Hematuria and acanthocyturia in patients with diabetes

It has been suggested that the finding of acanthocyturia in patients with hematuria points to the presence of glomerulonephritis. However, little attention has been paid to the finding of acanthocyturia in diabetic patients with hematuria. Here we studied 93 consecutive diabetic patients and explored the prevalence of microscopic hematuria and acanthocyturia in association with normoalbuminuria (NO; urinary albumin excretion (UAE) of < 30 mg/g x creatinine), microalbuminuria (MI; UAE of 30-299mg/g x creatinine), macroalbuminuriaMA; UAE of > or = 300mg/g x creatinine), or chronic renal failure (CRF; serum creatinine levels of > or = 1.1mg/dl for male and > or = 0.9mg/dl for female). We defined microscopic hematuria as > or = 5 erythrocytes per high-power field and acanthocyturia as > or = 5% acanthocytes (erythrocytes of doughnut-like appearance with vesicle-shaped protrusions) among 100 erythrocytes in the centrifuged urinary sediment. Microscopic hematuria was found in 12 (24%) out of 49 patients with NO, in 9 (43%) out of 21 patients with MI, in 6 (75%) out of 8 patients with MA, and in 7 (47%) out of 15 patients with CRF. Patients with microscopic hematuria showed a significant increase in urinary albumin excretion as compared to those without (836 +/- 265 vs. 135 +/- 56, p < 0.01). Of patients with microscopic hematuria, acanthocyturia was observed only in 2 (22%) out of 9 patients with MI and in 2 (33%) out of 6 patients with MA. Two of 4 patients with acanthocyturia had elevated serum levels of IgA and chronic tonsillitis, which indicated the occurrence of IgA nephropathy in these patients. Thus, microscopic hematuria was common and associated with elevated UAE, while acanthocyturia was rare and observed only in patients with elevated UAE. We propose that more attention should be paid to the finding of acanthocyturia in diabetic patients with hematuria and albuminuria.