Experimental Hemorrhagic Pneumonitis Produced by Heterologous Anti-Lung Antibody

Abstract

Rabbit antibody directed against basement membrane antigens of rat lung capillaries is capable of producing both pulmonary hemorrhages and glomerulonephritis in rats following intravenous injection. The injection of higher doses of antibody causes acute splenitis and focal liver necroses as well. Evidence for the immunologic pathogenesis of these lesions includes the following: a) in vivo localization of radiolabeled antibody can be demonstrated in lung, kidney, liver and spleen; b) fluorescent staining reveals that this antibody is bound in vivo to the vascular basement membranes of the pulmonary capillaries and renal glomeruli, as well as to the splenic reticulum and along the hepatic sinusoids; c) normal rabbit γ globulin and antibody that has been absorbed with lung antigen are both incapable of producing these lesions and neither shows specific organ localization as measured by the paired isotope technique. Antigens derived from or related to vascular basement membrane can be demonstrated in the urine of normal rats, and in the serum of bilaterally nephrectomized rats. Apparently in the turnover of non-renal basement membranes, potentially antigenic fragments reach the circulation and are excreted by the kidneys.