Radiographic outcome after three years of patients with early erosive rheumatoid arthritis treated with intramuscular methotrexate or parenteral gold. Extension of a one-year double-blind study in 174 patients.

Objective: To compare the radiographic outcomes after 36 months in patients with early erosive rheumatoid arthritis (RA) who were treated with methotrexate (MTX) or gold sodium thiomalate (GSTM).

Methods: In a randomized, double-blind fashion, 174 patients from two centres were assigned to receive weekly intramuscular injections of either 15 mg MTX or 50 mg GSTM. After 12 months, the study was continued as an open prospective study for an additional 2 yr, administering the same amount of MTX and half of the GSTM dose. Radiographic outcomes were assessed by standardized methods in all patients at baseline and after 6, 12, 24 and 36 months.

Results: Intention-to-treat analysis showed that patients treated with MTX had higher radiographic scores and more erosive joints at all follow-up points. However, there was no statistically significant difference between the two treatment groups. The progression rate was significantly slower during the second and third years of follow-up in both groups. Baseline and time-integrated (area under the curve over 6 months) disease activity parameters were good predictors of radiographic outcome after 3 yr. Seropositivity was not an independent predictor of progression. However, patients who were positive for rheumatoid factor had higher time-integrated disease activity (with less response to treatment) and thus their disease was significantly more progressive.

Conclusion: Both of the disease-modifying compounds used in this study, MTX and GSTM, were able to reduce the slope of radiographic progression during 3 yr of follow-up. There was some advantage for parenteral gold but no significant intergroup difference.