%0 Journal Article
%T Anti-platelet antibody immunoassays in childhood immune thrombocytopenia: a systematic review.
%A Schmidt DE
%A Lakerveld AJ
%A Heitink-Pollé KMJ
%A Bruin MCA
%A Vidarsson G
%A Porcelijn L
%A de Haas M
%J Vox Sang
%V 115
%N 4
%D May 2020
%M 32080872
%F 2.996
%R 10.1111/vox.12894
%X <B>BACKGROUND: </B>In adult immune thrombocytopenia (ITP), an acquired autoimmune bleeding disorder, anti-platelet autoantibody testing may be useful as a rule-in test. Childhood ITP has different disease characteristics, and the diagnostic and prognostic value of anti-platelet antibody testing remains uncertain.<BR><B>OBJECTIVE: </B>To systematically review the diagnostic accuracy of anti-platelet autoantibody testing in childhood ITP.<BR><B>METHODS: </B>PubMed and EMBASE were searched for studies evaluating immunoassays in childhood ITP. Study quality was assessed (QUADAS2), and evidence was synthesized descriptively.<BR><B>RESULTS: </B>In total, 40 studies (1606 patients) were identified. Nine studies reported sufficient data to determine diagnostic accuracy measures. Anti-platelet IgG antibody testing showed a moderate sensitivity (0·36-0·80 platelet-associated IgG [direct test]; 0·19-0·39 circulating IgG [indirect test]). In studies that reported control data, including patients with non-immune thrombocytopenia, specificity was very good (0·80-1·00). Glycoprotein-specific immunoassays showed comparable sensitivity (three studies) and predominantly identified IgG anti-GP IIb/IIIa antibodies, with few IgG anti-GP Ib/IX antibodies. Anti-platelet IgM antibodies were identified in a substantial proportion of children (sensitivity 0·62-0·64 for direct and indirect tests).<BR><B>CONCLUSIONS: </B>The diagnostic evaluation of IgG and IgM anti-platelet antibodies may be useful as a rule-in test for ITP. In children with insufficient platelets for a direct test, indirect tests may be performed instead. A negative test does not rule out the diagnosis of ITP. Future studies should evaluate the value of anti-platelet antibody tests in thrombocytopenic children with suspected ITP.