Alport syndrome is a rare, inherited condition characterized by a combination of glomerular nephropathy progressing to kidney failure, deafness, and eye involvement. This disease is associated with mutations in the genes encoding one of the three IV collagen chains expressed in the glomerular basement membrane. Significant progress has been made in understanding the molecular mechanisms responsible for the disease, but relatively little in understanding the progression of renal failure and in the area of therapeutics. We have shown in a retrospective European study that blockers of the renin angiotensin system may slow disease progression, but no controlled studies have been performed. Finally, innovative therapies (anti-micro-RNA, stem cells) have recently shown their effectiveness in animal models of the disease, and industrials are planning to quickly carry out phase 1 trials to test molecules. Carrying out therapeutic trials in humans will require full knowledge of the natural history of the disease (isolated hematuria, microalbuminuria, macroalbuminuria, renal failure and its progression) and gathering a sufficient number of patients, especially in the early stages. These trials and the indications for treatments would be greatly facilitated by the discovery of biomarkers that make it possible to predict the progression to renal failure earlier than the onset of proteinuria.
The study aims to:
* Establish a European database on Alport syndrome to assess the natural history of the disease. * To investigate the impact of the disease on the educational and professional life of patients and their families, and on the adherence and tolerance to renin-angiotensin system blockers prescribed to proteinuric patients. * Investigate access to molecular diagnostics and genetic counseling, as well as identify biomarkers that can predict progression of kidney disease.
This project will be carried out at a French level with the support and participation of the very active renal rare disease sector, in collaboration with various countries wishing to participate.
Diagnosis of AS based on electron microscopic examination of the renal biopsy and/or molecular studies and/or abnormal expression of type IV collagen chains on skin and/or glomerular basement membranes.
Signed informed consent
None
The countries that are potentially interested in joining the project have identified in their local records about 100 (Germany), 200 (Spain), 100 (United Kingdom), 785 (Italy), 100 (Belgium) patients. The database ASTOR in USA have included 800 patients. For France, the CEMARA database contains currently 680 Alport Syndrome patients while there are 950 identified patients in France. These patients are followed in nephrology and paediatric nephrology services belonging to the French network for rare renal diseases. Prevalent cases will include cases already registered in the different existing databases in the different countries, after monitoring that the inclusion criteria are respected. There is no known estimated incident rate, but according to the available information and the estimated prevalence rate (1/5,000), it is expected to enrol roughly between 100 and 200 incident patients/year in the study.
Cohort
Prospective
Not listed
Renal function: eGFR, age at ESRD, requirement of Renal Replacement Therapy (RRT) and type of RRT
Urine bio-analysis results: Presence or not and quantification of hematuria, microalbuminuria and proteinuria
Presence or not of hypertension
Level of Hearing loss
Adverse events for the long-term safety of RAAS blockers treatment
Quality of life questionnaires
Impact of disease on quality of life will be evaluated through scores of quality of life questionnaires SF36 for Adult et SF10 for paediatric patients
Compliance
Compliance will be evaluated using X. Girerd Compliance Questionnaire
Disease stage
Stratification of patients according to their disease stage; patients' distribution analysis among countries
Urinal concentration of specific molecules
Correlation assessment between the urinal concentration of the five molecules recently described by Terzi's lab as predicting progression of CKD (or other putative biomarkers) with the rate of decline of the GFR (according of the estimated GFR) on a 3 year- period
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