Lin Jeong-Shi, Lyou Jau-Yi, Chen Ying-Ju, Chen Pei-Shan, Liu Hsueng-Mei, Ho Chao-Hung, Hao Tsung-Chi, Tzeng Cheng-Hwai
Division of Transfusion Medicine, Department of Medicine, Taipei Veterans General Hospital, National Yang-Ming University College of Medicine, Taipei, Taiwan.
J Formos Med Assoc. 2007 Feb;106(2):105-9. doi: 10.1016/S0929-6646(09)60225-4.
BACKGROUND/PURPOSE: Immune thrombocytopenic purpura (ITP) is an autoimmune disease. Platelet refractoriness is frequently seen in patients with ITP. Platelets express platelet-specific antigens and human leukocyte antigens (HLA). Platelet antibodies to platelet-specific antigens and HLA may be present, but HLA antibodies in patients with ITP have rarely been reported.
Sera from 44 adult patients with ITP were screened for platelet antibodies by two flow cytometric assays. In method I, platelets from normal donor platelets were used as target cells to screen both platelet-specific antibodies and HLA class I antibodies. In method II, the FlowPRA Class I Screening Test kit was used to screen HLA class I antibodies. Fluorescein isothiocyanate (FITC)-conjugated sheep anti-human IgG Fc was used as the staining reagent in both methods. The negative serum control was from one of the normal males with AB blood group who had never received a transfusion. Sera from a pool of five highly sensitized patients were used as the positive control.
Of the 44 sera from patients with ITP, 31 (70.5%) were method I positive, and 28 (63.6%) were method II positive. There was no significant difference between the results of method I and method II (p = 0.439). The distribution of the results of these two tests was: both tests positive in 22 sera, method I positive and method II negative in nine sera, method I negative and method II positive in six sera, and both tests negative in seven sera. The mean platelet counts of patients with positive (41.0 +/- 40.0 x 10(9)/L) and negative (40.4 +/- 26.8 x 10(9)/L) tests by method I did not differ significantly (p = 0.643). The mean platelet counts of patients with (36.7 +/- 31.5 x 10(9)/L) and without (48.1 +/- 43.6 x 10(9)/L) HLA class I antibodies did not differ significantly (p = 0.59).
HLA class I antibodies are frequently found in ITP. The screening of platelet antibodies including platelet-specific antibodies and unappreciated HLA class I antibodies is warranted in patients with ITP.
背景/目的：免疫性血小板减少性紫癜（ITP）是一种自身免疫性疾病。血小板输注无效在ITP患者中很常见。血小板表达血小板特异性抗原和人类白细胞抗原（HLA）。可能存在针对血小板特异性抗原和HLA的血小板抗体，但ITP患者中的HLA抗体鲜有报道。
采用两种流式细胞术检测方法对44例成年ITP患者的血清进行血小板抗体筛查。方法I中，使用正常供体血小板作为靶细胞来筛查血小板特异性抗体和HLA I类抗体。方法II中，使用FlowPRA I类筛查检测试剂盒筛查HLA I类抗体。两种方法均使用异硫氰酸荧光素（FITC）偶联的羊抗人IgG Fc作为染色试剂。阴性血清对照来自从未接受过输血的AB血型正常男性之一。将5例高度致敏患者的混合血清用作阳性对照。
44例ITP患者的血清中，方法I检测阳性者31例（70.5%），方法II检测阳性者28例（63.6%）。方法I和方法II的结果之间无显著差异（p = 0.439）。这两种检测结果的分布情况为：两种检测均阳性22例血清，方法I阳性且方法II阴性9例血清，方法I阴性且方法II阳性6例血清，两种检测均阴性7例血清。方法I检测阳性（41.0±40.0×10⁹/L）和阴性（40.4±26.8×10⁹/L）患者的平均血小板计数无显著差异（p = 0.643）。有（36.7±31.5×10⁹/L）和无（48.1±43.6×10⁹/L）HLA I类抗体患者的平均血小板计数无显著差异（p = 0.59）。
ITP患者中经常发现HLA I类抗体。对ITP患者进行包括血小板特异性抗体和未被重视的HLA I类抗体在内的血小板抗体筛查是有必要的。
