Tumor-associated trypsin inhibitor (TATI) in bone diseases.

The casual observation of high serum levels in (TATI) of tumor associated trypsin inhibitor in patients with osteosarcoma inspired us to evaluate the use of this peptide in the diagnosis of various bone diseases. We determined the serum concentrations of TATI in 35 patients with various bone diseases, i.e. degenerative diseases, bone metastasis and osteosarcomas. The cut off, determined as the 99th percentile of TATI serum levels in healthy volunteers was 32 micrograms/l. TATI has a better sensitivity in osteosarcomas (83%) than in metastatic bone diseases (33%). Its specificity in non-malignant bone diseases was not exceptional (82%). This is probably because TATI may also behave as on acute phase protein, the levels of which can rise in non-malignant diseases and also as a result of a tissue reaction in primary bone tumors.