Evaluation of three commercial ELISA kits for anticardiolipin and anti-beta2-glycoprotein I antibodies in the laboratory diagnosis of the antiphospholipid syndrome.

摘要

INTRODUCTION: The laboratory criteria of the antiphospholipid syndrome (APS) include lupus anticoagulant (LAC), anticardiolipin antibodies (aCL) and anti-beta2glycoprotein I antibodies (abeta2GPI) IgG or IgM. METHODS: We evaluated three commercial ELISAs for aCL and abeta2GPI IgG and IgM: Asserachrom(R) ('Stago'), Bio-Rad ('BR') and the Bindazyme (the Binding Site, 'BS'). RESULTS: Results of all assays and of LAC were correlated with the clinical background (n=228). Sensitivity for Stago/BS/BR aCL IgG was 14%/15%/18%, for aCL IgM 1%/5%/4%, for abeta2GPI IgG 9%/10%/17% and for abeta2GPI IgM 4%/4%/3%. The specificity for Stago/BS/BR for all assays ranged from 86% to 98%. The positive predictive value (PPV) for Stago/BS/BR aCL IgG was 46%/52%/40%, for aCL IgM 8%/36%/19%, for abeta2GPI IgG 70%/67%/45% and for abeta2GPI IgM 23%/23%/20%. Combining LAC with aCL and abeta2GPI antibodies increased the sensitivity (Stago/BS/BR IgG: 26%/27%/31%, IgM: 22%/21%/26%) and PPV (Stago/BS/BR IgG: 41%/46%/36%, IgM: 34%/40%/36%). Comparing the diagnostic power of the tests, only Stago/BS abeta2GPI IgG had a Chi-square P-value lower than 0.05. The combination of LAC and IgG ELISAs of BS resulted in the lowest P-value (0.098) compared to the other combinations. CONCLUSION: All evaluated ELISAs are a practical tool in the laboratory diagnosis of APS. The diagnostic performance shows slight differences between the ELISAs from the different manufacturers.