Chronic immune complex disease in mice: the role of antibody affinity

Two lines of mice selectively bred for producing high and low affinity antibody to protein antigens were repeatedly injected with human serum albumin and the severity and pattern of immune complex disease induced in this way was studied in the two lines. In low affinity mice, there was a greater intensity of deposits in the glomeruli shown by immunofluorescence, and more antibody was eluted from kidney homogenates compared to high affinity line mice. In the low affinity mice, complexes were mainly on the basement membrane whereas in high affinity mice, the localization of immune complexes was predominantly mesangial. However, no significant difference in glomerular filtration rates between the two lines was obtained. The immunopathological significance of antibody affinity is discussed in the light of these results.