The Test Method About Desialylation Of Platelet To Establish And Its Significance

BackgroundPlatelet transfusion is usually used in the treatment or prevention of bleeding blood diseases,especially in Autoimmune thrombocytopenia(ITP).It is a kind of complex participation of a variety of mechanisms. It is due to loss of tolerance with autoimmune platelet antigens,resulting in humoral and cellural immune.And the diseases can mediate platelet destruction and inhibition of platelet production.It is manifested in thrombocytopenia with or without mucocutaneous bleeding in clinically. The incidence of ITP is about 5-10/100,000 population,similar for men and women.Compared with men,women of childbearing age had a high incidence.At the same time,population over aged 60 had 2 times incidence rate than population below aged 60.In the treatment,the clinical found that some patients has not been alleviated after using corticosteroids,IVIG even splenectomy.There is always internal bleeding and even intracranial hemorrhage risk.It can detect specific autoantibodies which are anti-GPIbα and anti-GPⅡbⅢa from patients who has a poor treatment in the use of first-treatment. Currently pathogenesis of ITP considered that Fcγ receptor in macrophages binds these antibodies above platelet presence.At the end,platelets were cleared in the spleen.But glycoprotein desialylation by neuraminidase was considered to be the latest theory recently.The glycoprotein above the surface of platelet exposed βGN and galactose under the action of neuraminidase. After desialyation,the glycoprotein bind on αMβ2 integrin on kupffer cells and Ashwell-Morell receptor on hepatic cells.At the end,the desialyation platelets were cleared in the liver.ObjectiveFirstly,normal adult were selected in this subject.We researched different temperature and different time points are the factors whether would affect platelet desialylation or not.So we could establish the best test method about platelet desialylation.Secondly,we used the method to test platelet desialylation that are RCA% and ECL% in ITP.Thirdly,we used the MAIPA method to test specific autoantibodies in ITP.Finally,we analysis the reason of the ITP patients who has a poor treatment in the use of first-line treatment with platelet desialylation and specific autoantibodies.MethodsIn this subject,we selected 20 normal adults and researched the differences about RCA and ECL which are two factors of desialyation of platelets in different time periods(0,4,8,24 h) and different temperatures(4,25 ℃) with flow cytometry.The 20 normal adults came from our hospital medical center.Under this conditions, the best test method that could detect desialylation of platelets in 20 cases of Autoimmune thrombocytopenia(ITP) could be established at the end.20 cases of ITP were divided into effective responses to first-line treatment and invalid for first-line treatment.Grouping criteria is a 2012 edition of diagnosis and treatment of adult autoimmune thrombocytopenia from China expert consensus.In this consensus,complete response(CR) means platelets≥100×109/L and no bleeding after treatment.Effective(R) means platelets ≥ 30×109/L and the number of platelets increased 2 times than before.No response(NR) means platelets<30×109/L and the number of platelets can not increase 2 times than before or Patients are always bleeding.In this subject,CR and R belong to the group that effective responses to first-line treatment.And NR belong to another group.At the end,we used MAIPA method to detect specific autoantibodies in 29 ITP patients who were coming from our hospital.Results1) 20 normal subjects’ desialyation under different temperatures and different time points:we compared desialyation of platelet under different temperatures and different time points in 20 normal subjects.The results showed that the median of the desialylation of platelets(RCA % and ECL %) were not significant in 4 periods under 25 ℃,but showed a difference in 4 periods under 4℃.Under 4℃,the desialyation of 24 h points is difference with each other.The desialyation of 4 periods were no difference with each other under 25℃.The desialyation(RCA%) in 4℃4h or 4℃8h was difference with the desialyation in 25℃4h or 25℃8h respectively.2) The desialyation of platelet in 20 ITP patients:The desialyation(RCA%) of effective responses to first-line treatment and invalid for first-line treatment were 0.6(0.3,1.3) and 15.3(8.9,32.8),respectively.And the desialyation(ECL%) were 0.6(0.2,1.7) and 1.8(1.1,6.3),respectively.At the end,we compared the desialyation of the two groups with Wilcoxon.It showed that the difference was statistically significant.3) Specific autoantibodies in 29 ITP:We used the MAIPA method to test specific autoantibodies in ITP.It showed that single anti-GPIbα existed in 3 ITP,single anti-GPⅡbⅢa existed in 14 ITP.At the same time,double positived existed in 4 ITP,double negative existed in 8 ITP.Conclusion The desialyation of platelet can be used as a index in ITP.The dsialyation and specific autoantibodies in ITP can be used to evaluate therapeutic effect in clinical.