ITGB2 and rheumatoid arthritis: Concerning the role of LFA-1 in other autoimmune manifestations in humans, an elevated expression of LFA-1 on T cells was shown to correlate with the severity of systemic sclerosis, systemic lupus erythematosus (SLE) [263], rheumatoid arthritis (RA), and autoimmune thrombocytopenia [264,265].