HLA-DRB5 and rheumatoid arthritis: HLA-DRB5-CCL+ macrophages, which were significantly upregulated in the ST of ACPA- RA, was more prone to utilize CCR8-CCL18, CCR1-CCL18, CCR1-CCL13, and CCR2-CCL13 to interact with ST T subsets (Fig. 10d).