Cellular Hypersensitivity to Human Pancreatic B-cell Clone in Diabetes Mellitus and its Relationship to the Presence of Islet Cell Antibodies

Abstract

A leukocyte migration inhibition test on the human pancreatic B-cell clone (JHPI-1) was performed in 13 IDDM patients with islet cell cytoplasmic antibody (ICCA) and/or islet cell surface antibody (ICSA), 15 IDDM patients without ICCA or ICSA, 34 NIDDM patients and 17healthy controls. The mean values for the migration index (M.I.%) in each group were 85.4±6.9, 89.1±10.9, 98.3±7.9 and 100.0±8.5. The M.I. values were significantly decreased in IDDM patients than in NIDDM patients and controls irrespective of whether or not there were islet cell antibodies in the patients' sera. When M.I. values less than 0.83 (Mean-2 S.D.) were taken as indicative of inhibition, the percentage of IDDM and NIDDM patients with migration inhibition were 32% and 0% respectively. And the decreased M.I. values in IDDM patients proved not to be due to non-specific migration inhibition by normal M. I. values, with the human fetal lung fibroblast cells (W138) as antigen. Our data suggested that the lymphocytes of IDDM patients might be sensitized by pancreatic B-cell antigen (s) present in the JHPI-1 cells, which promoted leukocyte migration inhibition. No correlation between the migration indices and duration of diabetes mellitus in IDDM patients was observed (r=0.254, Y=84.9+0.49X). LMT to JHPI-1 seems to be useful in detecting the abnormal cell-mediated immunity even in patients with longstanding IDDM.