L. Buo et al., DIFFERENTIAL-DIAGNOSIS OF HUMAN ASCITES - INHIBITORS OF THE CONTACT SYSTEM AND TOTAL PROTEINS, Scandinavian journal of gastroenterology, 28(9), 1993, pp. 777-782
To assess their accuracies as markers for malignancy, we assayed alpha
2-macroglobulin, Cl-inhibitor, alpha1-protease inhibitor, and total pr
oteins in ascites and plasma from patients with gastrointestinal cance
r (n = 15) and non-malignant liver disease (n = 13), using functional
and immunologic assays. For all inhibitors and total proteins determin
ed in ascites, the values in the cancer group were significantly highe
r than the corresponding values in the group with non-malignant liver
disease. The diagnostic accuracy for differentiating malignancy-relate
d from non-malignant ascites was 93% for a alpha1-protease inhibitor v
alue greater-than-or-equal-to 50% of the pool plasma value and 90% for
alpha2-macroglobulin greater-than-or-equal-to 16%, Cl-inhibitor great
er-than-or-equal-to 40% (all functional assays), and total proteins gr
eater-than-or-equal-to 20 g/l (biuret). In conclusion, functional assa
ys for alpha2-macroglobulin, Cl-inhibitor, and alpha1-protease inhibit
or and determination of total proteins in ascites appeared to be very
informative tests for the differential diagnosis of ascites. The test
for alpha1-protease inhibitor gave higher specificity (92% versus 77%)
and likelihood ratio for a positive test (12 versus 4) compared with
the other tests.