The results revealed that, in comparison with RA patients in Tsukuba, those in Karuizawa showed a significant increase in cTh1, cTfh1, and Tph cells, and significant decrease in cTh17, cTh17.1, and CD8+ Treg in T cell subpopulations, and a significant increase in DNB, DN1, DN2, and class-switched memory B cells, and a significant decrease in unswitched memory B, naïve B cells, and ABCs in B cell subpopulations. Here, CD8A is linked to rheumatoid arthritis.