Lot-to-Lot Inconsistency of Anticardiolipin Reagents

摘要

The diagnostic criteria for antiphospholipid syndrome include the presence of one or more typical clinical features plus one or more laboratory findings (1). The latter include positivity (on two or more occasions, ≥6 weeks apart) of either lupus anticoagulant or anticardiolipin antibody (ACA).We report inconsistencies among lots of anticardiolipin reagents from one supplier and suggest that the differences are related to changes in calibration materials that are also used by other suppliers of ACA reagents.Several, perhaps most, ACA ELISAs are calibrated with Harris “standards” (Louisville APL Diagnostics, Inc.) or secondary calibrators that are traceable to them. Recently, there has been a change in the latest generation of calibration materials, the LAPL-GM-200 calibrators for IgG and IgM ACA. When the latest LAPL-GM-200 calibrators were produced, the manufacturer attempted to make these new calibrators agree with …