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Despite being recommended by most guidelines, the metabolic evaluation of patients with nephrolithiasis has limited diffusion due to difficulties relating both to the access to laboratory investigations and to urine collection modalities. Consequently, in addition to the classical 24-h collection, alternative and simplified collection modes have been proposed. We report here on the comparison between metabolic evaluation carried out on 24-h double collection (Lithotest) and overnight spot urines (RF test). Fifty-four patients with stone disease were enrolled, excluding patients with infection or cystine stones. For Lithotest, we measured all analytes necessary to calculate state of saturation (ß) with calcium oxalate, brushite and uric acid, by means of Lithorisk.com. For RF, we measured calcium, magnesium, oxalate, citrate, sulphate, phosphate, pH and creatinine. The comparison was made with creatinine ratios. An estimate of ßCaOx, ßbrushite and ßAU was obtained also on RF urines by using simplified algorithms. We found highly significant correlations between all parameters, despite quite different means. There was a nice correspondence between the two sets of measurements, assessed by the Bland-Altmann test, for calcium, oxalate, citrate, sulphate, urate and pH. Overnight urine had higher saturations compared to 24-h one owing to higher concentration of the former. In conclusion, RF test on overnight urine cannot completely replace Lithotest on 24-hr urine. However, it can represent a simplified tool for either preliminary evaluation or follow-up of patients with stone disease.

BACKGROUND: Recently published guidelines on the medical management of renal stone disease did not address relevant topics in the field of idiopathic calcium nephrolithiasis which are important also for clinical research. DESIGN: A steering committee identified 27 questions which were proposed to a faculty of 44 experts in nephrolithiasis and allied fields. A systematic review of the literature was conducted and 5216 potentially relevant articles were selected; from these 407 articles were deemed to provide useful scientific information. The Faculty divided into working groups analysed the relevant literature. Preliminary statements developed by each group were exhaustively discussed in plenary sessions and approved. RESULTS: Statements were developed to inform clinicians on the identification of secondary forms of calcium nephrolithiasis and systemic complications; on the definition of idiopathic calcium nephrolithiasis; on the use of urinary tests of crystallization and of surgical observations during stone treatment in the management of these patients; on the identification of patients warranting preventive measures; on the role of fluid and nutritional measures and of drugs to prevent recurrent episodes of stones; and finally on the cooperation between the urologist and nephrologist in the renal stone patients. CONCLUSIONS: This document has addressed idiopathic calcium nephrolithiasis from the perspective of a disease that can associate with systemic disorders emphasizing the interplay needed between urologists and nephrologists. It is complementary to the American Urological Association and European Association of Urology guidelines. Future areas for research are identified.

BACKGROUND: Chronic kidney disease (CKD) patients affected by mineral bone disorders (MBD) have higher rates of all-cause and cardiovascular-related mortality. Approximately, one-third of dialysis patients have low serum parathyroid hormone (PTH) levels (≤ 150 pg/mL). However, the reason why these patients have higher mortality compared to patients with normal PTH levels has not yet been fully elucidated. METHODS: The FARO study was performed on 2453 Italian patients followed prospectively from 28 dialysis centres over a 2-year period. Data were collected every 6 months and end points included time-to-death cumulative probability in patients with serum intact PTH (iPTH) ≤ 150 pg/mL and the effect of vitamin D receptor activation (VDRA) therapy. Kaplan-Meier curves and proportional hazards regression models stratified by PTH levels (i.e. ≤ 150 and >150 pg/mL) were used to determine cumulative probability of time-to-death and adjusted hazard ratios (HRs) for demographic, clinical and CKD-MBD treatment characteristics. RESULTS: The cumulative probability of death was higher (P < 0.01) for patients with serum iPTH levels ≤ 150 pg/mL [25.1%, 95% confidence interval (CI): 22.1-28.5 at 18 months] versus those with serum iPTH levels within the normal range (18.0%, 95% CI: 16.1-20.1). In a model with time-dependent covariates restricted to time periods when patients had iPTH levels ≤ 150 pg/mL, lower mortality was observed in patients treated with VDRA [i.e. HR = 0.62, 95% CI: 0.42-0.92 for oral or intravenous (IV) calcitriol; HR = 0.18, 95% CI: 0.04-0.8 for IV paricalcitol] versus those not receiving any VDRA (P < 0.01) independently of other variables. Patients who received IV paricalcitol, compared with either oral or IV calcitriol, showed reduced mortality, but this was not statistically significant (HR = 0.3, 95% CI: 0.07-1.31, P = 0.11). CONCLUSION: Results from this observational study suggest that VDRA therapy was associated with improved survival in dialysis patients, even with low serum iPTH levels.

AIMS: In recent years, treatment options for secondary hyperparathyroidism (SHPT) have increased (e.g., paricalcitol, calcimimetics). To determine the impact these new treatments have on achieving K/DOQI targets, an observational, prospective survey was undertaken. METHODS: Four 6-month time-spaced surveys of 2,637 patients in 28 Italian dialysis units were performed. Patient demographic information; use of vitamin D or calcimimetics; and changes in parathyroid hormone (PTH), calcium (Ca) and phosphate (P) levels were evaluated. RESULTS: Over the course of the survey, use of calcitriol decreased (from 62.1% at baseline to 44.5% at month 18; p

The natural history of urolithiasis includes the risk of recurrence and of the development of chronic kidney and/or bone disease, which is why a thorough clinical and metabolic evaluation of these patients is of the utmost importance at disease onset. This paper is aimed at identifying the type of urolithiasis, the related risk factors, and the corresponding treatment options. The diagnostic and therapeutic approach described here includes 1) accurate history taking to detect secondary nephrolithiasis and screen for the main risk factors for kidney and bone disease; 2) metabolic evaluation graded according to different complexity levels based on the severity of the disease and the presence of risk factors; 3) carrying out appropriate imaging procedures. The resulting information allows to plan treatment based either on general rules of lifestyle and diet, or on selected medical intervention, if necessary. This report, which is based on current guidelines, was produced by the Gruppo Italiano di Studio Multidisciplinare per la Calcolosi Renale. It is addressed to all professionals involved in the management of patients suffering from nephrolithiasis, first of all general practitioners, who often become involved immediately at the onset of the disease.

Background: Mineral Bone Disorders (MBD) is prevalent in hemodialysis (HD) patients and associated with increased cardiovascular mortality. The FARO-2 study evaluated the achievement of the NKF/K-DOQI guidelines on recommended target values for serum calcium (Ca), phosphorous (P) and intact parathyroid hormone (PTH) levels on survival in incident HD patients. Methods: Data were collected by questionnaire from 568 incident HD patients followed prospectively over a 3-year period from 26 Italian dialysis units. The cumulative probability of time-to-death for CKD-MBD treatment characteristics was determined by the Kaplan-Meier curves. Results: Serum PTH levels (median values at 6 months vs. 36 months; 225 vs. 254 pg/ml), Ca (8.8 vs. 8.9 g/dl) and P (5.1 vs. 4.8 mg/dl) were not significantly different at 6 months versus follow-up. The majority of incident HD patients (60-70%) who were followed up for 36 months did not achieve the NKF/K-DOQI recommended target values. Survival rates were higher in patients on target for three parameters versus patients off target (survival at 24 months: at target 95.7% (95% CI: 84.0-98.9) versus not on target 71.1% (95% CI: 66.3-75.4, p < 0.01)). The 30.1% of patients on target for three MBD parameters at least once during the follow-up period had better survival rates compared to those not reaching these targets (survival at 24 months: at least once 88.0% (95% CI: 81.9-92.1); 67.7% (95% CI: 61.9-72.8, p < 0.01)). Conclusion: Our findings indicate that incident HD patients who achieved target levels (for three MBD parameters) for at least one visit have a lower risk of mortality.

BACKGROUND: Chronic kidney disease (CKD) patients affected by mineral bone disorders (MBD) have higher rates of all-cause and cardiovascular-related mortality. Approximately, one-third of dialysis patients have low serum parathyroid hormone (PTH) levels (≤ 150 pg/mL). However, the reason why these patients have higher mortality compared to patients with normal PTH levels has not yet been fully elucidated. METHODS: The FARO study was performed on 2453 Italian patients followed prospectively from 28 dialysis centres over a 2-year period. Data were collected every 6 months and end points included time-to-death cumulative probability in patients with serum intact PTH (iPTH) ≤ 150 pg/mL and the effect of vitamin D receptor activation (VDRA) therapy. Kaplan-Meier curves and proportional hazards regression models stratified by PTH levels (i.e. ≤ 150 and >150 pg/mL) were used to determine cumulative probability of time-to-death and adjusted hazard ratios (HRs) for demographic, clinical and CKD-MBD treatment characteristics. RESULTS: The cumulative probability of death was higher (P < 0.01) for patients with serum iPTH levels ≤ 150 pg/mL [25.1%, 95% confidence interval (CI): 22.1-28.5 at 18 months] versus those with serum iPTH levels within the normal range (18.0%, 95% CI: 16.1-20.1). In a model with time-dependent covariates restricted to time periods when patients had iPTH levels ≤ 150 pg/mL, lower mortality was observed in patients treated with VDRA [i.e. HR = 0.62, 95% CI: 0.42-0.92 for oral or intravenous (IV) calcitriol; HR = 0.18, 95% CI: 0.04-0.8 for IV paricalcitol] versus those not receiving any VDRA (P < 0.01) independently of other variables. Patients who received IV paricalcitol, compared with either oral or IV calcitriol, showed reduced mortality, but this was not statistically significant (HR = 0.3, 95% CI: 0.07-1.31, P = 0.11). CONCLUSION: Results from this observational study suggest that VDRA therapy was associated with improved survival in dialysis patients, even with low serum iPTH levels.

Systematic screening using the SSCP technique followed by sequencing of bands with abnormal mobility derived from the AGXT exons of 15 unrelated Italian patients with primary hyperoxaluria type 1 (PH1) allowed us to characterize both the mutant alleles in each individual. Eight new mutations were identified: C155del, C156ins, G244T, C252T, GAG408ins, G468A, G588A and G1098del. This study demonstrates both the effectiveness of the screening strategy chosen to identify all the mutant alleles and the high degree of allelic heterogeneity in PH1.