Renal involvement in sarcoidosis: histological patterns and prognosis, an Italian survey.

BACKGROUND: Granulomatous interstitial nephritis in sarcoidosis (sGIN) is generally clinically silent, but in <1% causes acute kidney injury (AKI). METHODS: This Italian multicentric retrospective study included 39 sarcoidosis-patients with renal involvement at renal biopsy: 31 sGIN-AKI, 5 with other patterns (No-sGIN-AKI), 3 with nephrotic proteinuria. We investigate the predictive value of clinical features, laboratory, radiological parameters and histological patterns regarding steroid response. Primary endpoint: incident chronic kidney disease (CKD) beyond the 1°follow-up (FU) year; secondary endpoint: response at 1°line steroid therapy; combined endpoint: the association of initial steroid response and outcome at the end of FU. RESULTS: Complete recovery in all 5 No-sGIN-AKI-patients, only in 45% (13/29) sGIN-AKI-patients (p=0.046) (one lost in follow-up, for another not available renal function after steroids). Nobody had not response. Primary endpoint of 22 sGIN-AKI subjects: 65% (13/20) starting with normal renal function developed CKD (2/22 had basal CKD; median FU 77 months, 15-300). Combined endpoint: 29% (6/21) had complete recovery and final normal renal function (one with renal relapse), 48% (10/21) had partial recovery and final CKD (3 with renal relapse, of whom one with basal CKD) (p=0.024). Acute onset and hypercalcaemia were associated to milder AKI and better recovery than subacute onset and patients without hypercalcaemia, women had better endpoints than men. Giant cells, severe interstitial infiltrate and interstitial fibrosis seemed negative predictors in terms of endpoints. CONCLUSIONS: sGIN-AKI-patients with no complete recovery at 1°line steroid should be treated with other immunosuppressive to avoid CKD, in particular if males with subacute onset and III stage-not hypercalcaemic AKI.

Contraception in chronic kidney disease: a best practice position statement by the Kidney and Pregnancy Group of the Italian Society of Nephrology.

Even though fertility is reduced, conception and delivery are possible in all stages of CKD. While successful planned pregnancies are increasing, an unwanted pregnancy may have long-lasting deleterious effects, hence the importance of birth control, an issue often disregarded in clinical practice. The evidence summarized in this position statement is mainly derived from the overall population, or other patient categories, in the lack of guidelines specifically addressed to CKD. Oestroprogestagents can be used in early, non-proteinuric CKD, excluding SLE and immunologic disorders, at high risk of thromboembolism and hypertension. Conversely, progestin only is generally safe and its main side effect is intramestrual spotting. Non-medicated intrauterine devices are a good alternative; their use needs to be carefully evaluated in patients at a high risk of pelvic infection, even though the degree of risk remains controversial. Barrier methods, relatively efficacious when correctly used, have few risks, and condoms are the only contraceptives that protect against sexually transmitted diseases. Surgical sterilization is rarely used also because of the risks surgery involves; it is not definitely contraindicated, and may be considered in selected cases. Emergency contraception with high-dose progestins or intrauterine devices is not contraindicated but should be avoided whenever possible, even if far preferable to abortion. Surgical abortion is invasive, but experience with medical abortion in CKD is still limited, especially in the late stages of the disease. In summary, personalized contraception is feasible, safe and should be offered to all CKD women of childbearing age who do not want to get pregnant.

[Psychological Assessment of a sample of women with ADPKD: quality of life, body image, anxiety and depression].

INTRODUCTION: The Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a chronic renal disease that has not yet been the subject of psychological research. There are only a few studies related to the consequences and complications of this pathology on female patients, although women affected by this disease present serious problems. AIM: The purpose of this study is to perform a psychological assessment (quality of life, anxiety, depression, body image) on a sample of 37 women with ADPKD. MATERIALS AND METHODS: The assessment is based on ad hoc social and personal record, KDQOL-SF (to evaluate health-related quality of life), HADS (for anxiety and depression) and BUT (for perceived body image). This assessment is administrated in a specific outpatient clinic. RESULTS: Results show that kidney disease has a negative impact on health-related quality of life. Concerns about body image are linked to anxious and depressive symptomatology: an increase in these concerns is related to a worsening of anxiety and depressive symptoms in patients. Moreover, a higher psychological malaise emerges in hypertensive ADPKD patients, in terms of mood and quality of life, compared to those without this concomitant pathology. Finally, it is important to note that social support, real or perceived, is of paramount importance in maintaining psychological well-being. CONCLUSIONS: The psychological evaluation of ADPKD patients can be used in clinical practice as a supplemental model in multidisciplinary Nephrology team.

Pregnancy in women with diabetic nephropathy.

The number of pregnancies in women with pregestational diabetes has been steadily increasing worldwide. These pregnancies are associated with an increased risk of a variety of complications, including miscarriages, congenital malformations, macrosomia, fetal growth restriction, preeclampsia, preterm delivery and stillbirth. In pregnant women with diabetic nephropathy it is important to evaluate both the effect of pregnancy on kidney function and the effect of kidney disease on pregnancy outcomes. Pregnant women with normal renal function and microalbuminuria have a low risk of loss of kidney function during pregnancy, while women with GFR < 60 ml/min and/or proteinuria ≥ 3 g/24 h at the beginning of pregnancy are at risk of permanent kidney damage. The risk of fetal and maternal complications is associated with the severity of chronic kidney disease and glycemic control. Advances in prenatal care have improved fetal and maternal outcomes and preconception counseling has become key for a successful pregnancy in all women with diabetes and especially in those with diabetes and chronic kidney disease.

Claudin-14 Gene Polymorphisms and Urine Calcium Excretion.

BACKGROUND AND OBJECTIVES: Claudin-16 and -19 are proteins forming pores for the paracellular reabsorption of divalent cations in the ascending limb of Henle loop; conversely, claudin-14 decreases ion permeability of these pores. Single-nucleotide polymorphisms in gene coding for claudin-14 were associated with kidney stones and calcium excretion. This study aimed to explore the association of claudin-14, claudin-16, and claudin-19 single-nucleotide polymorphisms with calcium excretion. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We performed a retrospective observational study of 393 patients with hypertension who were naïve to antihypertensive drugs, in whom we measured 24-hour urine calcium excretion; history of kidney stones was ascertained by interview; 370 of these patients underwent an intravenous 0.9% sodium chloride infusion (2 L in 2 hours) to evaluate the response of calcium excretion in three different 2-hour urine samples collected before, during, and after saline infusion. Genotypes of claudin-14, claudin-16, and claudin-19 were obtained from data of a previous genome-wide association study in the same patients. RESULTS: Thirty-one single-nucleotide polymorphisms of the 3' region of the claudin-14 gene were significantly associated with 24-hour calcium excretion and calcium excretion after saline infusion. The most significant associated single-nucleotide polymorphism was rs219755 (24-hour calcium excretion in GG, 225±124 mg/24 hours; 24-hour calcium excretion in GA, 194±100 mg/24 hours; 24-hour calcium excretion in AA, 124±73 mg/24 hours; P<0.001; calcium excretion during saline infusion in GG, 30±21 mg/2 hours; calcium excretion during saline infusion in GA, 29±18 mg/2 hours; calcium excretion during saline infusion in AA, 17±11 mg/2 hours; P=0.03). No significant associations were found among claudin-16 and claudin-19 single-nucleotide polymorphisms and calcium excretion and between claudin-14, claudin-16, and claudin-19 single-nucleotide polymorphisms and stones. Bioinformatic analysis showed that one single-nucleotide polymorphism at claudin-14 among those associated with calcium excretion may potentially influence splicing of transcript. CONCLUSIONS: Claudin-14 genotype at the 3' region is associated with calcium excretion in 24-hour urine and after the calciuretic stimulus of saline infusion.

Correction to: A best-practice position statement on pregnancy after kidney transplantation: focusing on the unsolved questions. The Kidney and Pregnancy Study Group of the Italian Society of Nephrology.

In the original publication of the article, the first name and last name of the authors were interchanged.

A best-practice position statement on pregnancy after kidney transplantation: focusing on the unsolved questions. The Kidney and Pregnancy Study Group of the Italian Society of Nephrology.

Kidney transplantation (KT) is often considered to be the method best able to restore fertility in a woman with chronic kidney disease (CKD). However, pregnancies in KT are not devoid of risks (in particular prematurity, small for gestational age babies, and the hypertensive disorders of pregnancy). An ideal profile of the potential KT mother includes "normal" or "good" kidney function (usually defined as glomerular filtration rate, GFR ≥ 60 ml/min), scant or no proteinuria (usually defined as below 500 mg/dl), normal or well controlled blood pressure (one drug only and no sign of end-organ damage), no recent acute rejection, good compliance and low-dose immunosuppression, without the use of potentially teratogen drugs (mycophenolic acid and m-Tor inhibitors) and an interval of at least 1-2 years after transplantation. In this setting, there is little if any risk of worsening of the kidney function. Less is known about how to manage "non-ideal" situations, such as a pregnancy a short time after KT, or one in the context of hypertension or a failing kidney. The aim of this position statement by the Kidney and Pregnancy Group of the Italian Society of Nephrology is to review the literature and discuss what is known about the clinical management of CKD after KT, with particular attention to women who start a pregnancy in non-ideal conditions. While the experience in such cases is limited, the risks of worsening the renal function are probably higher in cases with markedly reduced kidney function, and in the presence of proteinuria. Well-controlled hypertension alone seems less relevant for outcomes, even if its effect is probably multiplicative if combined with low GFR and proteinuria. As in other settings of kidney disease, superimposed preeclampsia (PE) is differently defined and this impairs calculating its real incidence. No specific difference between non-teratogen immunosuppressive drugs has been shown, but calcineurin inhibitors have been associated with foetal growth restriction and low birth weight. The clinical choices in cases at high risk for malformations or kidney function impairment (pregnancies under mycophenolic acid or with severe kidney-function impairment) require merging clinical and ethical approaches in which, beside the mother and child dyad, the grafted kidney is a crucial "third element".

[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.

A best practice position statement on the role of the nephrologist in the prevention and follow-up of preeclampsia: the Italian study group on kidney and pregnancy.

Preeclampsia (PE) is a protean syndrome causing a transitory kidney disease, characterised by hypertension and proteinuria, ultimately reversible after delivery. Its prevalence is variously estimated, from 3 to 5% to 10% if all the related disorders, including also pregnancy-induced hypertension (PIH) and HELLP syndrome (haemolysis, increase in liver enzyme, low platelets) are included. Both nephrologists and obstetricians are involved in the management of the disease, according to different protocols, and the clinical management, as well as the role for each specialty, differs worldwide. The increased awareness of the role of chronic kidney disease in pregnancy, complicating up to 3% of pregnancies, and the knowledge that PE is associated with an increased risk for development of CKD later in life have recently increased the interest and redesigned the role of the nephrologists in this context. However, while the heterogeneous definitions of PE, its recent reclassification, an emerging role for biochemical biomarkers, the growing body of epidemiological data and the new potential therapeutic interventions lead to counsel long-term follow-up, the lack of resources for chronic patients and the increasing costs of care limit the potential for preventive actions, and suggest tailoring specific interventional strategies. The aim of the present position statement of the Kidney and Pregnancy Study Group of the Italian Society of Nephrology is to review the literature and to try to identify theoretical and pragmatic bases for an agreed management of PE in the nephrological setting, with particular attention to the prevention of the syndrome (recurrent PE, presence of baseline CKD) and to the organization of the postpartum follow-up.

[Quality of life, anxiety and distress in patients suffering from chronic kidney disease: pre-dialysis and start of dialytic treatment]. / Qualità di vita, ansia e distress nei pazienti affetti da malattia renale cronica: predialisi ed inizio del trattamento dialitico.

The psychological impact of the Chronic Kidney Disease is well known and several factors contribute to a reduction of quality of life, increase of anxiety levels and psychological distress for affected patients. Psychological intervention is becoming ever more consolidating within the Departments of Nephrology. Nevertheless, literature is lacking about the psychological intervention specificity, especially concerning the dialysis and pre-dialysis phase. The purpose of the study is to identify the mainly critical periods for the dialysed patients in terms of anxiety and distress and to examine the impact of medical management in pre-dialysis period on life quality. In this multi-centre study the sample was collected in three Dialysis Centres: the IRCCS San Raffaele, the IRCCS Multimedica and the A.O. Fatebenefratelli. The instruments used were KDQOL-SF, specific for the dialysed patient's quality of life, PDI, for the distress evaluation and STAI, for anxiety evaluation. The data showed the presence of a more severe psychological unease at the beginning of haemodialysis therapy and a better perception of the life quality for those who have received the medical adoption during the pre-dialysis phase than who did not have it. From a psychological point of view, these results highlight the importance of taking charge the patients in a pre-dialysis phase and of structuring specific psychological interventions during the initial period of substitution therapy.

Intestinal Calcium Absorption among Hypercalciuric Patients with or without Calcium Kidney Stones.

BACKGROUND AND OBJECTIVES: Idiopathic hypercalciuria is a frequent defect in calcium kidney stone formers that is associated with high intestinal calcium absorption and osteopenia. Characteristics distinguishing hypercalciuric stone formers from hypercalciuric patients without kidney stone history (HNSFs) are unknown and were explored in our study. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We compared 172 hypercalciuric stone formers with 36 HNSFs retrospectively selected from patients referred to outpatient clinics of the San Raffaele Hospital in Milan from 1998 to 2003. Calcium metabolism and lumbar bone mineral density were analyzed in these patients. A strontium oral load test was performed: strontium was measured in 240-minute urine and serum 30, 60, and 240 minutes after strontium ingestion; serum strontium concentration-time curve and renal strontium clearance were evaluated to estimate absorption and excretion of divalent cations. RESULTS: Serum strontium concentration-time curve (P<0.001) and strontium clearance (4.9±1.3 versus 3.5±2.7 ml/min; P<0.001) were higher in hypercalciuric stone formers than HNSFs, respectively. The serum strontium-time curve was also higher in hypercalciuric stone formers with low bone mineral density (n=42) than in hypercalciuric stone formers with normal bone mineral density (n=130; P=0.03) and HNSFs with low (n=22; P=0.01) or normal bone mineral density (n=14; P=0.02). Strontium clearance was greater in hypercalciuric stone formers with normal bone mineral density (5.3±3.4 ml/min) than in hypercalciuric stone formers and HNSFs with low bone mineral density (3.6±2.5 and 3.1±2.5 ml/min, respectively; P=0.03). Multivariate regression analyses displayed that strontium absorption at 30 minutes was positively associated calcium excretion (P=0.03) and negatively associated with lumbar bone mineral density z score (P=0.001) in hypercalciuric stone formers; furthermore, hypercalciuric patients in the highest quartile of strontium absorption had increased stone production risk (odds ratio, 5.06; 95% confidence interval, 1.2 to 20.9; P=0.03). CONCLUSIONS: High calcium absorption in duodenum and jejunum may expose hypercalciuric patients to the risk of stones because of increased postprandial calcium concentrations in urine and tubular fluid. High calcium absorption may identify patients at risk of bone loss among stone formers.

Impact of European medicines agency recommendations for hypersensitivity reactions on intravenous iron prescription in haemodialysis centres of the Lombardy region.

BACKGROUND: The European Medicines Agency (EMA) has recommended measures to minimize the risk of hypersensitivity reactions (HSRs) to intravenous iron (IVFe). We analysed the effects of these recommendations on IVFe clinical management among haemodialysis centres (HDCs) in Lombardy, Italy. MATERIALS AND METHODS: A questionnaire was sent to all 117 HDCs to collect information on centre characteristics, e.g. HDC type [hospital centre (HC) vs. centre with limited assistance (CAL)], presence/absence of intensive care unit (ICU) and/or emergency trained staff, IVFe therapy regarding molecules, administration modalities, side effects, and percentage variations in iron prescription between 2014 and 2013 (outcome, Δ-IVFe%). A linear regression model was applied to evaluate the focus effect (ß) of HDC type on the outcome, controlling for possible confounding effects of the other characteristics. RESULTS: Response rate was 73.5 %. IVFe therapy was used in 69.1 % (HDC range 11-100) of patients. Following EMA recommendations, prescription was reduced by 12.6 %, with the largest reduction observed in CALs. No severe HSRs were reported. HCs had more frequently an ICU [97.2 vs. 20 %, odds ratio (OR) = 63.6 (95 % confidence interval 15.56; 537.47), p < 0.001], emergency trained staff [97.2 vs. 61.2 %, OR = 10.7 (2.68; 85.33), p < 0.001] and instrumental facilities (91.7 vs. 58 %, OR = 5.8 (2.03; 23.55), p < 0.001] than CALs. Linear regression demonstrated a significant raw effect of HDC type on Δ- IVFe% [ß =  19.6 (9.82; 30.63), p < 0.001]. No association was found when HDC type was adjusted for ICU-presence [ß = 6.7 (-2.32; 18.30), p = 0.199] or for all-confounding factors [ß = 5.6 (-5.50; 17.08), p = 0.337]. CONCLUSIONS: This survey shows a disparity in IVFe therapy prescription following EMA recommendations, which is largely influenced by the presence/absence of ICUs in HD centres.

[Burnout in healthcare professionals: a study carried out in the Nephrology Unit of San Raffaele Hospital]. / Il burnout negli operatori sanitari: uno studio condotto nell'U.O. di Nefrologia dell'Ospedale San Raffaele.

Burnout is a work stress syndrome caused by a prolonged contact with users which present physical and emotional suffering. C. Maslach, one of the main authors, refers that this syndrome is characterized by emotional exhaustion, depersonalization and reduced personal skills. However, the researches done within the Nephrology and Dialysis Departments on this phenomenon are still few in the literature, despite the peculiar characteristics of the care relationship that develops between caregivers and patients on dialysis treatment. The present study aims to highlight the importance of assessing the levels of burnout and strategies of adaptation to stress (coping) in healthcare workers of Nephrology and Dialysis Unit, so that their psychological well-being could be preserved, preventing the possibility of a progressive deterioration of the care relationship with the patient. The implementation of psychological training courses for healthcare workers seems to be a useful tool aimed at the prevention and management of the burnout syndrome.

Generation of Donor-specific T Regulatory Type 1 Cells From Patients on Dialysis for Cell Therapy After Kidney Transplantation.

BACKGROUND: T regulatory type 1 (Tr1) cell-mediated induction of tolerance in preclinical models of transplantation is remarkably effective. The clinical application of such a therapy in patients on dialysis undergoing kidney transplantation should take into account the possible alterations of the immune system observed in these patients. Herein, we aimed at testing the ability to generate donor-specific Tr1 cell-enriched lymphocytes from patients on dialysis on the waiting list for kidney transplantation. METHODS: The Tr1 cell-enriched lymphocytes were generated by coculturing interleukin-10-producing dendritic cells obtained from healthy donors with peripheral blood mononuclear cells (PBMCs) of patients on dialysis, following the same protocol used in a previous cell therapy clinical trial to prevent graft-versus-host disease. Alternatively, purified CD4(+) T cells were used instead of total PBMCs. The ability to generate clinical-grade Tr1 cell-enriched products was defined by testing the reduced response to restimulation with mature dendritic cells generated from the original donor (i.e., anergy assay). RESULTS: The Tr1 cell-enriched medicinal products generated from PBMCs of patients on dialysis showed a low anergic phenotype, incompatible with their eventual clinical application. This was irrespective of HLA matching with the donor or the intrinsically reduced ability to proliferate in response to alloantigens. On the contrary, the use of purified CD4(+) T cells isolated from patients on dialysis led to the generation of a highly anergic donor-specific medicinal product containing an average of 10% Tr1 cells. CONCLUSIONS: The Tr1 cell-enriched medicinal products can be efficiently generated from patients on dialysis by carefully tailoring the protocol on the patients' immunological characteristics.

Risk of nephrolithiasis in primary hyperparathyroidism is associated with two polymorphisms of the calcium-sensing receptor gene.

AIMS: Two single-nucleotide polymorphisms (SNPs) at the calcium-sensing receptor (CASR) gene were previously associated with kidney stones in patients with primary hyperparathyroidism (PHPT): rs1501899, likely associated with a decrease in CASR expression, and Arg990Gly, causing a gain of CASR function. To evaluate the interaction of these two SNPs in the stone risk, we tested the association of stones with the genotype at both SNPs in PHPT patients and the association of rs1501899 with CASR expression as messenger RNA (mRNA) in human kidney samples. METHODS AND RESULTS: Two hundred and ninety-six PHPT patients were genotyped at the rs1501899 and Arg990Gly SNPs. Minor allele frequency at tested SNPs was higher in PHPT stone formers relative to non-stone forming patients. PHPT patients carrying one or two copies of the minor allele at both rs1501899 and Arg990Gly (n = 16) had the maximal risk of stones (odds ratio, OR 8.3) and higher serum ionized calcium compared with homozygous patients for the wild-type allele at both SNPs. CASR expression as mRNA was measured by real time polymerase chain reaction (PCR) in normal kidney medulla samples from 109 subjects. CASR mRNA was significantly lower in medulla samples from homozygotes for the minor allele at rs1501899 than in subjects with other genotypes. CONCLUSIONS: We conclude that the simultaneous presence of the minor allele at rs1501899 and Arg990Gly may amplify the kidney stone risk in PHPT patients, despite their apparently opposite effects on CASR function in the kidney.

[Integration of a psychologist into Nephrology-Dialysis-Hypertension Operative Unit: from needs evaluation to the definition of an intervention model]. / L'inserimento della figura dello psicologo all'interno dell'Unità Operativa di Nefrologia-Dialisi-Ipertensione.

Chronic Kidney Disease (CKD) and the dialytic treatment cause a significant psychological impact on patients, their families and on the medical-nursing staff too. The psychological aspects linked to the chronic condition of Kidney Disease generate the need to integrated a psychologist into the healthcare team of the Nephrology, Dialysis and Hypertension Operative Unit, in order to offer a specific and professional support to the patient during the different stages of the disease, to their caregivers and to the medical team. The aim of this collaboration project between Nephrology and Psychology is to create a global and integrated healthcare model. It does not give attention simply to the physical dimension of patients affected by CKD, but also to the emotional-affective, cognitive and social dimensions and to the health environment.

Decreased transcriptional activity of calcium-sensing receptor gene promoter 1 is associated with calcium nephrolithiasis.

BACKGROUND: CaSR gene is a candidate for calcium nephrolithiasis. Single-nucleotide polymorphisms (SNPs) encompassing its regulatory region were associated with calcium nephrolithiasis. AIMS: We tested SNPs in the CaSR gene regulatory region associated with calcium nephrolithiasis and their effects in kidney. SUBJECTS AND METHODS: One hundred sixty-seven idiopathic calcium stone formers and 214 healthy controls were genotyped for four CaSR gene SNPs identified by bioinformatics analysis as modifying transcription factor binding sites. Strontium excretion after an oral load was tested in 55 stone formers. Transcriptional activity induced by variant alleles at CaSR gene promoters was compared by luciferase reporter gene assay in HEK-293 and HKC-8 cells. CaSR and claudin-14 mRNA levels were measured by real-time PCR in 107 normal kidney medulla samples and compared in patients with different CaSR genotype. RESULTS: Only rs6776158 (A>G), located in the promoter 1, was associated with nephrolithiasis. Its minor G allele was more frequent in stone formers than controls (37.8% vs 26.4%, P = .001). A reduced strontium excretion was observed in GG homozygous stone formers. Luciferase fluorescent activity was lower in cells transfected with the promoter 1 including G allele at rs6776158 than cells transfected with the A allele. CaSR mRNA levels were lower in kidney medulla samples from homozygous carriers for the G allele at rs6776158 than carriers for the A allele. Claudin-14 mRNA levels were also lower in GG homozygous subjects. CONCLUSIONS: Minor allele at rs6776158 may predispose to calcium stones by decreasing transcriptional activity of the CaSR gene promoter 1 and CaSR expression in kidney tubules.

[Hyperparathyroidism as a cardiovascular risk factor in chronic kidney disease: an update from a biological-cellular perspective]. / L'iperparatiroidismo come fattore di rischio cardiovascolare nell'insufficienza renale: un update dal punto di vista biologico-cellulare.

Cardiovascular complications are the main cause of death in patients with chronic kidney disease (CKD). Among these complications, calcific arteriosclerosis and myocardial hypertrophy are the main predictors of cardiovascular morbidity and mortality. Epidemiological studies have shown their association with hyperparathyroidism, which has therefore been included among the non-traditional cardiovascular risk factors. Studies in laboratory animals have shown that PTH administration may induce calcific arteriosclerosis and myocardial hypertrophy. The former develops independently of hyperphosphatemia, but its mechanisms remain unknown. The latter is characterized by increased thickness of the myocardial fibers and especially the fibrous interstitium; its development is influenced by protein kinase C activation and the subsequent increase in cytosolic calcium as well as activation of intracellular signaling pathways inducing protein synthesis and proliferation. Different from these findings, in other studies PTH infusion was able to produce vasodilatation and to favor myocardial cell contraction and regeneration. These effects depend on protein kinase A activation. PTH may produce different and sometimes contradictory functional effects in the arteries and myocardium that are probably related to different experimental or clinical conditions. In patients with CKD and hyperparathyroidism, PTH may be considered a uremic toxin exerting its effects mainly by increasing cellular calcium. Thus, hyperparathyroidism is confirmed to be a target for the conservative therapy of CKD.

Polymorphisms at the regulatory regions of the CASR gene influence stone risk in primary hyperparathyroidism.

BACKGROUND AND OBJECTIVE: Single nucleotide polymorphisms (SNPs) of the calcium-sensing receptor (CASR) gene at the regulatory region were associated with idiopathic calcium nephrolithiasis. To confirm their association with nephrolithiasis, we tested patients with primary hyperparathyroidism (PHPT). DESIGN: A genotype-phenotype association study. METHODS: In all, 332 PHPT patients and 453 healthy controls were genotyped for the rs7652589 (G>A) and rs1501899 (G>A) SNPs sited in the noncoding regulatory region of the CASR gene. Allele, haplotype, and diplotype distribution were compared between PHPT patients and controls, and in stone forming and stone-free PHPT patients. RESULTS: The allele frequency at rs7652589 and rs1501899 SNPs was similar in PHPT patients and controls. The A minor alleles at these two SNPs were more frequent in stone forming (n=157) than in stone-free (n=175) PHPT patients (rs7652589: 36.9 vs 27.1%, P=0.007; rs1501899: 37.1 vs 26.4%, P=0.003). Accordingly, homozygous or heterozygous PHPT patients for the AA haplotype (n=174, AA/AA or AA/GG diplotype) had an increased stone risk (odds ratio 1.83, 95% confidence interval 1.2-2.9, P=0.008). Furthermore, these PHPT patients had higher serum concentrations of ionized calcium and parathyroid hormone (1.50 ± 0.015 mmol/l and 183 ± 12.2 pg/ml) than patients with the GG/GG diplotype (n=145, 1.47 ± 0.011 mmol/l (P=0.04) and 150 ± 11.4 pg/ml (P=0.049)). Using a logistic regression model, the increase in stone risk in PHPT patients was predicted by AA/AA or AA/GG diplotype, the highest tertile of serum ionized calcium values and the lowest tertile of age. CONCLUSIONS: Polymorphisms located in the regulatory region of the CASR gene may increase susceptibility of the PHPT patients to kidney stone production.

Survival and development of cardiovascular disease by modality of treatment in patients with end-stage renal disease.

Patients undergoing dialysis are at high risk for cardiovascular disease (CVD). The aim of this study was to evaluate the influence of hemodialysis (HD) versus peritoneal dialysis (PD) on survival and the risk of developing de novo CVD. Of the 4191 patients with end-stage renal disease (ESRD) who started renal replacement treatment (RRT) in Lombardy between 1994 and 1997, 4064 (who were on dialysis 30 d after the start of RRT) were considered for survival analysis: 2772 were on HD (mean age 60.9 yr; 21.2% diabetic) and 1292 on PD (mean age 63.6 yr; 16% diabetic). The 3120 patients who were free of CVD at the start of RRT were included in the analysis of the risk of developing de novo CVD. HD and PD were compared by use of a Cox-regression proportional hazard model, stratified by diabetic status; the explanatory covariates were age and gender. The death rate was 13.3 per 100 patient-years (13.0 on HD and 13.9 on PD); 197 (6.3%) of the 3120 patients included in the CVD analysis developed de novo CVD (128 on HD and 69 on PD). After adjustment for age, gender, and established CVD and stratification by diabetic status, there was no significant between-treatment difference in 4-yr survival (relative risk [RR], 0.91; 95% confidence interval [CI], 0.79 to 1.06). The risk of de novo CVD did not differ significantly by treatment modality (RR, 1.06; 95% CI, 0.79 to 1.43). The risk of mortality and de novo CVD for new patients with ESRD assigned to HD or PD was similar in Lombardy in the period 1994 through 1997.