Enzyme immunoassays for specific IgG and IgE antibodies toPichia pastoris components in normal humans

We developed enzyme immunoassays for human anti-Pichia pastoris components (PPC) IgG and anti-PPC IgE antibody titers. Anti-PPC IgG antibody assay were performed using antigen-coated plate and anti-human IgG peroxidase conjugate. The intra- and interassay coefficients of variation (CV) of anti-PPC IgG antibody were 1.83-2.51% and 1.97-2.76%, respectively. The anti-PPC IgE antibody assay was performed using an anti-IgE monoclonal antibody-coated plate, biotin-labeled PPC and avidin-labeled peroxidase, which was not subject to interference by the high titer of anti-PPC IgG antibody. The intra- and interassay CV were 3.83-5.34% and 3.56-5.84%, respectively. We determined and compared anti-PPC IgG antibody titers in the 40 normal individuals. We confirmed that a high titer of anti-PPC IgG antibody is contained in all normal human sera and that these antibodies are directed primarily to mannan by immunoblotting analysis. The ratio of the maximum to minimum anti-PPC IgG antibody titers in normal individuals was > 8,000. Anti-PPC IgG antibody titers did not correlate with the age. However, we did not detect anti-PPC IgE antibody in normal individuals.