Immune thrombocytopenic purpura is an acquired disorder, in which accelerated platelet consumption is due to platelet
autoantibodies. The aim of this study was to investigate the clinical value of platelet
autoantibodies assay in children with
ITP and to evaluate flow cytometry in the detection of platelet
autoantibodies in comparison with
monoclonal antibody specific immobilization of platelet
antigen (MAIPA) assay. We measured platelet
autoantibodies by flow cytometry and MAIPA in 18 children with
ITP (6 acute, 7 chronic and 5 in remission), in addition to 5 healthy children with matched age and sex as a control group. Significant elevation of platelet-associated
immunoglobulin G (PAIgG), PAIgM and PAIgA was demonstrated in children with acute
ITP compared to controls and children with chronic
ITP (P < 0.05). There was significant elevation of PAIgG and PAIgM in children with acute
ITP compared to children with
ITP in remission (P < 0.05). There was significant negative correlation between platelet count and PAIgG levels in
ITP children (r = -0.717; P = 0.001). Flow cytometry found PAIgG in 94.4% of
ITP children. MAIPA has detected platelet specific
IgG autoantibodies in 83.3% of
ITP children. ROC analysis revealed sensitivity of 94%, specificity of 57% with overall accuracy of 83% for detection of PAIgG by flow cytometry compared to MAIPA.
CONCLUSIONS: Platelet
autoantibodies testing in
ITP can discriminate acute from chronic forms of the disease and is helpful in follow up of patients. Determination of PAIgM in combination of PAIgG could be of interest in the investigation of
ITP. Flow cytometry is a sensitive method of detection of platelet
autoantibodies that could be used in screening of suspected
ITP and should be followed by MAIPA assay in positive cases to establish the diagnosis.