[In vivo degradation of immune complexes in the kidney by orally administered enzymes].

Preformed immune complexes were deposited in kidney glomeruli of rabbits after i.v. injection. In vivo disintegration of these complexes by orally administered enzymes was investigated. 3 rabbits were given labelled trypsin and papain and the radioactivity and enzyme activity determined in the blood. The radioactive fraction showed an active enzyme concentration of 3-5 mg%. 13 experimental rabbits and 3 control animals received three i.v. injections of 5 ml preformed soluble immune complexes at 12-hour intervals. 24 hours after the last injection the experimental animals were fed 1600 mg enzyme mixture. All animals were sacrificed 4 hours later and the glomeruli of the kidney were investigated by immunofluorescence. All control animals showed large amounts of immune complexes in the glomeruli. Experimental animals, which had all received oral enzymes showed no immune complexes any more, or only residual immune complexes in some glomeruli. This observation pointed to in vivo disintegration of immune complexes by orally-administered enzymes as providing the basis for the treatment of immune complex diseases.