Abstract
Abstract
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.
Keywords: ITP, Flow cytometry, MAIPA
Full Text
The Full Text of this article is available as a PDF (787.0 KB).
References
- 1.George J.N., Woolf S.H., Raskob G.E., Wasser J.S., Aledort L.M., Ballem P.J., Blanchette V.S., Bussel J.B., Cines D.B., Kelton J.G., Lichtin A.E., McMillan R., Okerbloom J.A., Regan D.H., Warrier I. Idiopathic thrombocytopenic purpura: a practice guideline developed by explicit methods for the American Society of Hematology. Blood. 1996;88:3–40. [PubMed] [Google Scholar]
- 2.Kuwana M., Kurata Y., Fujimura K., Fujisawa K., Wada H., Nagasawa T., Nomura S., Kojima T., Yagi H., Ikeda Y. Preliminary laboratory based diagnostic criteria for immune thrombocytopenic purpura: evaluation by multi-center prospective study. J Thromb Haemost. 2006;4:1936–1943. doi: 10.1111/j.1538-7836.2006.02091.x. [DOI] [PubMed] [Google Scholar]
- 3.Smith G.A., Ranasinghe E., Ouwehand W.H. The importance of using multiple techniques for detection of platelet antibodies. Vox Sang. 2007;93:306–308. doi: 10.1111/j.1423-0410.2007.00969.x. [DOI] [PubMed] [Google Scholar]
- 4.Rosenfeld G.S., Nichols G., Bodensteiner D.C. Flow cytometric measurement of antiplatelet antibodies. Am J Clin Pathol. 1987;87:518–522. doi: 10.1093/ajcp/87.4.518. [DOI] [PubMed] [Google Scholar]
- 5.Kiefel V., Santoso S., Weisheit M., Mueller-Eckhardt C. Monoclonal antibody-specific immobilization of platelet antigens (MAIPA): a new tool for the identification of platelet-reactive antibodies. Blood. 1987;70:1722–1726. [PubMed] [Google Scholar]
- 6.Cines D.B., McMillan R. Pathogenesis of chronic immune thrombocytopenic purpura. Curr Opin Hematol. 2005;14(5):511–514. doi: 10.1097/MOH.0b013e3282ba5552. [DOI] [PubMed] [Google Scholar]
- 7.Sinha R.K., Kelton J.G. Current controversies concerning the measurement of platelet-associated IgG. Transfus Med Rev. 1990;4:121–135. doi: 10.1016/s0887-7963(90)70257-x. [DOI] [PubMed] [Google Scholar]
- 8.Nielsen H.E., Andersen E.A., Carlsen N., Nir M., Taaning E. Presence of platelet antibodies in idiopathic thrombocytopenic purpura may discriminate acute from chronic disease. Acta Paediatr. 2003;92:1208–1210. doi: 10.1080/08035250310005251. [DOI] [PubMed] [Google Scholar]
- 9.Fabris F., Scandellari R., Ruzzon E., Randi M.L., Luzzatto G., Girolami A. Platelet-associated autoantibodies as detected by a solid-phase modified antigen ELISA test (MACE) are a useful prognostic factor in idiopathic thrombocytopenic purpura. Blood. 2004;103:4562–4564. doi: 10.1182/blood-2003-09-3352. [DOI] [PubMed] [Google Scholar]
- 10.Romero-Guzman L.T., Lopez-Karpovitch X., Paredes R., Barrales-Benitez O., Piedras J. Detection of platelet-associated immunoglobulins by flow cytometry for the diagnosis of immune thrombocytopenia: a prospective study and critical review. Haematologica. 2000;85:627–631. [PubMed] [Google Scholar]
- 11.Zhou J., Liao J., Jiang N.G., Kuang L.H. Platelet autoantibody and its impact on platelet in patients with idiopathic thrombocytopenic purpura. Sichuan Da Xue Xue Bao Yi Xue Ban. 2007;38(6):977–979. [PubMed] [Google Scholar]
- 12.Kaplan C., Porcelijn L., Vanlieferinghen P., Julien E., Bianchi F., Martageix C., Bertrand G., Jallu V. Anti-HPA-9bw (Maxa) feto-maternal alloimmunization, a clinically severe neonatal thrombocytopenia: difficulties in diagnosis and therapy, report on eight families. Transfusion. 2005;45:1799–1803. doi: 10.1111/j.1537-2995.2005.00606.x. [DOI] [PubMed] [Google Scholar]
- 13.Campbell K., Rishi K., Howkins G., Gilby D., Mushens R., Ghevaert C., Metcalfe P., Ouwehand W.H., Lucas G. A modified rapid monoclonal antibody-specific immobilization of platelet antigen assay for the detection of human platelet antigen (HPA) antibodies: a multicentre evaluation. VoxSang. 2007;93(4):289–297. doi: 10.1111/j.1423-0410.2007.00989.x. [DOI] [PubMed] [Google Scholar]
- 14.Berchtold P., Wenger M. Autoantibodies against platelet glycoproteins in autoimmune thrombocytopenic purpura: their clinical significance and response to treatment. Blood. 1993;81:1246–1250. [PubMed] [Google Scholar]
- 15.McMillan R., Wang L., Tani P. Prospective evaluation of the immunobead assay for the diagnosis of adult chronic immune thrombocytopenic purpura. J Thromb Haemost. 2003;1:485–491. doi: 10.1046/j.1538-7836.2003.00091.x. [DOI] [PubMed] [Google Scholar]
- 16.Fujisawa K., Tani P., Piro L., McMillan R. The effect of therapy on platelet-associated autoantibody in chronic immune thrombocytopenic purpura. Blood. 1993;81:2872–2877. [PubMed] [Google Scholar]
- 17.Tomer A. Autoimmune thrombocytopenia: determination of platelet-specific autoantibodies by flow cytometry. Pediatr Blood Cancer. 2006;47:697–700. doi: 10.1002/pbc.20987. [DOI] [PubMed] [Google Scholar]
- 18.Hézard N., Simon G., Macé C., Jallu V., Kaplan C., Nguyen P. Is flow cytometry accurate enough to screen platelet autoantibodies? Transfusion. 2008;48:513–518. doi: 10.1111/j.1537-2995.2007.01556.x. [DOI] [PubMed] [Google Scholar]