Study Of Platelet Lysate Differential Protein In The Diagnosis Of Primary Immune Thrombocytopenia In Clinical Application

Objective: Primary immune thrombocytopenia (ITP) is a common hemorrhagicdisease, the pathogenesis of ITP is unknown, the diagnosis of ITP is givenpriority to exclusive method. At present, the laboratory diagnosis of ITP is mainlybased on bone marrow megakaryocyte counts, maturation disorder and the serumplatelet antibody, but the bone marrow megakaryocyte maturation disorderspecificity is poor,moreover the anti-platelet antibody is a polyclonal antibody, inaddition the immune phenotype comes in many forms. Therefore the existingtesting method is not only low positive rate but cannot also identify otherautoimmune disease caused by thrombocytopenia. In clinical diagnosis is verydifficult for ITP. We applied the surface enhanced laser desorption/ionization-time of flight-mass spectrometry (SELDI-TOF-MS) and protein chiptechnology to detect platelet lysate of ITP patients, secondary immunethrombocytopenia patients and secondary non-immune thrombocytopenia patientsand healthy people, in order to screen differential proteins and establish the ITPdiagnosis model. Methods: All the platelet lysate samples (including64cases ofITP,47cases of acute leukemia,26cases of aplastic anemia,26cases ofsystemic lupus erythematosus patients and42cases of healthy people) weredetected by SELDI-TOF-MS technology to generate the platelet protein massspectrum. Biomarker Wizard software3.1was adopted to analyze the dataderived from Proteinchip software. Used t test method to get the mean, standard deviation and P value. P value less than0.05was thought to be statisticallysignificant. The differential protein was screened. The diagnostic model of ITPwas established by the artificial neural network(ANN). Result: Themass-to-charge ratio (mass electron ratio, M/Z) for a range of2000to20000:1.ITP group compared with control group, there were four differential protein peaks(P<0.05),3549.17、7678.09higher expression in the ITP group and5328.29、7894.32lower expression.2. ITP group compared with secondary immunethrombocytopenia group (including SLE patients), there were four differentialprotein peaks (P <0.05), their M/Z is2276.15、3130.62、4521.60、5795.56respectively.Compared with secondary immune thrombocytopenia group, thefour differential protein lowly expressed in the ITP group.3. ITP group comparedwith secondary non-immune thrombocytopenia group (including acute leukemiapatients and aplastic anemia patients), the mass-to-charge ratio7955.22,9409.65expression difference was statistically significant (P <0.05)4. Secondaryimmune thrombocytopenia group compared with secondary non-immunethrombocytopenia group, the mass-to-charge ratio2842.32and9409.65expression difference was statistically significant (P <0.05), highly expressed insecondary immune thrombocytopenia group.5. ITP group, secondary immunethrombocytopenia group and secondary non-immune thrombocytopenia groupcompare, four differential protein peaks were screened,2276.15,3130.62,7955.22,9409.65, respectively.6. With the four differential protein which wasscreened through the ITP group compared with control group, ITP diagnosismodel one was established. This model was blind tested by the validation group one (including32cases of ITP patients and21cases of normal group) and yieldeda sensitivity93.3%, a specificity82.6%, a positive predictive value87.5%, anegative predictive value82.6%and a Youden’s index75.2%.7. With the fourdifferential protein which was screened through the ITP group compared withsecondary immune thrombocytopenia group and secondary non-immunethrombocytopenia group, ITP diagnosis model two was established. This modelwas blind tested by the validation set two (including32cases of ITP patients,13cases of SLE patients,24cases of AL patients and13cases of AA patients) andyielded a sensitivity of78.4%, a specificity of93.3%, a positive predictive valueof90.6%, a negative predictive value of84.0%, a Youden’s index of74.4%.Conclusion:1. ITP group and control group, the secondary thrombocytopenia(including secondary immune thrombocytopenia group and secondarynon-immune thrombocytopenia group) platelet lysate differential proteinexpression have statistical significance.2. SELDI-TOF-MS could be an effectivetool to seek biomarkers correlated with the ITP. The artificial neural networkmodel may have some clinical value for the diagnosis of ITP.