Revisiting nephrocalcinosis: A single-centre perspective. A northern Italian experience.

AIM: Nephrocalcinosis is a clinical-pathological entity characterized by the deposition of calcium salts within the kidney parenchyma. Both the protean presentation and multiple causes may explain the lack of data regarding its prevalence. The aim of this study is to report the prevalence and main clinical features of nephrocalcinosis diagnosed in a newly opened nephrology outpatient unit. METHODS: Analysis on the data we prospectively gathered from the start of activity (2007-2013) was carried out. Clinical and laboratory data were collected from the medical records and from the general laboratory; diagnosis was based upon imaging data reviewed by the same radiologists. RESULTS: Sixty-five of 2695 patients referred to our unit were diagnosed with nephrocalcinosis (2.4%). The affected patients were younger than the overall out-patient population (median: 37.7 (min-max: 8-82) vs 63 years (2-102) P < 0.001), with higher female prevalence (68% vs 51.4%: P < 0.05) and better preserved kidney function (CKD-EPI 103 (23-165) vs 60 mL/min (3.2-169) P < 0.001). Kidney stones were the main reason for referral (35.4%), followed by electrolyte disturbances (22.7%), acute pyelonephritis (4.6%), AKI or CKD (4.6%). Nephrocalcinosis was associated with autoimmune diseases in 29% and with microcythaemia in 23%, while positive family history was present in 23% of patients. Various electrolyte disturbances were observed, with hypercalciuria being the hallmark of beta thalassaemic patients. CONCLUSIONS: Nephrocalcinosis is a rare, but not exceptional disease in nephrology. In Mediterranean countries, microcythaemia would appear to be a major cause of this disease. Greater awareness of nephrocalcinosis is needed for an integrated approach involving various branches of internal medicine and radiology.

Chronic dialysis discontinuation: a systematic narrative review of the literature in the new millennium.

INTRODUCTION AND AIMS: Renal function recovery (RFR), defined as the discontinuation of dialysis after 3 months of replacement therapy, is an uncommon occurrence. At a time when the "too early" start of dialysis is in discussion, a systematic review of the literature for cases in which patients recovered renal function after starting dialysis with chronic indications, including single cases and large series, may lead to attention being focused on this interesting issue. METHODS: The search strategy was built in Medline on Pubmed, in EMBASE and in the Cochrane Collaboration (August 2013) combining Mesh, Emtree and free terms: dialysis or hemodialysis, kidney function, renal function and recovery (publication date 2000-2013). The following tasks were performed in duplicate: titles and abstracts were manually screened, the data were extracted: title, author, objective, year, journal, period of study, multi-center, country, type of study. RESULTS: The systematic review retrieved 1,894 titles; 58 full papers were retrieved and the final selection included 24 papers: 11 case series or Registry data (4 from ANZdata) and 13 case reports. In spite of the high heterogeneity of the studies, overall they suggest that RFR occurs in about 1% of patients, without differences between PD and HD. RFR appears to be more frequent in elderly patients with renal vascular disease (up to 10% RFR in cholesterol emboli or scleroderma), but is reported in all types of primary and secondary kidney diseases. CONCLUSIONS: RFR is a clinical event that should be looked for, particularly in elderly patients with vascular comorbidity.

Tailoring dialysis and resuming low-protein diets may favor chronic dialysis discontinuation: report on three cases.

Renal function recovery (RFR), defined as the discontinuation of dialysis after 3 months of replacement therapy, is reported in about 1% of chronic dialysis patients. The role of personalized, intensive dialysis schedules and of resuming low-protein diets has not been studied to date. This report describes three patients with RFR who were recently treated at a new dialysis unit set up to offer intensive hemodialysis. All three patients were females, aged 73, 75, and 78 years. Kidney disease included vascular-cholesterol emboli, diabetic nephropathy and vascular and dysmetabolic disease. At time of RFR, the patients had been dialysis-dependent from 3 months to 1 year. Dialysis was started with different schedules and was progressively discontinued with a "decremental" policy, progressively decreasing number and duration of the sessions. A moderately restricted low-protein diet (proteins 0.6 g/kg/day) was started immediately after dialysis discontinuation. The most recent update showed that two patients are well off dialysis for 5 and 6 months; the diabetic patient died (sudden death) 3 months after dialysis discontinuation. Within the limits of small numbers, our case series may suggest a role for personalized dialysis treatments and for including low-protein diets in the therapy, in enhancing long-term RFR in elderly dialysis patients.