A Correlational Research Among Platelet Antibody, Grade And Effect Of Treatment In Children With Itp

Background:Idiopathic thrombocytopenic purpura (ITP), also known as autoimmune thrombocytopenic purpura(ATP), is a common autoimmune bleeding disease in childhood period. Platelet antibody and monocyte-macrophage cell system are the cause of sharp decline of platelets in children with acute ITP. The characteristics of the disease are spontaneous bleeding, thrombocytopenia, prolonged bleeding and poor clot contraction. The first time in 1975, Dixon detected platelet surface immunoglobulin (PAIgG) by useing quantitative methods, and then Woods proved that the target antigens of platelet were membrane glycoprotein(GPⅠb, GPⅡb/Ⅲa) in 1984. After that, platelet antibody detection methods and techniques have been gradually improved. Up to now, two types of platelet antibodies, namely platelet-associated antibody(PAIgA,PAIgG,PAIgM,PAC3) and platelet-specific antibody(anti-GPⅡb/Ⅲa,anti-GPⅠb/Ⅸ,anti-GPⅠa/Ⅱa,anti-GPIV,anti-GPV) have been discovered. At present, Platelet antibodies have been examined on children with ITP in some hospital. With the sensitivity and specificity of antibody detection significantly improved, platelet antibody detection provides some help for diagnosis and therapy in children ITP.Purpose:To investigate the relationship among platelet antibody,grade and treatment effect in children with ITP, in order to provide the theoretical basis by finding affecting prognostic factors in children with ITPMethods:1. Clinical data of 40 children with newly diagnosed acute ITP from April 2008 to January 2010 in Qilu Hospital of Shandong University were analyzed. There were 27 boys and 13 girls and their age was from 3 months to 13 years old. All of them met the diagnostic criteria of ITP children and they were classified in accordance with the classification standards published by Intercontinental Children ITP Study Group(ICIS) in 2006, of which,11 cases in grade one,16 cases in grade two,13 cases in grade three. The standards of treatment and evaluation were in accordance with the'Recommendations of Idiopathic Thrombocytopenic Purpura Treatment (revised draft)', which was published by Hematology Branch of Pediatrics Group of Chinese Medical Association in 1999. The evaluation group was classified as markedly effective group, progress group and ineffective group due to the fact that the following up time was less than 2 yeas. What is more, none of the children was treated by platelet transfusion therapy before be admitted to hospital.2.5ml morning fasting venous blood was taken from every children, and then they were put into EDTE tube and stored in-70℃refrigerator. The PAIgG,PAIgA,PAIgM were tested by enzyme linked immunosorbent assay (ELISA); the GPⅡb/Ⅲa and GPⅠb/Ⅸwere tested by Monoclonal platelet antigen capture assays (MAIPA).3. In order to discuss the value of the antibody detection of platelet in ITP, SAS8.2 was utilized to compare the relationship between the positive rate of the antibody, the grade of the disease and the effectiveness of the treatment.Result:1. In this research, there were 25 boys and 15 girls, age of 5.4±3.46 years old, platelet count 38.48±24.98 X 109/L in admission,7.48±2.59 days in hospital.14 patients were Bone marrow puncture was carried out in 14 patients. Megakaryocyte counts ranged from 18 to 521 and mature barrier was found on megakaryocyte in 14 patients of ITP2. The positive rate of platelet-associated antibody(PAIgA,PAIgG,PAIgM) was 32.5%,80%,45% and platelet-specific antibody (anti-GPⅡb/Ⅲa,anti-GPⅠb/Ⅸ) was 35%,40%.3.The disease grade were:11 cases in grade one (7 boys and 4 girls), 16 cases in grade two (10 boys and 6 girls),13 cases in grade three (8 boys and 5 girls). The sex in these grades had no significant difference (P>0.05).4. Rank correlation and hypothesis testing were used to analyze the relation between positive rate of platelet-associated antibodies (PAIgA, PAIgG, PAIgM) and platelet-specific antibodies (anti-GPⅡb/Ⅲa and anti-GPⅠb/Ⅸ) with the grades of children ITP.It showd that there was no significant relationship between the antibody positive rate and disease grades (P>0.05). However from the values, it can be concluded that along with the increasing of the platelet antibodies positive rate, there was a trend of aggravation in the disease grades.5. There were 23 cases (17 boys and 8 girls) in markedly effective group, 11 patients (7 boys and 4 girls) in progress group,6 cases (3 boys and 3 girls) in ineffective group, and there was no significant difference between gender in these three groups(P> 0.05).6. Rank correlation and hypothesis testing were used to analyze the relation between positive rate of platelet-associated antibodies (PAIgA, PAIgG, PAIgM) and platelet-specific antibodies (anti-GPⅡb/Ⅲa and anti-GPⅠb/Ⅸ) with effectiveness of trentmennt of children with ITP. It showd that there was no significant relationship between the antibody positive rate and effectiveness of treatment. However, observed from the values, it can be concluded that along with the increasing of the PAIgA, PAIgG and anti-GPⅠb/Ⅸpositive rate, there was a trend of deterioration in the effectiveness of treatment.Conclusion:1. Platelet-associated antibody and platelet-specific antibody have certain value for disease grades, along with the increasing of the platelet antibodies, there was a trend of aggravation in the disease grades.2. Some patelet-associated antibody and platelet-specific antibody might supply guidance for the disease grade and effectiveness of treatment of ITP in children.