PHILADELPHIA -- Two standard markers can identify early-stage rheumatoid arthritis patients whose disease is unlikely to respond to methotrexate alone, a researcher said here.
After 12 weeks of methotrexate treatment, levels of C-reactive peptide (CRP) and swollen joint counts predict with moderately good accuracy those who will have major disease progression if they stay on the drug as monotherapy, according Michael Weinblatt, MD, of Brigham and Women's Hospital in Boston.
Analysis of 169 patients in a previously conducted clinical trial showed that one-year radiographic progression on methotrexate monotherapy could be predicted correctly in about two-thirds of patients on the basis of CRP and swollen joint counts, Weinblatt told attendees here at the American College of Rheumatology's annual meeting.
Researchers identified two populations at the highest risk for major progression: those with 11 or more swollen joints at week 12 and CRP levels of 0.67 mg/dL or less; and those with higher CRP levels and at least two swollen joints.
The model had an overall sensitivity of 85%, Weinblatt said, with specificity of 60% and classification accuracy of 68%.
"Clinicians should know who's going to be a progressor because that could guide therapy," Weinblatt said.