SP366CLINICAL PHENOTYPE OF ADPKD PATIENTS AT THE TIME OF REFERRAL TO NEPHROLOGISTS: A MULTICENTER SURVEY IN ITALY

Abstract

Introduction and Aims: Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most common genetic kidney disease and the fourth leading cause of kidney failure in most renal registries worldwide. Referral of ADPKD patients to nephrologists is considered of potential importance to retard the evolution of the disease and to optimize concerted genetic consultation whenever required. However there are no formal recommendations for referral of these patients to nephrologists and the clinical features of ADPKD at the time of referral remains poorly defined. Methods: This is the baseline survey of a cohort study promoted by investigators in a network of 28 nephrology centers in five regions in Central Italy and the Department of Clinical Epidemiology Institute of Health, Italy. Four hundred and sixty-two incident ADPKD patients were enrolled between February 2013 and April 2014. Results: ADPKD patients in this cohort were referred to nephrologists 6 years (median time) after diagnosis. General Practitioners (GP) were the referring doctors in the 45% of cases. The main drivers of referral were arterial hypertension (21.7%), or the presence CKD (12.3%). The median age in this cohort was 51 years (Interquartile range 42-62), 42% Males. Inheritance was by paternal lineage in 34% and by maternal lineage in 40% cases and unknown in the remaining 26% cases. In 54% of cases the disease was detected because a concerted screening of families of affected individuals. The disease was discovered during a health check-up in 28% of cases and was prompted by the presence of specific symptoms ( pain, hematuria, urine sepsis) in just 18% of cases. When referred to nephrologists, 60% of ADPKD patients were hypertensive. The prevalence of urinary tract infection in this cohort was 28%. Twenty-two percent of patients had nephrolithiasis and microscopic hematuria was detected in 16% of cases. Sixty-seven percent of patients were being treated with ACE-inhibitors at the time of referral and about 1/3 had been screened for cerebral aneurysms by NMR or CT studies. Fifty percent of patients had performed an echocardiogram aimed at detecting LVH or heart valves alterations. Conclusions: In a large geographical area of Central Italy, referral to nephrologists of ADPKD patients occurs about 6 years after diagnosis and the main drivers for referral are hypertension and the presence of CKD. About 1/3 of patients undergo CT or NMR studies of the cerebral circulation and about 50% echocardiography before referral denoting a high degree of suspicion for cerebral aneurysms and LVH by referring physicians. This cohort is being followed up to refine the description of the clinical phenotype of ADPKD, to establish a DNA data bank for genetic epidemiology studies and to model referral patterns and treatment policies in this high risk genetic disease