Importance of secretory IgA in human body fluids. I. Development of an enzyme immunoassay for secretory IgA

: This paper describes an enzyme-immunoassay for the quantitative estimation of secretory IgA(S-IgA). As solid phase a monoclonal antibody against human secretory component was used, a polyclonal peroxidase labeled anti-IgA serum as conjugate. Thus, the method was specific for S-IgA. The test was done in microtiter plates, the upper limit was 0.5 ng S-IgA/ml. The standards of our test system ran in normal ranges, the coefficients of variation were 6.9% in the within-day-test and 12.2% in the day-to-day-test. The described test system is effective and sensitive. It is suitable for clinical use.