Establishment of an enzyme-linked immuno-sorbent assay for urinary trypsin inhibitor by using a monoclonal antibody.

Monoclonal antibodies against inter-alpha-trypsin-inhibitor (ITI) were produced. One clone showing specificity for urinary trypsin inhibitor (UTI), a proteolytic fragment of ITI, which is excreted into urine, was selected for the establishment of an enzyme-linked immuno-sorbent assay (ELISA). The ELISA for the quantification of UTI was shown to work reproducibly in the range between 0.5 and 10 ng UTI/ml urine. Urines of several patients suffering from different lung diseases were screened for UTI using the established ELISA. Highest UTI levels were found in the urine of patients with lung empyema. A more moderate increase was observed in patients suffering from lung tuberculosis and from secondary and primary lung tumors.