Bioplex 2200 multiplex immunoassay system apls igg and igm

The predictive value of the isolated determination of aCL (IgG and IgM) antibodies as screening to identify patients with any consensus-aPL was evaluated in a population of 5245 individuals. This group was made up of all the patients who were referred by their doctors to our laboratory to perform a study of antiphospholipid antibodies over a period of 3 years.
(1-1-2014 TO 12-31-2016). No patients were excluded. In cases where there were more than one sample per patient, only the first determination was evaluated.
Levels of anti B2GP1 and anti cardiolipin of IgG and IgM isotypes were measured using BioPLex 2200 multiplex immunoassay system APLS IgG and IgM (Bio-Rad, Hercules CA, USA). Antibody levels higher than 18-GPL/mL (aCL IgG), 18 MPL/mL (aCL IgM), and 18 U/mL (aB2GP1, IgG/IgM) were considered positive. The cut off values were established following the International Consensus Guidelines on Anticardiolipin and Anti-B2-Glycoprotein I testing with the 99th percentile of the healthy population in our country.
The manufacturer recommendations for cut off values were 20 GPL/mL, 20 MPL/mL and 20 U/mL.

Autoantibodies were measured in pretransplant serum used for crossmatch or in a serum sample obtained up to 15 days before transplantation. All the aPL determinations were performed in center 1.
IgA-aB2GP1 antibodies were quantified in all the centers by enzyme-linked immunosorbent assay (ELISA) using the QUANTA Lite B2 GPI IgA (INOVA Diagnostics Inc., San Diego, CA, USA). A unique assay lot was used for the analysis of the samples from centers 2, 3, 4, and 5.
The anti-cardiolipin (aCL) and aBGPI antibodies of IgG and IgM isotypes in patients from center 1 were measured with QUANTA Lite aCL IgG, QUANTA Lite B2 GPI IgG, QUANTA Lite aCL IgM, and QUANTA Lite B2 GPI IgM (INOVA Diagnostics Inc.). In patients from centers 2, 3, 4 and 5, these were measured using BioPLex 2200 multiplex immunoassay system APLS IgG and IgM (Bio-Rad, Hercules CA, USA).
Antibody levels higher than 18 U/mL were considered positive for aPL of IgG and IgM isotypes and higher than 20 U/mL were considered positive for IgA-aB2GP1. The cutoff values were those recommended by the manufacturer, which coincided with those determined in the healthy population in our country (17 (link), 18 (link)).