SERUM BETA-2-MICROGLOBULIN IN CHRONIC DISEASES OF THE PANCREAS

Elevated serum concentrations of beta 2-Microglobulin (beta 2-MG) has been reported in a variety of chronic diseases and solid tumors. We de termined serum beta 2-MG concentrations in 140 subjects divided into f ive groups: group 1, 34 patients with proven chronic pancreatitis, 8 o f whom were studied during a painful relapse; group 2, 40 patients wit h pancreatic cancer staged according to the Cubilla-Fitzgerald classif ication; group 3, 40 healthy subjects; group 4, 10 patients with diges tive nonpancreatic carcinomas; group 5, 16 patients with benign digest ive nonpancreatic diseases. Serum soluble interleukin-2 receptor (sIL- 2R) was also determined in all patients with pancreatic diseases as an index of immune system activation. In addition, serum CA 19-9 was ass ayed in patients of groups 2 and 4, and C-reactive protein (CRP) of gr oups 1 and 5. Renal function, evaluated by serum creatinine determinat ion, was normal in all subjects studied. Patients with pancreatic canc er and those with chronic pancreatitis had serum concentrations of bet a 2-MG significantly higher than those of healthy subjects (p < 0.001 and p < 0.005, respectively). Patients with stage I and stage III panc reatic cancer had similar serum levels of beta 2-MG, and these concent rations were significantly lower than those of patients with stage II tumors (p < 0.002 and p < 0.05, respectively). In chronic pancreatitis patients, those studied during painful relapse of the disease had ser um concentrations of beta 2-MG similar to those studied during clinica l remission. A good correlation was found between serum concentrations of these two proteins (r = 0.73, p < 0.001). In patients with pancrea tic cancer, serum beta 2-MG and serum CA 19-9 were abnormally high in 85 and 75%, respectively; in those with digestive nonpancreatic carcin omas, beta 2-MG was abnormally high in all patients, whereas CA 19-9 w as so in 70%. Elevated serum levels of beta 2-MG in patients with panc reatic cancer may be the result of increased tumor cell turnover or to activation of the immune response by malignancy; the concomitant seru m elevation of beta 2-MG and sIL-2R in these patients supports the lat ter hypothesis. The simultaneous increase in serum levels of sIL-2R, b eta 2-MG, and CRP in patients with chronic pancreatitis probably refle cts a persistent activation of the immune response during clinical rem ission of the disease as well.