A diagnostic-therapeutic pathway for patients with kidney stone disease: 2020 update / Percorso diagnostico-terapeutico per il paziente con calcolosi renale: update 2020

The natural history of urinary kidney stone disease includes the risk of relapses and can be associated with the risk of chronic kidney disease, bone and cardiovascular disease. For this reason, a wide clinical-metabolic assessment of the kidney stone patient is of great importance since the first presentation of the stone, to set an appropriate preventive treatment. The proposed diagnostic-therapeutic pathway includes a careful medical history, in order to highlight a secondary kidney stone disease and the main risk factors for kidney stones, chronic renal disease, or cardiovascular and bone disease; a metabolic evaluation on multiple levels, according to the severity of the disease, and the presence or absence of risk factors, and appropriate instrumental investigations. Thus, the information collected makes it possible to set a preventive treatment consisting of general rules and, if necessary, specific pharmacological or nutritional interventions. This paper has been prepared by the Italian Multidisciplinary Study Group for Kidney Stone Disease, and it is addressed to the several professional figures involved in the management of patients suffering from nephrolithiasis, from the emergency doctor to the general practitioner, urologist, nephrologist, radiologist, and dietician. A diagnostic-therapeutic pathway for patients with kidney stone disease was first published on this Journal in 2010. The present contribution aims at amending and updating the article published exactly ten years ago, to serve as an easy-to-use reference and to guide good clinical practice in this field.

[Dystrophic Calcinosis Cutis: a rare fearsome issue of Chronic Kidney Disease].

Disorders of calcium-phosphate-parathormone balance, are very important issues in ESRD patients, that may lead to severe complications, as dystrophic calcinosis cutis, a rare disease, caused by calcium salt deposits in cutaneous or subcutaneous tissues and many organs. We present the case of a 47 years old woman, in ESRD due to membranous glomerulopathy, treated by peritoneal dialysis, who, after 7 months of dialysis, developed painful masses on second finger and fifth metacarpus of the right hand. Laboratory and instrumental data showed hyperparathyroidism with a parathyroid mass consistent with adenoma. Increasing of therapy with phosphate binders and cinacalcet only, was not effective to solve cutaneous masses, that were biopsied. Histological exam revealed deposition of amorphic material with calcific component, consistent with cutaneous dystrophic calcinosis. We further increased dialysis and therapy and we observed complete regression of masses in 2 months.

Conservative management of chronic kidney disease stage 5: role of angiotensin converting enzyme inhibitors.

BACKGROUND: Benefits and risks of angiotensin converting enzyme inhibitors (ACE-I) in advanced chronic kidney disease (CKD) are controversial. We tested the role of ACE-I in slowing the progression of renal damage in a real-world elderly population with CKD stage 5. METHODS: We evaluated all patients consecutively referred to our CKD stage 5 outpatient clinic from January 2002 to December 2013. Chronicity was defined as two consecutive estimated glomerular filtration rate (eGFR) measurements below 15 ml/min/1.73 m2. We retrieved parameters of interest at baseline and assessed eGFR reduction rate during follow-up. We estimated GFR by the 4-variable Modification of Diet in Renal Disease (MDRD) formula. RESULTS: Mean age of the 342 subjects analyzed was 72 years and eGFR 10 ml/min/1.73 m2. In the 188 patients on ACE-I at baseline, the subsequent annual rate of eGFR reduction was less than a third of that found in the 154 patients off ACE-I. Across phosphate quartiles, baseline eGFR significantly decreased while its annual reduction rate significantly increased. Of the original cohort, 60 patients (17 %) died, 201 (59 %) started dialysis and 81 (24 %) were still in conservative treatment at the end of the study. Multivariate analysis identified age, phosphate, proteinuria, baseline eGFR and its rate of progression as independent risk factors directly or inversely predictive of progression to dialysis. ACE-I use significantly reduced by 31 % the risk of dialysis. CONCLUSIONS: Our study shows that proteinuria independently predicts further renal damage progression even in end-stage renal disease patients not yet in dialysis. In our cohort of elderly patients with very advanced CKD, ACE-I was effective in slowing down further renal damage progression.

High performance of a risk calculator that includes renal function in predicting mortality of hypertensive patients in clinical application.

OBJECTIVE: The aim of this study was to assess the accuracy of a risk calculator that includes renal function as compared with that of the traditional Framingham Risk Score (FRS) in predicting the risk of mortality of hypertensive individuals managed in primary care. METHODS: From the databases of British and Italian General Practitioners, we retrieved demographic and clinical data for 35 101 UK and 27 818 Italian individuals aged 35-74 years with a diagnosis of hypertension. Then, the 5-year incidence of cardiovascular events as well as all-cause and cardiovascular mortality were recorded for both samples. A comparison analysis of the performance of the Individual Data Analysis of Antihypertensive Intervention Trials (INDANA) calculator with that of FRS in predicting 5-year all-cause and cardiovascular mortality risk was made. RESULTS: The INDANA calculator was more accurate than the FRS in predicting all-cause [Δc 0.038, 95% confidence interval (CI) 0.026-0.051 for United Kingdom, and 0.018, 95% CI 0.010-0.027 for Italy, both P < 0.0001] and cardiovascular mortality (Δc 0.050, 95% CI 0.027-0.074 for United Kingdom, and 0.080, 95% CI 0.059-0.101 for Italy, both P < 0.0001). By using the INDANA calculator, 20% of the UK and 10% of the Italian patients were reclassified to higher risk classes for all-cause mortality, and 25 and 28%, respectively were reclassified when cardiovascular mortality was assessed (P < 0.0001 for all). CONCLUSION: The INDANA calculator proved to be more accurate than the FRS in predicting the risk of mortality in hypertensive patients and should be considered for systematic adoption for risk stratification of hypertensive individuals managed in primary care.

Encapsulating peritoneal sclerosis in paediatric peritoneal dialysis patients: the experience of the Italian Registry of Pediatric Chronic Dialysis.

BACKGROUND: Paediatric literature about encapsulating peritoneal sclerosis (EPS) is limited and comes primarily from anecdotic experiences. In this study, we described the incidence and characteristics of EPS in a large paediatric chronic peritoneal dialysis (CPD) patient population. METHODS: We reviewed files of patients starting CPD at <16 years of age, recorded from January 1986 to December 2011 by the Italian Registry of Pediatric Chronic Dialysis (n = 712). Moreover, in December 2011, a survey was performed involving all the Italian Pediatric Nephrology Units to report such EPS cases that occurred after CPD withdrawal. RESULTS: Fourteen EPS cases were reported, resulting in a prevalence of 1.9%. The median age of EPS cases was 4.8 years (range 0.6-14.4) at the start of CPD and 14.3 years (6.5-26.8) at EPS diagnosis. Eleven EPS cases received CPD for longer than 5 years. At diagnosis, nine patients were still on CPD, two were on haemodialysis and three were transplanted. In eight patients, the primary renal disease was represented by glomerulopathy, mainly focal segmental glomerulosclerosis (n = 5). In the last 6 months prior to CPD discontinuation, 10 patients were treated with solutions containing more than 2.27% glucose. Peritonitis incidence was 1:26.8 CPD-months, similar to that calculated in children >12 months of age from the same registry (1:28.3 CPD-months). The mortality rate was 43%. A more aggressive course and an association with calcineurin inhibitors were observed in transplanted patients. CONCLUSIONS: Surveillance for EPS should be maintained in high-risk children who received long-term PD even after years from CPD withdrawal.

Left-ventricular hypertrophy and renal outcome in hypertensive patients in primary-care.

BACKGROUND: Subclinical cardiac damage has recently emerged as a potential predictor of adverse renal outcome. We therefore retrospectively evaluated the effect of left-ventricular hypertrophy (LVH), diagnosed electrocardiographically, on the renal outcome of hypertensive patients managed in primary care. METHODS: From a historical cohort of 39,525 hypertensive individuals evaluated in 2005, we retrieved 5-year data of the 18,510 surviving subjects for whom renal follow-up was available. RESULTS: The baseline prevalences of chronic kidney disease (CKD) and LVH in the study cohort were 25.6% and 5.6%, respectively. During the 5-year follow-up, 1.4% of patients with LVH and 0.5% of those without LVH progressed to end-stage renal disease (ESRD) requiring dialysis (P < 0.01). Moreover, 25.6% of patients with LVH and 17% without LVH progressed from each stage of CKD to a more advanced stage (P < 0.01), whereas 0.9% of patients with LVH and 0.4% without LVH reached stage 5 CKD (P < 0.01). Multivariate Cox regression analysis showed that besides estimated glomerular filtration rate (eGFR) and male gender, LVH was the most significant modifiable predictor of progression to dialysis (hazard ratio (HR), 1.82; 95% CI, 1.05-3.17; P = 0.03). Multivariate logistic regression analysis also revealed LVH as a significant predictor of the risk of progression from each stage of CKD to a more advanced stage (OR, 1.24; 95% CI, 1.07-1.45; P < 0.01), as well as of progression to stage 5 CKD (OR, 1.86; 95% CI, 1.17-2.95; P < 0.01). CONCLUSIONS: Left-ventricular hypertrophy proved to be a significant predictor of adverse renal outcome in hypertensive patients managed with primary care, and systematic screening for LVH should be adopted for assessing renal risk in these patients.

Are current peritoneal dialysis solutions adequate for pediatric use?

Peritoneal dialysis (PD) is the treatment modality of choice in pediatric CKD5D patients awaiting renal transplantation. Facing many decades of renal replacement therapy long term preservation of peritoneal membrane function is of particular importance in this patient group. Whereas conventional PD fluids induce severe morphological and functional alterations of the peritoneal membrane within a few years, reduction of glucose degradation product content by multichamber systems, replacement of glucose by icodextrin and amino acids, and of lactate by bicarbonate at a neutral to physiological pH are expected to preserve peritoneal membrane integrity. Based on numerous in vitro, experimental and clinical studies, the European Pediatric Dialysis Working Group recommended the use of low glucose degradation product solutions whenever possible. Icodextrin is considered a useful option, in particular in children with sodium and water overload, even though infants may absorb higher amounts of icodextrin and achieve less ultrafiltration. The concept of amino acid-based PD fluids is intriguing, but pediatric benefits are insufficiently described and cannot replace tube feeding in malnourished children. Bicarbonate-based PD fluids better control metabolic acidosis and have been recommended in children with acute kidney injury and impaired lactate metabolism. This review discusses the scientific evidence and potential advantages of PD solutions with an improved biocompatibility profile, with a particular focus on pediatric studies.

Case report of the reliability 1,3-ß-D-glucan monitoring during treatment of peritoneal candidiasis in a child receiving continuous peritoneal dialysis.

Fungal peritonitis is an unusual but severe complication of continuous peritoneal dialysis. The role of 1,3-ß-D-glucan is unknown in early diagnosis and in treatment monitoring of peritoneal candidiasis. This case report shows the utility of 1,3-ß-D-glucan monitoring in management of Candida peritonitis in a child undergoing continuous peritoneal dialysis.

CKD awareness and blood pressure control in the primary care hypertensive population.

BACKGROUND: Chronic kidney disease (CKD) is associated with poor renal and cardiovascular outcomes, and early identification largely depends on general practitioners' (GPs') awareness of it. To date, no study has evaluated CKD prevalence in patients with hypertension in primary care. STUDY DESIGN: Cross-sectional evaluation of the Italian GPs' database. SETTING & PARTICIPANTS: 39,525 patients with hypertension representative of the Italian hypertensive population followed up by GPs in 2005. FACTOR: Estimated glomerular filtration rate (eGFR); eGFR <60 mL/min/1.73 m² was defined as CKD. OUTCOMES: GPs' awareness of CKD assessed using International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic codes for CKD, and blood pressure (BP) control. MEASUREMENTS: Data concerning serum creatinine levels, BPs, and antihypertensive medications were obtained for each patient from the GPs' database; eGFR was calculated according to the 4-variable Modification of Diet in Renal Disease (MDRD) Study equation. RESULTS: CKD prevalence was 23%, but kidney disease was diagnosed by GPs in only 3.9% of patients. BP control was inadequate in patients with CKD and those with eGFR >60 mL/min/1.73 m², with only 44% of patients reaching a BP target <140/90 mm Hg and 11% achieving <130/80 mm Hg. Patients with eGFR <60 mL/min/1.73 m² whose GPs were aware of CKD were more likely to reach recommended BP target values (OR, 1.35; 95% CI, 1.15-1.59; P < 0.001). LIMITATIONS: The prevalence of decreased eGFR may be overestimated because of the lack of creatinine calibration. Proteinuria data were not available. CONCLUSIONS: Awareness of CKD by GPs is critical for achieving the recommended guideline BP targets. However, awareness of CKD by GPs is still far too low, highlighting the need to systematically adopt eGFR for more accurate identification of CKD in high-risk populations.

Chronic kidney disease and cardiovascular risk in hypertensive type 2 diabetics: a primary care perspective.

BACKGROUND: Chronic kidney disease (CKD) is associated with poor renal and cardiovascular (CV) outcome, and early identification largely depends on the general practitioners' (GPs) awareness of it. Only a few studies have evaluated the prevalence of CKD in type 2 diabetes in primary care, and no studies are available on hypertensive diabetics. Thus, the aim of this study was to assess the prevalence of CKD and its association with CV morbidity in such a population. METHODS: On the basis of an Italian national project involving GPs and nephrologists, we retrieved demographic, laboratory and clinical data regarding 7582 hypertensive type 2 diabetics (3564 men; age 25-89 years) who were selected using the diagnostic code Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) for diabetes and hypertension. Blood pressure (BP) values, serum creatinine, ECG-diagnosed left ventricular hypertrophy (LVH) and the occurrence of previous major CV events were obtained for each patient from the GPs' Health Search Database. Estimated glomerular filtration rate (GFR) was calculated according to the four-variable MDRD equation. CKD was defined as an estimated GFR < 60 mL/min/ 1.73 m2. RESULTS: CKD prevalence was 26%, although renal disease was diagnosed by GPs in only 5.4% of cases. The prevalence of both LVH and major CV events was 8%. Adequate BP control was only achieved in 10.4% of patients. Patients whose GFR was <60 mL/min/1.73 m2 were older, prevalently female, had increased pulse pressure and higher prevalence of dyslipidaemia. Moreover, the prevalence of both LVH and major CV events was higher in patients with CKD as compared to patients with normal GFR. Multivariate logistic regression analysis showed that patients with CKD had a higher risk of LVH and/or CV events adjusted for eight covariates, and this risk increased by 23% with each 21 mL/min/1.73 m2 decrease in GFR. CONCLUSIONS: This study shows that CKD is highly prevalent in hypertensive type 2 diabetic patients, where it is a strong predictor of CV adverse outcome. However, awareness of CKD by GPs is low. Equations for calculating estimated GFR should be included in the GPs' database in order to detect the presence of CKD and to improve CV outcome of such a high-risk population.