Objective: To study interleukin (IL)-1beta levels in recent onset RA patients treated either with combination DMARD therapy (sulfasalazine, methotrexate, hydroxychloroquine) or a single DMARD therapy.
Methods: Serum IL-1beta levels were measured before the treatment and 6 months after the institution of either single or combination DMARD therapy using a high sensitivity ELISA method. Radiographic evaluation of the hands and feet was performed at 0 and 24 months.
Results: Significant correlations (r = 0.28, 95% CI 0.10-0.45) were found between IL-1beta levels measured at 0 and 6 months. The IL-1beta levels at 0 months correlated significantly (r = 0.23, 95% CI 0.03-0.4, p= 0.021) with the baseline number of eroded joints at 0 months but not with radiographic joint damage at 24 months. The baseline level of IL-1beta was a better indicator for the presence of eroded joints than the baseline level of serum CRP. No significant changes in IL-1beta levels were observed during the first 6 months of anti-rheumatic treatment in either group. No statistically significant difference between IL-1beta levels in the patients with or without the shared epitope could be observed.
Conclusions: The serum IL-1beta level is significantly associated with the presence of erosions at the onset of RA but its predictive value is attenuated or lost when single or combination DMARD medication is instituted. Measuring IL-1beta at the time of diagnosis in a single patient cannot be used to estimate the erosive nature of the disease or the prognosis.