[Clinical value of the determination of urinary antitrypsin activity]

Urinary trypsin inhibitory capacity is mainly due to the excretion of a glycoprotein which is immunologically related to the inter alpha-trypsin inhibitor and may be a proteolytic degradation product of that substance. It was tested in 133 subjects divided into 7 groups: 24 healthy controls (group A), 21 patients with bacterial infection (group B), 37 with bacterial infection under antibiotic therapy (group C), 25 with connective tissue disease (group D), 8 with infected connective tissue disease (group E), 14 with cancer (group F) and 4 with infected cancer (group G). Urinary trypsin inhibitory capacity level was very low in controls (3.32 +/- 0.8 U/g urinary creatinine), but it was dramatically increased when infection was present (149.67 +/- 23.6 U/g urinary creatinine). This test appeared to be more effective than serum C-protein measurement simultaneous carried out in the same patients. Urinary trypsin inhibitory capacity is not related to the degree of proteinuria in the urine sample, but it is increased in patients with chronic renal failure excluded from this study. Thus, its measurement is a sensitive, easy and useful test for detecting and monitoring infections. The return to its physiological value is a very good argument in favour of therapeutic effectiveness.