Dysmorphic erythrocytes are superior to hematuria for indicating non‐diabetic renal disease in type 2 diabetics

Abstract

Aims/IntroductionThere are sparse and limited studies on erythrocyte morphology in renal biopsy identifying nephropathic patients among type 2 diabetics. The present study sought to clarify the predictive value of dysmorphic erythrocytes in type 2 diabetics with non‐diabetic renal disease and influences on hematuria.Materials and MethodsWe examined 198 patients with type 2 diabetes who underwent kidney biopsies between 2012 and 2013. Hematuria was defined as >3 or >10 red blood cells per high‐power field (RBCs/hpf) in urine sediment. If >80% of the erythrocytes were dysmorphic, glomerular hematuria was diagnosed. Clinical findings and predictive value of dysmorphic erythrocytes were compared between patients with hematuria (n = 19) and those without (n = 61). The potential risk factors for hematuria among diabetic nephropathy patients were also screened.ResultsThere was a statistically significant difference between the diabetic nephropathy group and the non‐diabetic renal disease group (6.6 vs 16.8%; P = 0.04) when the demarcation point of hematuria was 10 RBCs/hpf. When the definition of hematuria was based on an examination of urinary erythrocyte morphology, a marked difference was seen (3.3 vs 24.8%; P < 0.001). Glomerular hematuria showed high specificity and a positive predictive value (0.97 and 0.94, respectively) in non‐diabetic renal disease. A multivariate analysis showed that nephrotic syndrome was significantly associated with hematuria (odds ratio 3.636; P = 0.034).ConclusionsDysmorphic erythrocytes were superior to hematuria for indicating non‐diabetic renal disease in type 2 diabetics. Nephrotic syndrome was an independent risk factor for hematuria.

Design and validation of a scoring model for differential diagnosis of diabetic nephropathy and nondiabetic renal diseases in type 2 diabetic patients

“…40 In addition, glomerular hematuria, defined as hematuria comprising >80% dysmorphic erythrocytes or hematuria comprising >5% acanthocytes, may be a better predictor of NDRD. 24 Nonetheless, our study did not support this claim. Although the proportion of glomerular hematuria in the NDRD group was higher than in the DN group (12.9% vs 8.7%), the difference was not statistically significant (P = .487).…”

“…An alternate explanation is that there are areas of aneurysmal dilatation and subsequent rupture in glomerular capillaries, which is similar to the retinal microaneurysms . In addition, glomerular hematuria, defined as hematuria comprising >80% dysmorphic erythrocytes or hematuria comprising >5% acanthocytes, may be a better predictor of NDRD . Nonetheless, our study did not support this claim.…”

“…DR was confirmed or excluded by ophthalmologists with a direct ophthalmoscopy after mydriasis and fundus photography. Glomerular hematuria was defined as red blood cell count >8000/mL with more than 80% of dysmorphic erythrocytes in a urinary sediment sample . The pathologic criteria for diagnosis of DN included glomerular basement membrane thickening, mesangial expansion, and diffuse glomerulosclerosis, with or without K‐W nodules.…”

“…Glomerular hematuria was defined as red blood cell count >8000/mL with more than 80% of dysmorphic erythrocytes in a urinary sediment sample. 24 The pathologic criteria for diagnosis of DN included glomerular basement membrane thickening, mesangial expansion, and diffuse glomerulosclerosis, with or without K-W nodules. Other supportive features were exudative lesions, such as fibrin caps, capsular drops, or hyaline thrombi.…”

Timing of kidney biopsy in type 2 diabetic patients: a stepwise approach

“…The difference in DM duration might come from patients without diabetic retinopathy, and the duration of DM is also a factor predicting the presence of NDRD within this subgroup. The presence of hematuria has been considered as one of the atypical features suggesting the presence of NDRD in the previous guidelines [25] and reports [16,28,30,[32][33][34][35][36][37]. However, there are also some studies suggesting that hematuria is not an uncommon finding in patients with typical DN (between 35 and 78%) and thus is not useful in predicting NDRD [38][39][40][41].…”