Department of Allergy, Immunology and Rheumatology, Taichung Veterans General Hospital, Taichung, Taiwan, ROC.
Clin Chim Acta. 2010 Aug 5;411(15-16):1084-9. doi: 10.1016/j.cca.2010.04.004. Epub 2010 Apr 10.
Human parvovirus B19 (B19) infection has been identified as a trigger of antiphospholipid syndrome (APS). However, the precise role of B19-VP1 unique region (VP1u) in patients with antiphospholipid syndrome remains unclear.
IgM and IgG against B19-VP, and serum levels of antibodies directed against cardiolipin (CL), beta2-glycoprotein-I (beta2GPI) and phospholipid (PhL) were determined using ELISA in 45 APS patients. Humoral responses of anti-B19-VP1u were assessed by Western blot and B19 DNA was detected by nested PCR. Absorption experiments were performed using B19-VP1u protein to determine the binding specificity of antiphospholipid antibodies (aPL).
One and 18 of 45 APS patients had detectable levels of anti-B19-VP IgM and anti-B19-VP IgG, indicating recent and past infection respectively. All serum samples from APS patients with diagnostic pattern DNA(-)/IgM(-)/IgG(+) had anti-B19-VP1u activity. APS patients with anti-B19-VP1u antibody had a 4-fold increased risk for recurrent vascular thrombosis compared with those without anti-B19-VP1u antibody. The binding inhibition of CL, beta2GPI, and PhL by absorption with B19-VP1u ranged from 31.4% to 91.1%, 0.8% to 59.8% and 20.2% to 72.1% respectively. Significantly higher inhibition to beta2GPI by B19-VP1u absorption was observed in APS patients with anti-B19-VP1u antibody than in those without anti-B19-VP1u antibody.
We show a close association of B19 infection with aPL production and suggest B19-VP1u may be of pathogenetic importance in some patients with APS.
人类细小病毒 B19（B19）感染已被确定为抗磷脂综合征（APS）的触发因素。然而，B19-VP1 独特区域（VP1u）在抗磷脂综合征患者中的确切作用尚不清楚。
使用 ELISA 法检测 45 例 APS 患者的抗 B19-VP 的 IgM 和 IgG，以及针对心磷脂（CL）、β2-糖蛋白 I（β2GPI）和磷脂（PhL）的抗体的血清水平。通过 Western blot 评估抗 B19-VP1u 的体液反应，并通过巢式 PCR 检测 B19 DNA。使用 B19-VP1u 蛋白进行吸收实验，以确定抗磷脂抗体（aPL）的结合特异性。
45 例 APS 患者中有 1 例和 18 例分别检测到抗 B19-VP IgM 和抗 B19-VP IgG，表明存在近期和既往感染。所有 APS 患者的血清样本（DNA（-）/IgM（-）/IgG（+））均具有抗 B19-VP1u 活性。与无抗 B19-VP1u 抗体的 APS 患者相比，具有抗 B19-VP1u 抗体的 APS 患者发生复发性血管血栓形成的风险增加了 4 倍。B19-VP1u 吸收对 CL、β2GPI 和 PhL 的结合抑制率分别为 31.4%至 91.1%、0.8%至 59.8%和 20.2%至 72.1%。在具有抗 B19-VP1u 抗体的 APS 患者中，B19-VP1u 吸收对β2GPI 的抑制作用明显高于无抗 B19-VP1u 抗体的患者。
我们发现 B19 感染与 aPL 产生密切相关，并表明 B19-VP1u 在某些 APS 患者中可能具有致病性。
