Local antibody production in experimental pyelonephritis: amount, avidity, and immunoglobulin class.

LOCAL ANTIBODY FORMATION IN INFECTED RABBIT KIDNEYS WAS STUDIED WITH THREE TECHNIQUES: the ammonium sulfate precipitation technique, the enzyme-linked immunosorbent assay, and by binding of newly synthesized (14)C-labeled antibodies to heat-killed bacteria. Local antibody was detected by day 11 of infection with all three techniques, and a significant correlation was found in titers by all three methods. In these studies, antibody synthesized early was in IgG and IgA class, whereas IgM antibodies appeared later (day 20) in the antibody response. No maturation of avidity of local antibody was noted with time. Since it was necessary to use different animals at each test occasion, individual differences in avidity could account for failure to note an increase in avidity with time.