The effect of gold treatment on monocyte interleukin-1 production in rheumatoid arthritis. A prospective study.

Monocyte interleukin-1 (IL-1) production in vitro was studied in 49 patients with rheumatoid arthritis (RA) and 31 controls. Twenty-six of the RA patients were studied prospectively for up to 12 months after beginning chrysotherapy. About half of the patients (group 1) exhibited pretreatment levels of monocyte IL-1 secretion (as measured by bioassay or B-IL-1) significantly higher than that of the controls. Immunoreactive IL-1 (IR-IL-1) levels, however, were similar to controls. Clinical improvement in this group of patients was modest and transient but could be associated with a fall in the level of IL-1 (B-IL-1 and IR-IL-1) secretion. Other RA patients (group 2) appeared to have normal or reduced pretreatment levels of IL-1 secretion. Chrysotherapy resulted in significant clinical improvement within 3 months, and this was associated with an increase in IL-1 (both B-IL-1 and IR-IL-1) secretion by the patients' blood monocytes to normal or supranormal levels. Thus these two groups of RA patients (which differed only in the average duration of disease) had different prognoses in relation to chrysotherapy and the effect of chrysotherapy-induced remission on monocyte IL-1 secretion was opposite. These results suggest that monocyte IL-1 production in vitro reflects changes secondary to the anti-rheumatic effects of chrysotherapy.