Cabiedes J, Cabral A R, Alarcón-Segovia D
Department of Immunology and Rheumatology, Instituto Nacional de la Nutrición Salvador Zubirán, Mexico City, Mexico.
J Rheumatol. 1995 Oct;22(10):1899-906.
To investigate antibodies to phospholipid-free beta 2-glycoprotein-I (a beta 2 GP-I) in the serum of patients with systemic lupus erythematosus (SLE).
We studied alpha beta 2 GP-I by Western blot, dot blot, and ELISA in 94 patients with SLE. Twenty-one had antiphospholipid syndrome (APS) by clinical and serological criteria, 33 had neither of these features, 18 had the clinical criteria for APS but no serum antiphospholipid antibodies (aPL). and 22 had positive aPL but no related clinical manifestations. As controls, we also studied 76 normal sera. Sera were also inhibited with cardiolipin micelles and tested for anticardiolipin antibodies (aCL) or a beta GP-I activities.
Thirty-five of 39 patients with SLE with clinical manifestations of APS has serum a beta 2 GP-I, while only 2 of 55 patients with SLE without such clinical manifestations had them (p = 0.000000001). Sixteen patients with SLE with clinical APS but aPL negative were a beta GP-I positive. All 35 patients with SLE who were a beta 2 GP-I positive had vascular manifestations, but these antibodies were present in only 4 of 55 patients with SLE without vascular manifestations (p = 0.00000001). No patient having either aPL or a beta 2 GP-I had clinical manifestations of APS, whereas all 19 patients positive for both antibodies had clinical APS. The a beta 2 GP-I positive, aPL negative patients with SLE had clinical APS more frequently (16/18) than did a beta GP-I negative, aPL positive patients with SLE (2/24) (p = 0.000000001). The association of clinical manifestations of APS with a beta 2 GP-I was stronger than with aPL. Inhibition studies also indicate that aPL and a beta 2 GP-I are 2 different antigen/antibody systems.
Our findings indicate that the so called APS associates strongly with antibodies recognizing phospholipid-free beta 2 GP-I. There are patients' sera that also recognize cardiolipin and/or its cofactor beta 2 GP-I, the latter perhaps by reacting with a neoepitope on this protein that appears after its interaction with cardiolipin. These would be the previously considered (beta 2 GP-I dependent) aCL.
研究系统性红斑狼疮（SLE）患者血清中针对无磷脂β2糖蛋白-I（β2GP-I）的抗体。
我们采用蛋白质印迹法、斑点印迹法和酶联免疫吸附测定法对94例SLE患者的αβ2GP-I进行了研究。根据临床和血清学标准，21例患有抗磷脂综合征（APS），33例既无这些特征，18例有APS的临床标准但血清中无抗磷脂抗体（aPL），22例aPL阳性但无相关临床表现。作为对照，我们还研究了76份正常血清。血清还用磷脂酰胆碱微团进行抑制，并检测抗心磷脂抗体（aCL）或β2GP-I活性。
39例有APS临床表现的SLE患者中有35例血清中有β2GP-I，而55例无此类临床表现的SLE患者中只有2例有（p = 0.000000001）。16例有临床APS但aPL阴性的SLE患者β2GP-I阳性。35例β2GP-I阳性的SLE患者均有血管表现，但这些抗体仅在55例无血管表现的SLE患者中的4例中出现（p = 0.00000001）。没有患者同时有aPL或β2GP-I而有APS的临床表现，而19例两种抗体均阳性的患者均有临床APS。β2GP-I阳性、aPL阴性的SLE患者比β2GP-I阴性、aPL阳性的SLE患者更频繁地出现临床APS（16/18比2/24）（p = 0.000000001）。APS的临床表现与β2GP-I的关联比与aPL的关联更强。抑制研究还表明，aPL和β2GP-I是两个不同的抗原/抗体系统。
我们的研究结果表明，所谓的APS与识别无磷脂β2GP-I的抗体密切相关。有些患者血清还能识别心磷脂和/或其辅因子β2GP-I，后者可能是通过与该蛋白与心磷脂相互作用后出现的新表位发生反应。这些就是之前认为的（β2GP-I依赖性）aCL。
