Autoantibody profiling of patients with antiphospholipid syndrome using an automated multiplexed immunoassay system

The antiphospholipid syndrome (APS) is an autoimmune disease defined by the co-occurrence of clinical and serological symptoms [presence of at least one of the antiphospholipid autoantibodies (aPL), such as anti-cardiolipin (aCL) IgG/IgM and anti-β2glycoprotein I (aβ2GPI) IgG/IgM]. The measurement of these autoantibodies constitutes the first-line approach for the diagnosis of APS. Recently the advent of multiplex proteomic technologies seems to be an optimal solution for the parallel detection of autoantibodies (IgG, IgA, IgM) related to APS. The BioPlex 2200 is an automated commercial platform based on the multi-analyte profiling technology that allows the detection of different types of autoantibodies, particularly ANA, ENA, dsDNA, PR3, MPO, GBM. We performed firstly a study to evaluate the diagnostic accuracy of this analytical system in a group of APS patients. The BioPlex system showed a good diagnostic accuracy for all test evaluated, very similar to that of the other established commercial singleplex immunoassays. In our study, the simultaneous detection of aCL and aβ2GPI of IgA isotype in addition to IgG and IgM isotypes did not increase the diagnostic sensitivity for APS. The good diagnostic accuracy, the high level of automation, and the high throughput make this multiplex platform a very useful and practical tool for the laboratory diagnosis of aPL in daily practice.