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 antihuman 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. J. Clin. Lab. Anal. 11:196–201, 1997. © 1997 Wiley‐Liss, Inc.