The cut-off value of IPF on the basis of grades thrombocytopenia for differentiating IPD from DPP: platelet count <100 000 / µL was 7.50% (with a sensitivity of 77.30% and specificity of 70.45%); 50 000 ≤platelet count <100 000 / µl was 5.77% (with a sensitivity of 82.4% and specificity of 72.2%); 20 000 ≤ platelet count <50 000 / µL was 9.3% (with a sensitivity of 72% and specificity of 66.7%); platelet count < 20 000 was 10.6% (with a sensitivity of 81.2% and specificity of 73.3%).