Quanta lite b2 gpi iga

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)).

IgA anti-B2GPI were quantified using the QUANTA Lite B2 GPI IgA (INOVA Diagnostics Inc., San Diego, CA, USA), due to the low sensitivity of bead-based immunoassays for these antibodies [35 (link)]. Anti-PS/PT of IgG and IgM isotypes were evaluated by enzyme-linked immunosorbent assay (ELISA) using QUANTA Lite anti-PS/PT (INOVA DIAGNOSTICS, San Diego, CA, USA). Cutoffs used to consider the results as positive were: >20 U/mL for IgA anti-B2GPI, >30 U/mL for IgG anti-PS/PT and >40 U/mL for IgM anti-PS/PT. These values correspond to the 99th percentile of a healthy population [18 (link)].
ELISA procedures were performed in a Triturus ^® Analyzer (Diagnostics Grifols, S.A. Barcelona, Spain).