Autori: F. Fiacco (1), A. Cappoli (1), I. Umbro (2), A. Zavatto (1), F. Moccia (1), I. Loconte (1), E. Zanetel (1), G. D’Amati (3) C. Giordano (3), B. Cerbelli (3), S. Golubovic (1), (4), A.P. Mitterhofer (1)
Affiliazioni: (1) Department of Clinical Medicine (2) Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences (3) Department of Radiological, Oncological and Pathological Sciences, 4. Erasmus+ University of Novi Sad, Policlinico Umberto I, Sapienza University of Rome
Introduction: Renal diseases in patients with diabetes mellitus (DM) include diabetic nephropathies (DN), non-diabetic renal diseases (NDN) and mixed forms. The prevalence of DN among DM patients seems to be overestimated because of a prevalent clinical diagnosis. Several groups have studied renal biopsies (RB) from diabetic patients considering presence of following criteria: unexplained haematuria, duration of DM <10 years, absence of diabetic retinopathy and neuropathy, rapidly worsening renal function, sudden onset of nephrotic range proteinuria. In these cases the most frequent NDN diagnoses are IgA nephropathy, membranous nephropathy and focal segmental glomerulosclerosis (FSGS). Generally, RB in DM patients has focused on identifying NDN, even if it is under debate to perform it in all diabetic nephropathic patients.
Materials and methods: We report two cases of 50 years-old patients suffering from type 1 diabetes mellitus (DMT1), hypertension, chronic kidney disease (CKD) with estimated-GFR (MDRD) 50 ml/min and nephrotic proteinuria.
The first patient (P1) is a woman with:
- diagnosis of DMT1>10 years,
- diabetic retinopathy and neuropathy
- anemia
- sustained hematuria ( ≈ 22 RBC/HP),
- frequent episodes of hypoglicemia,
- sudden onset of symptomatic nephrotic proteinuria
- stable renal function
- previous microalbuminuria
- good blood pressure control with 4 antihypertensive agents, including a diuretic
The second patient (P2) is a man, smoker with:
- diagnosis of DMT1<10 years
- absence of diabetic retinopathy and other micro/macrovascular complications
- no hematuria
- mild glycemic control
- sudden onset of asymptomatic nephrotic proteinuria
- stable renal function.
- optimal blood pressure control with RAAS inhibitor
In both patients, no autoantibodies or monoclonal proteins were detected in blood and urine. C3, C4 complement factors were normal and we excluded most common viral infections. Renal ultrasound was normal in both patients. RB showed an idiopathic FSGS in P2, and a DN in P1.
Conclusions: The utility of RB in patients with DM is currently an object of debate. RB is currently considered a determinant factor for characterizing renal disease in DM. In our cases, we perform RB to assess the extent of renal damage for appropriate and timely intervention in order to delay the progression of end stage renal disease. In both cases we expected a DN on RB considering clinical features and the fact that NDRD is rare in patient with DMT1. However, some clinical elements such as hematuria and good glycemic control in P1, absence of retinopathy, duration of DM <10 years in P2 and sudden onset of nephrotic proteinuria in both patients could be related to NDRD. With our cases we want to highlight that the utility of RB in patients with DM is still debated since there is no overall consensus on timing and indications. We believe that performing RB in more DM patients will allow us to define more reliable criteria for RB indication.
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