Abstract: Objective To analyze the characteristics of common rheumatic immune diseases such as rheumatoid arthritis （RA）, ankylosing spondylitis （AS）, osteoarthritis （OA） and the changes of T lymphocyte subsets and Treg cells. Methods The adult cases of RA, AS and OA in the clinic of immunology and rheumatology of a hospital in Zhengzhou from January 1, 2017 to December 31, 2019 were taken as the research object （case group）, and a healthy control group was established. The levels of T lymphocytes and Treg cells in the two groups were detected for comparative analysis, and the case characteristics of the case group were descriptive analyzed. Results A total of 1 486 adult cases of RA, AS and OA were included, with a male-female ratio of 0.56∶1, aged 18-67 years, 18- 44 years old accounted for 35.5%. There were 327, 270, and 889 cases of RA, AS, and OA, respectively. The differences in the gender, age, and family history of the three common rheumatic immune disease cases of RA, AS, and OA were statistically significant （P<0.05 or P<0.01）. The differences between T lymphocyte subsets and Treg cells in RA, AS, OA cases and healthy people were statistically significant （all P<0.01）. The CD4 and CD4/CD8 levels of RA, AS, and OA cases were all higher than those of healthy people, and the CD8 level was lower than that of healthy people. The CD4⁺T, CD25⁺T, CD4⁺CD25⁺T, and CD4⁺CD25⁺CD127-T levels of AS and OA cases were both higher than those of healthy people. Conclusion RA, AS and OA cases have certain characteristics of gender and age composition ratio. Different cases of rheumatic immune diseases have different levels of T lymphocyte subsets and Treg cells, and have varying degrees of immune dysfunction, which should be paid attention to.

Key words: Rheumatoid arthritis, Ankylosing spondylitis, Osteoarthritis, Immunology