Urinary trypsin inhibitory activity for the diagnosis of bacterial infection: a prospective study in 690 patients.
OBJECTIVE
During the acute phase response, interleukin-1 induces production of inter-alpha-trypsin inhibitor. The measurement of urinary trypsin inhibitory activity which results from the effects of inter-alpha-trypsin inhibitor degradation products is easy, quick and inexpensive. We conducted a prospective study to investigate its value as a diagnostic tool in comparison with C-reactive protein.


METHODS
Comparisons were made in 690 consecutive patients at admission to a department of internal medicine.


RESULTS
The level of urinary trypsin inhibitory activity was significantly higher in patients with bacterial infection (mean = 123 IU/g creatinine) than in patients with either viral infection (34 IU), cancer (50 IU), elevated erythrocyte sedimentation rate without infection (45 IU), miscellaneous non-inflammatory diseases (27 IU) or in non-organic controls (19 IU) (Dunnet's test, p << 0.01). The receiver operating characteristic curve showed that sensitivity and specificity of urinary trypsin inhibitory activity were higher than those of C-Reactive protein for the diagnosis of bacterial infection. For levels > or = 60 IU, sensitivity was 75% and specificity 89%. Urinary trypsin inhibitory activity levels fell within 2 days in patients treated for acute bacterial infection.


CONCLUSIONS
Urinary trypsin inhibitory activity could be a useful marker of bacterial infection particularly in patients with fever of unknown origin and/or elevated erythrocyte sedimentation rate.
Piette
A M
AM
Service de Médecine Interne, Centre médico-chirurgical Foch, Suresnes, France.
Saba
J
J
Bernard
N
N
Pougheon
M
M
Abat
O
O
Fermanian
J
J
Piette
J C
JC
Chapman
A
A
D000510:Alpha-Globulins / Q000652:urine*; D001424:Bacterial Infections / Q000175:diagnosis*; D015415:Biomarkers / Q000652:urine*; D002097:C-Reactive Protein / Q000652:urine; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014361:Trypsin Inhibitors / Q000652:urine*
D000510:Alpha-Globulins; D015415:Biomarkers; D014361:Trypsin Inhibitors; C011877:inter-alpha-inhibitor; D002097:C-Reactive Protein