Author(s): Indah Fitri Lestari Saragih, Blondina Marpaung, Savita Handayani

Abstract: Systemic Lupus Erythematosus (SLE) is an autoantibodies process against the cell nuclei and immune complex that will activate the inflammatory system causing the excitatory threshold of platelet activation to be lower. Increase of significant mortality due to active disease (flare) SLE needs special attention. Study of the association of Mean Platelet Volume (MPV) and Platelet distribution width (PDW) as a marker to predict SLE activity was still controversial. On the other hand, MPV and PDW can be calculated easily in routine and low-cost laboratory tests. This study assesses the differences between Mean Platelet Volume (MPV) and Platelet Distribution Width (PDW) values in flare and non-flare groups in SLE patients. We found a significant difference in MPV values between flare compared to non-flares groups. Based on Receiver Operating Characteristic (ROC) curve showed an optimal cutoff value for MPV in the flare group is 9.15 fl and high sensitivity (90.6%). We recommend MPV value for initial screening in the detection of active (flare) SLE.