Aims: The link between inflammation and platelet activation was already proven. Only a few studies have been reported using platelet indices (platelet count (PC), mean platelet volume (MPV) and platelet distribution width (PDW)) as an indicator of acute phase response for assessment of disease activity. The aim of this study was to evaluate the PC, MPV and PDW trends in patients with rheumatoid arthritis (RA) comparing with control group. We also investigated whether these parameters were associated with disease activity score (DAS28-CRP) in RA patients. Materials and methods: Ninety consecutive RA patients fulfilling American College of Rheumatology criteria (RA group) and 52 rheumatic disease free participants (control group) were included this study. PC, MPV and PDW values of RA group compared with controls. Correlation tests were used in order to evaluate the relationship between the DAS28-CRP scores and PC as well as MPV and PDW. Results: We found significantly higher MPV and lower PDW values in the RA group when compared with controls. There were negative correlations between DAS28-CRP and MPV (r=-0,231, p=0,029) also PDW (r=-0,216, p=0,041) while correlation between DAS28-CRP and platelet count was not significant statistically. Conclusion: This study demonstrated that platelet indices such as MPV and PDW may provide helpful information for assessment of disease activity in patients with RA
