Optimising testing for phospholipid antibodies

Aim-To compare anticardiolipin (ACL) and anti-beta2 glycoprotein 1 (beta 2g p1) enzyme linked immunosorbent assays (ELISAs) in the diagnosis of antipho spholipid syndrome (APS) and to incorporate these results into a meta-analy sis of published data. Method-Three representative commercial ACL ELISAs and an in house beta 2gp1 assay were optimised and then assessed on 124 sera from normal donors, pat ients with infection, or patients with APS. A Medline search was screened f or papers meeting defined criteria to conduct a meta-analysis. The performa nce of the assays used in this study was included. Results-A non-quantitative ACL assay performed at least as well as the anti -beta 2gp1 assay in the diagnosis of APS. Meta-analysis confirmed that neit her assay is perfect, although the anti-beta 2gp1 assay had a higher specif icity and lower sensitivity than the ACL assay. Conclusions-The pooled data suggest that the ACL assay is used to investiga te thrombosis without overt underlying pathology and that the improved spec ificity of the anti-beta 2gp1 assay is exploited where infection, connectiv e tissue disease, or atheroma are present.