Schmidt David E, Heitink-Polle Katja M J, Porcelijn Leendert, van der Schoot C Ellen, Vidarsson Gestur, Bruin Marrie C A, de Haas Masja
Department of Experimental Immunohematology, Sanquin Research, Amsterdam, the Netherlands.
Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands.
J Thromb Haemost. 2020 May;18(5):1210-1220. doi: 10.1111/jth.14762. Epub 2020 Apr 12.
Anti-platelet antibody testing may be useful for the diagnosis and management of childhood immune thrombocytopenia (ITP).
Here we aimed to assess the prevalence and prognostic significance of anti-platelet glycoprotein-specific IgM and IgG antibodies.
Children with newly diagnosed ITP were included at diagnosis and randomized to an intravenous immunoglobulins (IVIg) or careful observation group (TIKI trial). In this well-defined and longitudinally followed cohort (N = 179), anti-platelet glycoprotein-specific IgM and IgG antibodies were determined by monoclonal antibody-immobilization of platelet antigens.
The dominant circulating anti-platelet antibody class in childhood ITP was IgM (62% of patients); but IgG antibodies were also found (10%). Children without IgM platelet antibodies were older and more often female. There was weak evidence for an association between IgM anti-GP IIb/IIIa antibodies and an increased bleeding severity (P = .03). The IgM and IgG anti-platelet responses partially overlapped, and reactivity was frequently directed against multiple glycoproteins. During 1-year follow-up, children with IgM antibodies in the observation group displayed a faster platelet recovery compared to children without, also after adjustment for age and preceding infections (P = 7.1 × 10 ). The small group of patients with detectable IgG anti-platelet antibodies exhibited an almost complete response to IVIg treatment (N = 12; P = .02), suggesting that IVIg was particularly efficacious in these children.
Testing for circulating anti-platelet antibodies may be helpful for the clinical prognostication and the guidance of treatment decisions in newly diagnosed childhood ITP. Our data suggest that the development of even more sensitive tests may further improve the clinical value of antibody testing.
抗血小板抗体检测可能有助于儿童免疫性血小板减少症（ITP）的诊断和管理。
我们旨在评估抗血小板糖蛋白特异性IgM和IgG抗体的患病率及其预后意义。
新诊断为ITP的儿童在诊断时纳入研究，并随机分为静脉注射免疫球蛋白（IVIg）组或密切观察组（TIKI试验）。在这个定义明确且进行纵向随访的队列（N = 179）中，通过血小板抗原的单克隆抗体固定法测定抗血小板糖蛋白特异性IgM和IgG抗体。
儿童ITP中主要的循环抗血小板抗体类型为IgM（62%的患者）；但也发现了IgG抗体（10%）。无IgM血小板抗体的儿童年龄较大，女性更为常见。有微弱证据表明IgM抗GP IIb/IIIa抗体与出血严重程度增加有关（P = 0.03）。IgM和IgG抗血小板反应部分重叠，且反应性常针对多种糖蛋白。在1年的随访中，观察组中有IgM抗体的儿童与无IgM抗体的儿童相比，血小板恢复更快，在调整年龄和既往感染因素后也是如此（P = 7.1×10）。一小部分可检测到IgG抗血小板抗体的患者对IVIg治疗表现出几乎完全的反应（N = 12；P = 0.02），这表明IVIg对这些儿童特别有效。
检测循环抗血小板抗体可能有助于新诊断的儿童ITP的临床预后评估和治疗决策指导。我们的数据表明，开发更敏感的检测方法可能会进一步提高抗体检测的临床价值。
