The effect of protein deficiency on the development of chronic antigen-antibody complex disease in mice

Mice genetically selected to produce antibodies of either high or low affinity to protein antigens injected in saline were fed either a normal protein diet or a protein-deficient diet and were given daily injections of HSA for up to 73 days to induce chronic antigen-antibody complex disease. In low-affinity mice fed the normal protein diet, this resulted in impairment of renal function, deposition of immunoglobulin, C3 and HSA in the glomeruli, high levels of circulating antigen-antibody complexes and death from apparent renal failure in 50% of the animals. High-affinity mice on either diet had no impairment of renal function, fewer deposits in the glomeruli, lower levels of circulating complexes and no deaths. Low-affinity mice fed the protein-deficient diet had less impairment of renal function and less glomerular deposition of complexes than did low-affinity mice fed the normal diet. In addition, none of these mice died from renal failure. These results demonstrate that the protein-deficient diet reduced the severity of the experimental chronic antigen-antibody complex disease in low affinity mice but did not increase the susceptibility of high-affinity mice to the disease.