PLASMA REACTIVE NITROGEN INTERMEDIATE LEVELS IN PATIENTS WITH CLINICALLY ACTIVE RHEUMATOID-ARTHRITIS

We studied reactive nitrogen intermediate levels in 31 patients with a ctive rheumatoid arthritis (RA) taking indomethacin and 20 healthy con trols using nitrite and citrulline levels, measured by spectrophotomet ry, as markers. Twenty patients with RA were followed up after 4 and 8 wk of treatment with additional therapy in the form of methotrexate. Mean nitrite levels in 31 patients were 0.94 +/- 0.41 mu mol/ml and 20 controls it was 1.18 +/- 0.99. After treatment with methotrexate for 4 and 8 wk the levels were 0.9 +/- 0.45 and 1.25 +/- 1.15 mu mol/ml, r espectively. Mean citrulline levels in all patients was 1.68 +/- 0.11 and controls was 1.39 +/- 0.6 mu mol/ml. Following therapy with methot rexate for 4 and 8 wk the levels were 1.40 +/- 0.49 and 1.40 +/- 0.51 mu mol/ml, respectively. It is possible that serum levels of these pro ducts may not reflect alterations in the synovial fluid levels. Altern atively, whatever lowering may have been achieved by the anti-inflamma tory effect of the therapy may have been countered by drug derived fre e radicals.