Expression of the multidrug resistance glycoprotein 170 in the peripheral blood lymphocytes of rheumatoid arthritis patients. The percentage of lymphocytes expressing glycoprotein 170 is increased in patients treated with prednisolone

International audience; Abstract: The objective was to evaluate the expression of the multidrug resistance P-glycoprotein (P-gp) in peripheral blood lymphocytes (PBL) of patients with rheumatoid arthritis (RA). PBL from 68 RA patients and 44 controls were evaluated. RA patients had a mean disease duration of 10.7 yr, with a mean number of past resistances to DMARDs of 0.82, and were treated with NSAIDs (n = 34), DMARDs (n = 25) and prednisolone (n = 40). Fluorescence flow cytometry was used to assess P-gp membrane expression on PBL. In the RA group, the percentage of PBL expressing P-gp was higher in patients treated with prednisolone than in other patients [mean +/- S.D.: 10.7 +/- 15.8% vs…