 The study requires a blood sample from RA patients who have been on methotrexate therapy for a minimum of 3 months and are having an inadequate response to therapy. Physicians will then be provided with the results of the test indicating the methotrexate polyglutamate active metabolites of methotrexate levels in the patients red blood cells as a means to help determine whether a patients exposure to methotrexate has been optimized. 