CD4 and arthritic joint disease: Immunoprofiling of synovial fluid showed that the proportion of inflammatory IL-17-producing CD4+ T cells and amount of IL-17 were notably increased in synovial fluid with every recurrent flair, and correlated with the increase in number of synovial neutrophils, suggesting a potential role of T helper 17 (Th17) cells in neutrophil-driven inflammation during pseudogout arthritis.