The effect of auranofin and sulphasalazine therapy on circulating levels of interleukin 6 in rheumatoid arthritis patients

Serum levels of interleukin 6 (IL-6), primarily a macrophage derived cytokine and soluble interleukin 2 receptor (sIL-2R), a marker of lymphocyte activation are elevated in rheumatoid arthritis (RA). We have found that the second line drugs auranofin (AUR) and sulphasalazine (SASP) do not significantly alter circulating levels of sIL-2R implying that these durgs do not influence lymphocyte activity. The effect of AUR and SASP on IL-6 is not established. In RA patients we have investigated the effect of these second line agents on serum II-6 levels.

Using the B9 bioassay, serum IL-6 was sequentially measured at 0 and 12 weeks in RA patients treated with auranofin (n=26) or sulphasalazine (n=20). Clinical and laboratory indices of disease activity were also assessed. In patients receiving either AUR or SASP, serum IL-6 was significantly reduced. This reduction was parallelled by improvement in clinical indices of disease activity. AUR and SASP significantly reduce serum IL-6 levels in RA patients receiving these treatments. Combining one of these agents with a drug that also influences sIL-2R may be a more rational approach to combining second line therapy in RA.