SIMULTANEOUS SALICYLATE CONCENTRATIONS IN SYNOVIAL FLUID AND PLASMA IN RHEUMATOID ARTHRITIS

Total, free (diffusible) and proteinbound salicylate concentrations were determined in synovial fluid samples obtained from 12 patients with rheumatoid arthritis, and compared with simultaneously obtained plasma concentrations. Free salicylate concentrations were essentially identical in the two fluids, implying complete equilibrium. Both the total and protein‐bound salicylate concentrations were consistently lower in the synovial fluids than in the corresponding plasmas; this difference may be explained by the lower albumin concentration in the joint fluid. Le concentrationes de salicylato total, libere (diffusibile), e ligate a proteina esseva determinate in specimens de fluido synovial obtenite ab 12 patientes con arthritis rheumatoide, e esseva comparate con ie concentrationes in simultaneemente obtenite specimens de plasma. Le concentrationes de libere salicylato esseva essentialmente identic in le duo fluidos, lo que implica complete equilibrio. Le concentrationes de salicylato total e de salicylato ligate a proteina esseva uniformemente plus basse in le fluidos synovial que in le correspondente plasmas; iste differentia pote esser explicabile per le plus basse concentration de albumina in le fluido del articulationes.