The number of CD4+CD45RO+CCR4+ lymphocytes of RA and PsA patients correlated strongly with the erythrocyte sedimentation rate (ESR) (r = 0.72, p = 0.0093) and C-reactive protein (CRP) (r = 0.77, p = 0.0043) (Figure 6), suggesting the proinflammatory role of these cells. Here, CRP is linked to rheumatoid arthritis.