Thrombocytopenia is common in patients with myelodysplastic syndromes (MDS) and immune destruction of platelets could be an important factor for its occurrence. We prospectively analyzed platelet-associated IgG (PAIgG) through platelet immunofluorescence test (PIFT), mean platelet volume (MPV), platelet size deviation width (PDW) and glycocalicin index (GCI) of 54 patients with MDS, classified according to the International Prognostic Scoring System (IPSS). Thrombocytopenia (platelet count<100×10(9)/L) was correlated with a higher amount of PAIgG, significantly higher MPV and increased GCI. In addition, worse prognosis IPSS groups were associated with a higher positivity of PIFT, which could be indicative of advanced disease.36554-9