF-αassay results were consistent to the array results.Conclusion Cytokines show different expression in CIA at differ- ent stages,and specific cytokines can be used as the candidates to further study of the RA pathogenesis.This study also provides molecular makers for early diagnosis.