Jones J V
Department of Medicine, Dalhousie University, Halifax, Canada.
J Rheumatol. 1992 Nov;19(11):1774-7.
Antiphospholipid antibodies (aPL) are found in up to 60% of patients with systemic lupus erythematosus (SLE), and appear to predispose to a number of complications of the disease. We purified IgG from patients with SLE and the antiphospholipid antibody syndrome (APS) who have high levels of aPL and used this IgG in a modified ELISA where we excluded any source of cofactor in the assay. We showed that for 10 of the 11 patients, IgG bound strongly to cardiolipin only in the presence of the cofactor, which was present in fetal calf serum, normal human serum (NHS), and in the infranatant lipoprotein fractions obtained by flotation ultracentrifugation of NHS. We then purified beta 2 glycoprotein I (beta 2GPI) from NHS and showed that for 9 of the 11 samples of IgG, beta 2GPI was as effective, or more effective, than NHS as a source of cofactor. When beta 2GPI was coated on ELISA plate and used as an antigen we found little or no reactivity of patient sera or IgG, suggesting that beta 2GPI alone is not antigenic in our system. Three possible explanations could be put forward to explain the behavior of cardiolipin and beta 2GPI, neither of which is antigenic alone.
抗磷脂抗体（aPL）在高达60%的系统性红斑狼疮（SLE）患者中被发现，并且似乎易导致该疾病的多种并发症。我们从患有SLE且抗磷脂抗体综合征（APS）的aPL水平高的患者中纯化出IgG，并将这种IgG用于改良的酶联免疫吸附测定（ELISA）中，在此测定中我们排除了检测中的任何辅因子来源。我们发现，在11名患者中的10名患者中，仅在辅因子存在的情况下，IgG才会与心磷脂强烈结合，该辅因子存在于胎牛血清、正常人血清（NHS）以及通过NHS的浮选超速离心获得的上清脂蛋白组分中。然后我们从NHS中纯化出β2糖蛋白I（β2GPI），并表明在11个IgG样本中的9个样本中，β2GPI作为辅因子来源与NHS一样有效，或比NHS更有效。当β2GPI包被在ELISA板上并用作抗原时，我们发现患者血清或IgG几乎没有或没有反应性，这表明单独的β2GPI在我们的系统中不是抗原性的。可以提出三种可能的解释来解释心磷脂和β2GPI的行为，它们单独都不是抗原性的。
