Evaluation of the microleukocyte adherence inhibition assay as an immunodiagnostic test for pancreatic cancer.

Abstract

Abstract Carcinoma of the pancreas is the fifth most lethal cancer in humans. Its almost uniform mortality rate is largely related to the rarity with which a diagnosis is established early in the course of the disease. In this study we have evaluated the leukocyte adherence inhibition (LAI) assay as a specific immunodiagnostic test for the presence of pancreatic cancer. Ninety-seven micro-LAI assays were performed on 80 individuals. Buffy-coat leukocytes from 22 preoperative pancreatic carcinoma patients; 17 benign disease patients, primarily with acute pancreatitis; 16 patients with upper gastrointestinal cancers other than pancreatic carcinoma; and 25 normal healthy volunteers were tested against crude membrane extracts of pancreas and colon carcinoma. An LAI index of −0.2 (an approximately 20% reduction in leukocyte adherence) distinguished between patient populations. Of the 22 pancreatic carcinoma patients, buffy-coat leukocytes from 20 had a mean adherence index of less than −0.2. When the membrane preparation was derived from colon carcinoma, the mean adherence index was 0.13. In contrast, only 2 of 58 individuals who served as controls gave a positive LAI value in the presence of the pancreatic carcinoma extract. Duplicate testing of 13 different individuals indicated that the test was highly reproducible. The use of coded specimens as well as a “double-blind” procedure effectively ruled out experimenter bias. Thus, the micro-LAI assay is able to detect specifically pancreatic cancer and discriminate between pancreatic carcinoma and acute pancreatitis, other forms of cancer, and the normal state. These results suggest an immunodiagnostic potential for the micro-LAI assay in pancreatic cancer.