Antibody affinity and acute immune complex disease

The affinity of anti-BSA antibody was measured daily in rabbits with acute immune complex disease. Affinity values increased with time (r = 0.87: p less than 0.01). Antibody affinity before antigen elimination was 5.3 +/- 0.7 X 10(5)M-1 (Mean +/- SEM, n = 19); affinity after antigen elimination was 9.6 +/- 1.4 X 10(5)M-1 (n = 7). (p less than 0.01: Student's t-test). At the time serum creatinine was elevated antibody affinity was low averaging 7.6 +/- 1.24 X 10(5)M-1 (n = 9). These findings support the hypothesis that complexes of low affinity antibody and antigen may participate in acute immune complex injury.