ABNORMAL PROFILE OF SERUM PROTEINASE-INHIBITORS IN CANCER-PATIENTS

  • 1 January 1984
    • journal article
    • research article
    • Vol. 44  (6) , 2718-2723
Abstract
An antitryptic glycoprotein, EDC1 (MW 27,500), which is immunologically related to the normal serum proteinase inhibitor, inter-.alpha.-trypsin inhibitor (IATI), was excreted in large quantities in the urine of metastatic cancer patients. Immunoreactive titers of urinary EDC1 and 5 serum proteinase inhibitors (including IATI) were measured in 16 patients with hematological cancers, 9 patients with various solid tumors, and 32 healthy subjects. The mean urinary EDC1 levels were 22-fold greater in all cancer patients as compared to normals [187.0 .+-. 136.6 (SD) vs. 8.4 .+-. 8.2 mg/g creatinine; P < 0.001]. In the cancer group, serum levels of immunoreactive .alpha.1-proteinase inhibitor (also called .alpha.1-antitrypsin), .alpha.1-antichymotrypsin, and C1 [complement component C1] inactivator averaged 152, 237 and 165% of the normal values, respectively (P < 0.01). Immunoreactive .alpha.2-macroglobulin levels were unchanged, and immunoreactive IATI levels were depressed (75% of the normals; P < 0.01). The lower levels of IATI and elevated levels of EDC1 are consistent with the latter being derived from the former. In spite of the increased immunoreactive .alpha.1-proteinase inhibitor level, the serum antitryptic capacity of the cancer group averaged only 50% of the normal group (P < 0.01; range, 5-110% of normal average). About 70% of the serum .alpha.1-proteinase inhibitor in the cancer group apparently is functionally inert.