Tumor-associated trypsin inhibitor (TATI) in pleural effusions.

The purpose of this study was to evaluate the usefulness of tumor-associated trypsin inhibitor (TATI) determination in serum and pleural fluid for differential diagnosis of relapsing pleural effusions. The concentrations of TATI were determined in samples of serum and pleural fluid from 51 patients with pleural effusions comprising 20 benign exudates, 5 transudates and 26 malignant effusions. TATI levels overlapped in benign and malignant fluids. This precludes the use of this marker for diagnosis of pleural effusions. For this purpose CEA seems to be the best tumor marker with a sensitivity frequently higher than that of cytology.