Delay in growth and the development of nephritis in rats treated with interferon preparations in the neonatal period.

Suckling rats were injected for 14 to 17 days with potent rat-cell-culture interferon preparations or various heterologous interferon or control preparations. Only treatment with rat interferon resulted in a delay in growth and maturation of different organs and the subsequent development of an "immune complex" type nephritis. Thus, 38 of 43 rats treated with rat interferon developed a severe glomerulonephritis. Thus, 38 of 43 rats treated with rat interferon developed a severe glomerulonephritis, whereas only 3 of 99 rats in the various control groups had minimal renal lesions. Deposits of IgG and C3 along the glomerular basement membrane were only seen in interferon-treated rats.