Electrical anionic charges on red blood cells are reduced in insulin-dependent diabetic patients

The glomerular polyanion represents a charge-selective filter, restricting the passage of negatively charged plasma proteins, such as albumin. A specific loss of charges on the glomerular capillary wall (GCW) associated with an increased clearance of albumin has been reported in diabetes mellitus as well as many other nephropathies. The authors performed a chemical test based on the binding of the cationic dye Alcian Blue 8GX (AB) in 19 insulin-dependent diabetics, aged 34 +/- 4 years; all were Albustix negative, with normal renal function, normotensive, and in good metabolic control. The authors also studied 19 well-matched healthy controls. Each subject repeated the test on two separate occasions. The mean AB binding value was significantly lower (t-test: p less than 0.01) in diabetics than in controls: 87.5 +/- 2.3 vs. 100.5 +/- 1.6 ng/10(6) red cells. AB binding was not significantly correlated with age, duration of diabetes or metabolic control. A negative correlation was found between the negative charge on red cells and albumin excretion rate in microalbuminuric patients (n = 9). These results suggest a possible role for electrical charges in early stages of diabetic nephropathy.