Rapid quantitation of immunoglobulin G antibodies specific for blood group antigens A and B by surface plasmon resonance

Abstract

The measurement of immunoglobulin (Ig) G blood group A/B antibody(anti-A/B) levels is important for ABO-unmatched organ recipients because the effective removal of the antibodies improves their prognosis. Currently existing methods to detect IgG anti-A/B suffer limitations owing to high costs, low throughput, and poor adaptability to automation. We have developed a rapid means to quantitate IgG anti-A/B by surface plasmon resonance (SPR). To investigate the accuracy, a serially diluted plasma sample from a donor was measured with the SPR method. Moreover, IgG anti-A/B titers in 45 healthy volunteers were measured both by the SPR and by the standard tube test (TT) method, as were plasma samples from two ABO-unmatched organ recipients. The change in titers when the same plasma was diluted was precisely reflected by the SPR method. The coefficients of correlation between SPR and TT methods for IgG anti-A and anti-B were 0.85 and 0.56, respectively. The SPR values also paralleled the TT values, which showed a decline in titers after the removal of antibodies by double-filtration plasmapheresis or plasma exchange. This SPR method can be used to measure IgG anti-A/B titers in the plasma very quickly and quantitatively.