IL6 and rheumatoid arthritis: In an in vivo confocal microscopy study, Villani et al. found that the dendritic cell density of the cornea and levels of interleukin-1α and interleukin-6 of tear fluid were significantly reduced by systemic prednisone and methotrexate in RA patients with secondary SS, but this finding was not observed in those without SS [37].