Antibodies cross-reacting with porcine and human trypsin in cystic fibrosis.

A solid-phase radioimmunoassay has been developed for the titration of TbIgG (trypsin binding IgG) in sera of CF patients. Using this assay system it has been found that TbIgG are primarily directed against porcine trypsin and cross-react with human trypsin. A specific subpopulation of anti-human trypsin antibodies has not been found, making unlikely the occurrence of an autoimmune process in CF, at least against human pancreatic enzymes.