Selectivity of the micro-leukocyte adherence inhibition assay in pancreatic cancer

A modified leukocyte adherence inhibition assay was performed on white blood cells from patients with ductal pancreatic cancer, other malignancies, benign gastrointestinal diseases including pancreatitis, and healthy controls, using four different ductal pancreatic cancer membrane preparations and similar preparations from gastric and colorectal cancers. A mean adherence index of less than or equal to 0.2 was evidence that the leukocytes "recognized" the antigen(s). In 9 of 10 patients with localized pancreatic cancer, 13 of 15 leukocyte populations "recognized" the pancreatic cancer antigen(s) and not other tested antigen(s). Leukocytes from only 11 of 18 patients (17 of 29 assays) with metastatic pancreatic cancer "recognized" the pancreatic tumor antigen (and no other antigen). The inability to recognize the pancreatic tumor antigen(s) was not related to nutritional, biochemical or therapeutic status of the patient, but was related to the demonstration of a response to skin test antigens. In contrast, 3 of 35 leukocyte populations in 2 of 31 patients with malignancies other than pancreatic, 1 of 28 with benign gastrointestinal disease, and one of 38 healthy control populations "recognized" the antigen. The LAI is worthy of further study in the differential diagnosis of pancreatic cancer.