Type 2 Diabetes, Chronic Kidney Disease Clinical Trial
Official title:
Retrospective Study of Renal Biopsies Indications and Their Results in Patients With Type-2 Diabetes : a Multicenter Study
The WHO (World Health Organisation) estimated the prevalence of diabetes to be 422 million
people in 2014, compared to 108 million in 1980. This has led to an increasing number of
diabetic patients referred to nephrologists for diagnostic purposes. Diabetic nephropathy is
the most common renal disease in this population and is usually a presumptive diagnosis based
on clinical and biological features although microscopic examination of a renal sample
acquired through renal biopsy is the only way to be certain of this diagnosis. However,
kidney biopsy is an invasive procedure carrying a low but incontestable risk of adverse event
such as post-procedural pain and bleeding. Consequently, nephrologist around the world feel
that renal biopsy should only be performed in patients with type 2 diabetes to detect
non-diabetic renal disease, when the diagnosis of diabetic nephropathy is dubious or
unlikely. This likeliness is based on the presence or absence of typical feature such as
diabetic retinopathy, hematuria, progressive decline of renal function or increase of
proteinuria, long duration of diabetes, nephrotic syndrome. These feature were identified by
the comparison of patients with type 2 diabetes and non-diabetic renal disease (alone or
associated to diabetic nephropathy) and isolated diabetic nephropathy.
However, it is not known if the presence (or absence) of these atypical features by
themselves are indeed signs of non-diabetic renal disease and necessitate to perform renal
biopsy. The aim of the study is to determine if these atypical features are relevant
indications to perform renal biopsy. To answer this question, will be analyze the medical
records of patients with type 2 diabetes who underwent renal biopsy in five French nephrology
center to determine, in each case, the indication of the biopsy and if this latter benefitted
the patients.
In addition, will be evaluate the prognosis value of the Renal Pathology Society
classification of diabetic nephropathy in patients with type 2 diabetes and diabetic
nephropathy.
The purpose of the study is to evaluate the accuracy of kidney biopsies indications in
patients with type 2 diabetes to diagnose non-diabetic renal disease based on canonical
atypical features (Absence of diabetic retinopathy, Low or rapidly decreasing GFR, Rapidly
increasing proteinuria or nephrotic syndrome and Presence of active urinary sediment. This
study is a retrospective observational case only study, recruiting patients over 18 years old
with type 2 diabetes who underwent kidney biopsy in five French nephrology centers between
2006 and 2015.
Will be collected demographical, clinical and biological data at the time of the renal biopsy
and at the last follow-up from the patients' medical charts.
Indications for renal biopsy will be categorized as
1. Atypical feature of etiological significance in the presence of any atypical feature not
listed below (including acute kidney injury as defined by the stage 1 of KDIG
guidelines)
2. Brutal nephrotic syndrome in the absence of the above criterion
3. Rapid decline of GFR (defined as 50 % eGFR decline over >1 week but < 1 year) in the
absence of criteria 1-2
4. Absence of proteinuria in the absence of criteria 1-3
5. Rapid increase of proteinuria in the absence of criteria 1-4
6. Presence of hematuria in the absence of criteria 1-5
7. Absence of diabetic retinopathy in the absence of criteria 1-6 Will be evaluate the
actual probability to reach a non-diabetic renal disease for each of these indications.
Will be also perform a classical analysis by assessing the association of clinical and
biological feature such as HbA1c, diabetes duration, absence of diabetic retinopathy,… with
the presence of a non-diabetic renal disease.
In addition, the biopsy samples will be scored according to the RPS diabetic nephropathy
classification to evaluate the prognostic value of this classification.
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