Autoantibodies against platelet membrane glycoproteins in children with acute and chronic immune thrombocytopenic purpura

Abstract

The autoimmune nature of chronic immune thrombocytopenic purpura (ITP) in adults is widely accepted. In contrast, the pathogenetic mechanism in acute and chronic ITP in children is not known. In this report, we studied 39 children with destructive thrombocytopenia, 15 patients with acute ITP and 24 patients with chronic ITP. Platelet autoantibodies to platelet glycoprotein IIb/IIIa were detected in 14 of 24 patients (58.3%) in the chronic ITP group and in four of 15 (26.7%) with acute ITP. Binding ratios (+/- SD) of positive patients were significantly greater (P = .01) in chronic ITP (8.0 +/- 9.1) when compared with those of acute ITP where the binding ratios were only slightly above the normal range (1.9 +/- 0.4). The results show that autoantibodies against platelet glycoproteins are present in the majority of children with chronic ITP confirming the autoimmune nature of this disorder. The minimal elevation seen in the positive children with acute ITP suggests a different pathogenetic mechanism. These data suggest that this approach may be useful in differentiating acute from chronic ITP patients.

Platelet Antibody Detection in Pediatric Immune Thrombocytopenic Purpura: Evaluation of Three Screening Methods

“…Single test sensitivities ranged from 28.1 (EIA) to 39.4% (SPRCA). Our results are consistent with those previously published by other authors [7,8,15,17,18].…”

“…Antibodies against platelet membrane glycoprotein IIb/ IIIa, Ib/IX and Ia/IIa can be detected in many ITP patients [3][4][5][6][7][8][9][10].…”

Controversies in the diagnosis and management of childhood acute immune thrombocytopenic purpura

“…There are conclusive data indicating that the thrombocytopenia in ITP is generated by an IgG autoantibody [8,9]. The initial observations of Harrington et al [10] established that plasma of a patient with ITP could induce thrombocytopenia in healthy volunteer subjects, and subsequent studies showed that the effecting agent inducing thrombocytopenia in patents with ITP is in the gamma globulin fraction and presumably an antibody [11].…”

Platelet‐reactive IgG antibodies cloned by phage display and panning with IVIG from three patients with autoimmune thrombocytopenia

“…At present, no clinical or laboratory parameters are available that could enable the physician to determine the prognosis or the course of the disease in an individual patient (Taub et al, 1995). Although earlier studies (Berchtold et al, 1989b) suggested that platelet gpIIb/IIIa autoantibodies were useful in differentiating between acute and chronic AITP, recent investigations could not detect significant differences in the percentage of those antibodies (Taub et al, 1995).…”