Increased levels of aldose reductase in peripheral mononuclear cells from type 2 diabetic patients with microangiopathy

Aldose reductase (AR) protein was measured in peripheral mononuclear cells (PMCs) from 55 patients with type 2 diabetes by a two-site ELISA using anti -human AR monoclonal antibody. AR levels did not correlate with age, durati on of diabetes, and HbA1c. Furthermore, no significant differences were fou nd in AR levels between the patients and healthy subjects. Thirty seven pat ients had at least one of diabetic microangiopathy; retinopathy, neuropathy , or nephropathy. AR levels were significantly higher in the patients with microangiopathy than in those without it (52.3 +/- 15.7 vs. 43.0 +/- 15.2 n g/10(6) cells, P < 0.05). The patients with neuropathy had significantly hi gher AR levels than those without neuropathy (53.7 +/- 15.8 vs. 42.7 +/- 14 .3 ng/10(6) cells, P < 0.05). The same result applied to the patients with retinopathy (54.5 +/- 15.4 vs. 44.6 +/- 15.3 ng/10(6) cells, P < 0.05). The AR levels in the patients with nephropathy tended to give a higher value t han those without it. However, there were no significant differences betwee n the two (53.9 +/- 3.6 vs. 46.4 +/- 2.6 ng/10(6) cells, NS). These results indicate that AR levels in PMCs from type 2 diabetic patients are associat ed with the presence of microangiopathy. The measurement of AR proteins in PMCs with this ELISA system is a useful tool for the clinical study of diab etic complications, and would increase our understanding of the pathogenesi s of the disease. (C) 1999 Elsevier Science Ireland Ltd. All rights reserve d.