PULSE METHYLPREDNISOLONE IN RHEUMATOID-ARTHRITIS - EFFECTS ON PERIPHERAL-BLOOD AND SYNOVIAL-FLUID NEUTROPHIL SURFACE PHENOTYPE

Objective. To determine the effects of a 1000 mg intravenous pulse of methylprednisolone (MP) on the expression of cell adhesion molecules o n peripheral blood and synovial fluid (SF) neutrophils in rheumatoid a rthritis. Methods, Fluorescent flow cytometric analysis was performed on peripheral blood neutrophils (n = 13 patients) and knee joint SF ne utrophils (n = 7 patients) prior and at 4 and 24 h after MP. Clinical and laboratory assessments of disease activity were performed. Results . There was marked improvement in all clinical scores at 24 h includin g a decrease in pain score (p < 0.0005), stiffness (p < 0.00005), join t tenderness score and modified Health Assessment Questionnaire (HAQ) (p < 0.005), and an increase in well being (p < 0.001). At 24 h there was a significant decrease in SF neutrophil counts to a mean (SEM) of 31.5% (15%) of baseline and an increase in peripheral blood neutrophil s to a mean (SEM) of 199% (25%) of baseline. Furthermore, a significan t decrease was observed in the expression of both structural and funct ional epitopes of CD11b (p < 0.05) and CD18 (p < 0.05) on SF neutrophi ls at both 4 and 24 h post-MP. There was also an increase in the expre ssion of L-selectin (CD62L), which approached significance (p = 0.01), but no significant effect on CD11a, CD44 and sialyl Lewis(x) (CD15s). Peripheral blood neutrophils showed decreased expression of CD11b (p = 0.1), CD18 (p = 0.07), and L-selectin (p = 0.09), which approached s tatistical significance without any associated effects on CD11a, CD15s , or CD44. Conclusion, MP is associated with a marked decrease in CD11 b and CD18 expression on SF neutrophils and, to a lesser extent, perip heral blood neutrophils. This may be due to decreased neutrophil activ ation as these cells traffic from the vasculature through the synovial membrane or to decreased activation in the synovial space.