1例新生儿血小板减少性紫癜的免疫抗体分析

目的分析1例新生儿血小板减少性紫癜(NAIT)血清中免疫抗体的特异性。方法采用固相凝集法检测患儿及其母亲血清中是否存在抗父亲/抗丈夫血小板抗体,用PAK12试剂盒鉴定血清中的抗体是抗-HLA还是抗-HPA,用ELISA法(PRA)鉴定HLA抗体的特异性,用SSOP法进行父亲、母亲和患儿HLA-Ⅰ类基因分型,用PCR-SSP法进行父亲、母亲和患儿HPA抗原1-5系统基因分型。结果该例NAIT患儿血清中存在来自母体的HLA-Ⅰ类抗体和HPA抗体;HLA-Ⅰ类抗体为抗-Bw6;父亲和患儿的HLA-B位点的宽特异性均为Bw4,Bw6,母亲为Bw4;患儿HPA抗原1-5系统基因型与父亲相同,有3a,母亲没有3a。结论在对NAIT患儿进行实验室诊断时,除注意HPA抗体的作用外,也应重视HLA-Ⅰ类抗体的作用。

Analysis of Immune Antibody in Serum of A Newborn with Neonatal Alloimmune Thrombocytopenia

Objective To analyze the specificity of immune antibody in serum of a newborn with neonatal alloimmune thrombocytopenia (NAIT). Methods The sera of the said newborn and her mother were determined for presence or absence of antibody against the platelet of the newborn's father by solid-phase Coombs test. The anti-HLA and / or anti-HPA in sera were identified by PAK12 kit, and the specificity of anti-HLA by ELISA (PRA). The HLA-Ⅰ genotypes of the newborn and her parents were analyzed by SSOP method, and their HPA 1-5 genotypes by PCR-SSP method. Results Maternal HLA-Ⅰ and HPA antibodies were detected in the serum of newborn. The HLA-Ⅰ antibody of the newborn was identified as anti-Bw6. Both the broad specificities of HLA-B sites of the newborn and her father were Bw4, Bw6, while that of her mother was Bw4. Both the HPA 1-5 genotypes of the newborn and her father were 1a / 1a, 2a / 2a, 3a / 3b, 4a / 4a, 5a / 5a, while that of her mother was 1a / 1a, 2a / 2a, 3b / 3b, 4a / 4a, 5a / 5a. Conclusion Not only anti-HPA, but also HLA-Ⅰ antibodies shall be paid more attention in laboratory diagnosis of NAIT.