[Clozapine-induced Tubulointerstitial Nephritis].

Tubulointerstitial nephritis is a common cause of acute renal failure, in two thirds of cases it is associated with drugs (mostly antimicrobials and NSAIDs), in 5-10% of cases it is associated with infections (bacterial/viral/parasitic), in 5-10% of cases it is idiopathic (this is the case of the TINU syndrome characterized by interstitial nephritis and bilateral uveitis, and the anti-glomerular basal membrane antibody syndrome), and finally in 10% of cases it is associated with systemic diseases (sarcoidosis, by Sjogren, LES). The pathogenesis is based on a cell-mediated immune response and in most cases removing the causative agent is the gold standard of therapy. However, a percentage of patients, in a variable range from 30% to 70% of cases, do not fully recover renal function, due to the rapid transformation of the interstitial cell infiltrate into vast areas of fibrosis. Clozapine is a second generation atypical antipsycothic usually used for the treatment of schizophrenia resistant to other types of treatment; it can cause severe adverse effects among which the best known is a severe and potentially fatal neutropenia, furthermore a series of uncommon adverse events are recognized including hepatitis, pancreatitis, vasculitis. Cases of acute interstitial tubular nephritis associated with the use of clozapine have been described in the literature, although this complication is rare. Medical personnel using this drug need to be aware of this potential and serious side effect. We describe the case of a 48-year-old man who developed acute renal failure after initiation of clozapine.

[Clinical practice for the diagnosis of cardiac arrhythmias in patients on renal replacement therapy: data from a Lombard survey]. / Pratica clinica per la diagnostica delle aritmie cardiache in pazienti in terapia renale sostitutiva: dati di una survey lombarda.

Among dialysis patients, 40% of deaths are due to cardiovascular causes, and 60% of cardiac deaths are due to an arrhythmia. The purpose of this survey, carried out with the organizational support of the Lombard Section of the Italian Society of Nephrology, is to evaluate the frequency and mode of use of non-invasive instruments for the diagnosis of cardiac arrhythmias in the dialysis centers of Lombardy. Information on the prevalence and type of cardiac devices at December 1, 2016 in this population was also required. Data from 18 centers were collected for a total of 3395 patients in replacement renal therapy, including 2907 (85.6%) in hemodialysis and 488 (14.4%) in peritoneal dialysis. All centers use the 12-lead ECG in case of evocative symptoms of an arrhythmic event and 2/3 perform the exam with programmed cadence (usually once a year). Twenty four-hour ECG Holter is not used as a routine diagnostic tool. The proportion of cardiac devices is relatively high, compared to literature data: n=259, equal to 7.6% of the population. Pace-Maker patients are 166 (4.9%), those with intracardiac defibrillator 52 (1.5%), those with resynchronization therapy 18 (0.5%) and those with resynchronization therapy and intracardiac defibrillator 23 (0.7%). The survey provides interesting information and can be an important starting point for trying to optimize clinical practice and collaboration between nephrologists and cardiologists in front of a major problem like that of arrhythmic disease in patients on renal replacement therapy.

KCNA1 and TRPC6 ion channels and NHE1 exchanger operate the biological outcome of HGF/scatter factor in renal tubular cells.

Hepatocyte growth factor (HGF) is a glycoprotein that induces in vitro epithelial tubular cell growth, motility, scattering and branching morphogenesis. The cell machineries that account for HGF biological effects are still unclear. In previous study, we found that HGF upregulated in epithelial tubular cell line (HK2) 3 genes: potassium channel KCNA1, calcium channel (transient receptor potential channel, subfamily C, member 6, TRPC6) and Na(+)/H(+) exchanger-1 (NHE1). In this study, we validated these results with reverse transcription PCR and WB analysis. To investigate whether KCNA1, TRPC6, NHE1 mediate the changes induced by HGF in HK2, we studied the effects of their inhibitors: 4-aminopyridine, charybdotoxin, dendrotoxin K inhibitors of KCNA1, lanthanum, N-(p-amylcinnamoyl) anthranilic acid inhibitors of TRPC6, 5-(N-ethyl-N-isopropyl)amiloride, cariporide inhibitors of NHE1. The inhibitors prevented HGF-induced growth, migration, cytoskeletal reorganization and tubulogenesis in HK2. These results indicate that KCNA1, TRPC6 and NHE1 are cell machineries that are exploited by HGF to effect its biological outcome in renal tubular cells.