[The Outpatient Activity of the Onconephrology Clinic of Cremona in the First Semester of 2023]

Despite the rapidly growing area of onconephrology in the last decade, nephropathic patients have been rarely involved in clinical trials of cancer therapy, particularly in the case of chronic kidney disease (CKD) stage 4 (CKD4) or stage 5 (CKD5). We could offer better therapeutic opportunities to our patients thanks to the Onconephrology Clinic and the Multidisciplinary group, in which a dedicated team of specialists guarantees the highest level of possible care. In this paper, we analysed the activity of the first Italian OnconephrologyClinic, twelve years after its foundation. We studied retrospectively a cohort of 174 patients referred to our center in the last six months (from 11/01/2023 to 12/07/2023), with a total of 262 visits (40 first visits). We highlight a prevalence of moderated or advanced kidney disease, in contrast with the literature, which is probably the result of a transversal II level clinic with different specialists involved. Furthermore, in patients with a prolonged follow-up, we observed a progressive better attention to every kidney involvement, particularly in patients in active cancer therapy, by the oncologist colleagues. We observed a reduction of treatment withdrawals due to kidney toxicity, thanks to a multidisciplinary approach and experienced-based management. On the other side, we highlight also a delayed addressing of patients with acute kidney injury (AKI), which often results in chronic kidney damage. This could be related to a delayed identification of the reduced renal function, which is difficult to correctly value in patients with cancer.

[Staphylococcus-associated glomerulonephritis without IgA deposits: a case report]

Staphylococcus-associated glomerulonephritis (SAGN) represents a possible version of parainfectious glomerulonephritis and is a pathological entity that's now constantly increasing in developed countries. It is known how bacterial infections can be a possible trigger for various type of glomerulonephritis with clinical onset and evolution comparable to the ones observed in parainfectious glomerulonephritis. Furthermore, in clinical practice the identification and isolation of the pathogenic microorganism responsible for the development of parainfectious glomerulonephritis is not always possible. Therefore, in those cases in which SAGN is suspected, it is often necessary to recur to kidney biopsy in order to come to as much as possible correct diagnosis. Historically, according to scientific literature, the most distinctive anatomopathological feature of SAGN is represented by predominant or codominant mesangial IgA deposits, sometimes associated with C3 deposits. These findings make the differential diagnosis between SAGN and IgA nephropathy often necessary. However, many reports describe how SAGN can also be characterized by a varying spectrum of immunological deposits. In some cases, for example, IgA deposits can be absent and in some other cases it is described a net dominance of C3 deposits. In this case, it becomes extremely important to exclude a possible occurrence of C3 glomerulopathy (C3GN), considering how different are the therapeutic approach and the prognostic implications associated to it. However, the differential diagnosis between SAGN and C3GN can be very hard. Here's a case report about a patient who has been hospitalized into our Unit after developing a form of Staphylococcus Aureus associated glomerulonephritis which presented atypical anatomopathological features.

Time for Revival of Bone Biopsy with Histomorphometric Analysis in Chronic Kidney Disease (CKD): Moving from Skepticism to Pragmatism

Bone Biopsy (BB) with histomorphometric analysis still represents the gold standard for the diagnosis and classification of different forms of renal osteodystrophy. Bone biopsy is the only technique able to provide comprehensive information on all bone parameters, measuring static and dynamic parameters of turnover, cortical and trabecular microarchitecture, and mineralization defects. In nephrological practice, bone biopsy yields relevant indications to support therapeutic choices in CKD, heavily impacting the management and prognosis of uremic patients. Unfortunately, the use of bone biopsy has decreased; a lack of expertise in performing and interpreting, perceived procedure invasiveness and pain, and reimbursement issues have all contributed to this decline. Nevertheless, both bone biomarkers and instrumental images cannot be considered reliable surrogates for histological findings, being insufficiently accurate to properly evaluate underlying mineral and bone disorders. This is a multidisciplinary position paper from the Nephrology and Osteoporosis Italian Scientific Societies with the purpose of restating the role of bone biopsy in CKD patient management and of providing strong solutions to allow diffusion of this technique in Italy, but potentially also in other countries. The Italian approach through the optimization and standardization of bone biopsy procedure, the construction of the Italian Hub and Spoke network, and a request for adjustment and national homogenization of reimbursement to the Italian Health Ministry has led the way to implement bone biopsy and to improve CKD patient management and prognosis.

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.

Combined renal proximal tubulopathy and crystal storing histiocytosis in a patient with κ light chain multiple myeloma

Multiple myeloma accounts for 10-15% of all hematologic malignancies, and 20% of deaths related to cancers of the blood and bone marrow. Diagnosis is defined by the presence of a serum monoclonal spike (M-spike) of more than 3 g/dL or more than 10% clonal plasma cells in the bone marrow and at least one myeloma-defining event, such as hypercalcemia, anemia, bone lesions, or renal impairment. The kidney is a major target organ, and renal impairment is frequently the first manifestation of the disease. Renal damage occurs in up to 40% of patients and 10-20% will require dialysis. Monoclonal immunoglobulin light chains are the major causes of renal complications in multiple myeloma. Glomerular disease, with the deposition of monoclonal immunoglobulins or their components, includes monoclonal immunoglobulin deposition disease, AL or AH amyloidosis, type I cryoglobulinemia, proliferative glomerulonephritis with monoclonal IgG deposits, immunotactoid glomerulopathy, and fibrillary glomerulonephritis. In addition, tubulointerstitial diseases with the deposition of monoclonal immunoglobulins or their components, are constituted by light chain cast nephropathy, light chain proximal tubulopathy, and crystal-storing histiocytosis.

We report the case of a 66-year-old woman who presented with albumin-predominant moderate proteinuria and renal failure. Serum and urine immunofixation electrophoresis showed monoclonal κ light chain in both. Renal biopsy confirmed κ-restricted crystal-storing renal disease involving proximal tubular epithelial cells and crystal storing histiocytosis. Multiple myeloma with crystal storing histiocytosis was discovered in bone marrow biopsy. Thus, we present an unusual case of a myeloma patient presenting light chain proximal tubulopathy and crystal-storing histiocytosis both in the kidney and in the bone marrow.

Canakinumab as treatment for COVID-19-related pneumonia: A prospective case-control study

OBJECTIVES

Canakinumab is an IL-1β antibody that neutralises the activity of IL-1β. This study examined the efficacy and safety of canakinumab in patients with moderate COVID-19-related pneumonia.

DESIGN

This study aimed to evaluate the reduction in duration of hospitalisation with adequate oxygen status. Forty-eight patients with moderate COVID-19-related pneumonia were asked to participate in the prospective case-control study: 33 patients (cases) signed informed consent and received canakinumab (Cohort 1) and 15 patients (Controls) refused to receive the experimental drug and received institutional standard of care (Cohort 2).

RESULTS

Hospital discharge within 21 days was seen in 63% of patients in Cohort 1 vs. 0% in Cohort 2 (median 14 vs. 26 days, respectively; p < 0.001). There was significant clinical improvement in ventilation regimes following administration of canakinumab compared with Cohort 2 (Stuart-Maxwell test for paired data, p < 0.001). Patients treated with canakinumab experienced a significant increase in PaO2:FiO2 (p < 0.001) and reduction in lung damage by CT (p = 0.01), along with significant decreases in immune/inflammation markers that were not observed in Cohort 2. Only mild side-effects were seen in patients treated with canakinumab; survival at 60 days was 90.0% (95% CI 71.9-96.7) in patients treated with canakinumab and 73.3% (95% CI 43.6-89.1) for Cohort 2.

CONCLUSIONS

Treatment with canakinumab in patients with COVID-19-related pneumonia rapidly restored normal oxygen status, decreased the need for invasive mechanical ventilation, and was associated with earlier hospital discharge and favourable prognosis versus standard of care.

[Kidney involvement in Waldenström's disease - case report]

Waldenström's disease is a rare haematological neoplasm involving B lymphocytes, characterized by medullary infiltrated lymphoplasmacytic lymphoma and by the presence of a monoclonal M paraprotein. Although rarely, this condition may lead to heterogeneous renal involvement and cause severe renal failure. We report the clinical case of a patient with overt nephrotic syndrome in Waldenström's disease treated with a combination chemotherapy (rituximab, cyclophosphamide, dexamethasone) until complete renal and haematological remission.

Kidney transplant patients with SARS-CoV-2 infection: The Brescia Renal COVID task force experience

The outcome of kidney transplant patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is still unclear. Here we describe the clinical characteristics, disease outcome, and risk factors for acute respiratory distress syndrome (ARDS) and death of a cohort of 53 kidney transplant patients with coronavirus disease 2019 (COVID-19). Eight of 53 have been handled as outpatients because of mild disease, on average with immunosuppression reduction and the addition of hydroxychloroquine and azithromycin; no patients required admission, developed ARDS, or died. Because of severe symptoms, 45/53 required admission: this cohort has been managed with immunosuppression withdrawal, methylprednisolone 16 mg/d, hydroxychloroquine, and antiviral drugs. Dexamethasone and tocilizumab were considered in case of ARDS. About 33% of the patients developed acute kidney injury, 60% ARDS, and 33% died. In this group, thrombocytopenia was associated to ARDS whereas lymphopenia at the baseline, higher D-dimer, and lack of C-reactive protein reduction were associated with risk of death. In the overall population, dyspnea was associated with the risk of ARDS and age older than 60 years and dyspnea were associated with the risk of death with only a trend toward an increased risk of death for patients on tacrolimus. In conclusion, SARS-CoV-2 infection may have a variable outcome in renal transplant patients, with higher risk of ARDS and death in the ones requiring admission.

Overweight-obesity is associated with decreased vitamin K2 levels in hemodialysis patients

OBJECTIVES

Obesity is an important risk factor for morbidity and mortality. Vitamin K2 is involved in the production of bone and matrix amino acid g-carboxy-glutamic acid (Gla) proteins (vitamin K-dependent proteins [VKDPs]), regulating bone and vascular calcification (VC). Bone Gla protein (BGP) is involved both in bone mineralization and VCs. We assessed the relationships between vitamin K levels and body mass index (BMI) according to the hypothesis that the impact of BMI on mortality is partly driven by low vitamin K levels.

METHODS

The Vitamin K Italian (VIKI) study included 387 hemodialysis patients from 18 dialysis centers in Italy. We determined plasma levels of bone markers: vitamin K levels, VKDPs, vitamin 25(OH)D, alkaline phosphatase (ALP), parathyroid hormone (PTH), calcium (Ca), phosphorus (P) and routine biochemistry. BMI was classified into the following categories: underweight (BMI < 18.5 kg/m²), normal weight (18.5 ≤ BMI < 25 kg/m²), overweight (25 ≤ BMI < 30 kg/m²) and obese (BMI ≥ 30 kg/m²).

RESULTS

45.2% of patients were overweight or obese. Stratification by BMI demonstrated lower median menaquinone-7 (MK7)/triglycerides levels in obese patients (0.42 ng/mg [0.19, 0.87], p = 0.005). BGP levels were lower in overweight and obese patients (152 mcg/L [83.2, 251] and 104 mcg/L [62.7, 230], p = <0.001). Furthermore, there was an inverse correlation between MK7/triglycerides levels and BMI (regression coefficient β = -0.159; p = 0.003). In multiple linear regression, there was an inverse relationship between BGP levels and BMI (β = - 0.119; p = 0.012).

CONCLUSIONS

These data are the first to report an inverse relationship between Vitamin K2 levels and BMI in hemodialysis patients. Further studies are needed to confirm these findings and to determine if lower levels of Vitamin K are related to greater morbidity and mortality in this at-risk population.

Management of Patients on Dialysis and With Kidney Transplantation During the SARS-CoV-2 (COVID-19) Pandemic in Brescia, Italy

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as coronavirus disease (COVID-19), is a major pandemic challenging health care systems around the world. The optimal management of patients infected with COVID-19 is still unclear, although the consensus is moving toward the need of a biphasic approach. During the first phase of the disease (from onset of the symptoms up to 7-10 days) viral-induced effects are prominent, with the opportunity to institute antiviral therapy. In the second inflammatory phase of the disease, immunosuppressive strategies (for example with glucocorticoids or anticytokine drugs) may be considered. This latter stage is characterized by the development of progressive lung involvement with increasing oxygen requirements and occasionally signs of the hemophagocytic syndrome. The management of the disease in patients with kidney disease is even more challenging, especially in those who are immunosuppressed or with severe comorbidities. Here we present the therapeutic approach used in Brescia (Italy) for managing patients infected with COVID-19 who underwent kidney transplantation and are receiving hemodialysis. Furthermore, we provide some clinical and physiopathological background, as well as preliminary outcome data of our cohort, to better clarify the pathogenesis of the disease and clinical management.

[Managing patients in dialysis and with kidney transplant infected with Covid-19]

We are in the midst of a health emergency that is totally new for us all and that requires a concerted effort, especially when it comes to safeguarding patients on hemodialysis, and kidney transplant recipients. Brescia is currently a very active cluster of infections (2918 cases on the 17/03/2020), second only to Bergamo. The way our structure is organised has allowed us to treat nephropathic patients directly within the Nephrology Unit, following of course a great deal of reshuffling; at the moment, we are treating 21 transplanted patients and 17 on hemodialysis. This has led us to adopt a systematic approach to handling this emergency, not only in managing inpatients, but also in researching the new disease. Our approach is mirrored in the guidelines attached to this article, originally intended for internal use only but potentially very useful to our colleagues, as they face the same exact problems. We have also started collecting data on our positive patients with the aim of understanding better the functioning of this disease and how best to manage it. If anyone is interested, we ask you to please get in touch with us, so we can coordinate our efforts.

Survival of Diabetic Patients on Peritoneal Dialysis Or Hemodialysis

Our objective was to analyze the survival of diabetic patients on renal replacement therapy and to compare their survival on extracorporeal and on peritoneal dialysis. All data regarding diabetic patients admitted to dialysis between 1 January 1983 and 31 December 1993 were collected by means of individual patient questionnaires sent to all of the 44 regional Renal Units (100% answers) of Lombardy, Italy. Cox proportional hazards model, stepwise procedure, was applied in order to select the covariates significantly associated with survival. Age (at baseline), sex, type of diabetes, initial modality of treatment (hemodialysis or peritoneal dialysis), and initial clinical risk factors (malignancies, serious heart disease, vascular disease, cirrhosis of the liver, cachexia) were considered. Descriptive analysis of survival was performed using the Kaplan-Meier technique. The survival of all diabetic patients (895) was 86.5% at one year, 52% at three years, an d 34% at five years. The main causes of the 488 deaths of diabetic patients were cardiovascular diseases (56%), cachexia (18%), and infections (11%). The relative death risk of patients on peritoneal dialysis versus those on hemodialysis, after taking into account the main comorbid conditions, did not significantly differ from 1, as estimated by the Cox proportional hazards regression model. Five-year survival of diabetic patients was 34%, and no differences were found between peritoneal dialysis and hemodialysis as far as mortality is concerned.

The Sigmoidal Parathyroid Hormone-Ionized Calcium Curve and the Set Point of Calcium in Hemodialysis and Continuous Ambulatory Peritoneal Dialysis

A high Incidence of adynamic bone disease not related to aluminum Intoxication has been reported In continuous ambulatory peritoneal dialysis (CAPD). Since reduced parathyroid hormone (PTH) secretion may predispose to adynamic bone, we Investigated whether parathyroid gland sensitivity may be depressed In CAPD in comparison with hemodialysis (HD). Thus we determined parathyraid function by the evaluation of the PTH-ionized calcium (ICa) relationship, which was obtained Inducing hypocalcemia and hypercalcemia In 19 CAPD and 18 HD patients with biochemical and histological evidence of mild (MILD) or severe (OF) hyperparathyroidism, but negative stainable bone aluminum. Either CAPD or HD patients with OF showed a shift to the right of the sigmoidal PTH-ICa curve in comparison with patients with MILD, greater set point of calcium, and maximal PTH stimulation and Inhibition. The PTH-lCa curve and the other parathyraid function parameters were not different in CAPD and HD patients within the same bone histological group. In conclusion, our data document that parathyroid gland activity Is stimulated either in CAPD and HD patients with OF, but is not depressed in CAPD patients in comparison with HD patients.

New scenarios in secondary hyperparathyroidism: etelcalcetide. Position paper of working group on CKD-MBD of the Italian Society of Nephrology

Bone mineral abnormalities (defined as Chronic Kidney Disease Mineral Bone Disorder; CKD-MBD) are prevalent and associated with a substantial risk burden and poor prognosis in CKD population. Several lines of evidence support the notion that a large proportion of patients receiving maintenance dialysis experience a suboptimal biochemical control of CKD-MBD. Although no study has ever demonstrated conclusively that CKD-MBD control is associated with improved survival, an expanding therapeutic armamentarium is available to correct bone mineral abnormalities. In this position paper of Lombardy Nephrologists, a summary of the state of art of CKD-MBD as well as a summary of the unmet clinical needs will be provided. Furthermore, this position paper will focus on the potential and drawbacks of a new injectable calcimimetic, etelcalcetide, a drug available in Italy since few months ago.

[Hyperphosphatemia in dialysis: which binder?]

Several studies have evidenced the association between high serum phosphorus concentrations and adverse events especially in patients on dialysis. Recent K-DIGO guidelines suggest lowering elevated phosphate levels toward the normal range. This goal should be achieved by combining dietary counseling, optimizing dialysis procedures and prescribing phosphate binders. Despite the availability of several binders, the "ideal" phosphate binder that combines high efficacy, low pills burden, minimal side effects and low cost is still not available. In clinical practice it is crucial to reach a high patient's compliance to therapy. The pill burden is the most relevant factor contributing to low compliance. This is the case of phosphate binder therapy that represents almost 50% of total pills prescribed to patients on dialysis. It has been evidenced an association between pills of phosphate binder and poor control of phosphorus and PTH. In recent years sucroferric oxyhydroxide is available as a new phosphate binder. Its peculiarity is an high phosphate binding capability that requires prescription of low number of pills per day. This characteristic has been confirmed by several randomized controlled trials. These trials have also evidenced that sucroferric oxyhydroxide may cause some gastrointestinal side effects. There is an ongoing study to confirm in "the real world" the incidence of side effects reported by controlled trials.

[New scenarios in secondary hyperparathyroidism: etelcalcetide. Position paper of Nephrologists form Lombardy]

Bone mineral abnormalities (defined as Chronic Kidney Disease Mineral Bone Disorder; CKD-MBD) are prevalent and associated with a substantial risk burden and poor prognosis in CKD population. Several lines of evidence support the notion that a large proportion of patients receiving maintenance dialysis experience a suboptimal biochemical control of CKD-MBD. Although no study has ever demonstrated conclusively that CKD-MBD control is associated with improved survival, an expanding therapeutic armamentarium is available to correct bone mineral abnormalities. In this position paper of Lombardy Nephrologists, a summary of the state of art of CKD-MBD as well as a summary of the unmet clinical needs will be provided. Furthermore, this position paper will focus on the potential and drawbacks of a new injectable calcimimetic, etelcalcetide, a drug available in Italy since few months ago.

Early Failure Rates of Arterovenous Fistulas for Hemodialysis: Evaluation of Six-Year Activity

Maintenance and complications of vascular access (VA) for hemodialysis (HD) represent the leading cause of morbidity and health care cost among end stage renal disease population.

To define the reasons for the use of a particular VA at the beginning of replacement treatment, we prospectively evaluated the early failure rate and survival of arterovenous fistula (AVF) in 183 patients. These patients had high prevalence of cardiovascular risk factors and co-morbid conditions, and began HD in our renal unit from the 1st of January 1995. As a part of this study the present analysis focuses on potential predictors of early failure of the first AVF (within the first 7 days after the operation).

Overall, 279 AVF were prepared: 193 at the wrist and 86 at the upper arm, including 11 prosthetic grafts; 150 patients (82%) were given a distal AVF in the first operation. Our conservative policy resulted in a relatively high prevalence of native AVF in use among our prevalent HD patients (84.3%).

Early failure of the first VA was 10.4%. Multivariate analysis showed that this event was neither significantly associated with all traditional risk factors and co-morbids tested, nor with the operating surgeon.

We conclude that in this prospectively studied cohort, the high rate of native AVF created in order to preserve the vascular bed, though associated with a high early failure rate unaffected by traditional cardiovascular risk factors, resulted in a low proportion of permanent catheters and arterovenous grafts in use among prevalent HD patients.

Von Willebrand Factor and Autoantibodies against Oxidized LDL in Hemodialysis Patients Treated with Vitamin E-Modified Dialyzers

Oxidant stress is a well known cause of damage in the atherosclerotic process. Vitamin E is one of the most promising natural antioxidants. In this study we investigated if a vitamin E-coated dialyzer was able to reduce the plasma levels of auto-antibodies against oxidized-LDL, von Willebrand factor (vWf) and thrombomodulin (TM) as markers of endothelial damage.

In this controlled 6-month prospective study, we investigated these markers in two matched groups (n= 16 each) of patients on regular hemodialysis not yet diagnosed for atherosclerosis cardiovascular disease (ACVD) (mean age= 58.3±7.0 yrs, mean dialysis age = 30.1±10.0 months), in which cellulosic (CLS) and vitamin E-modified dialyzers (CLE) were compared. At inclusion all the patients were treated with CLS. Then, the study group was shifted to CLE for 6 months.

At baseline the patients showed normal levels of vitamin E and high levels of oxLDL-Ab, vWf and TM compared to healthy subjects. In the CLE group oxLDL-Ab and vWf, but not TM levels, decreased progressively (from 472±287 to 264±199 mU/mL, p<0.0001 and from 101.1±7.5% to 76.7±18.5%; p<0.001, respectively), and vitamin E increased from 4.40±0.81 to 7.81±1.16 μg/mg of cholesterol. At the end of the study, 8 of the patients treated with CLE were randomly selected and went back to the membrane without Vitamin E for six months. They showed an significant increase in OxLDL-Ab and vWf levels and a significant reduction in tocoferol levels. In conclusion, CLE compared to cellulosic dialyzers can lower some indices of damage to LDL and endothelial cells.

[Clinical practice for the diagnosis of cardiac arrhythmias in patients on renal replacement therapy: data from a Lombard survey]

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.

Effect of VDRA on survival in incident hemodialysis patients: results of the FARO-2 observational study

BACKGROUND

Mortality rate among patients with stage five chronic kidney disease (CKD) maintained on hemodialysis (HD) is high. Although evidence suggests that use of Vitamin D Receptor Activators (VDRA) in CKD patients increases survival, few studies have examined the effect of VDRA in incident HD patients. The FARO-2 study evaluated the clinical outcome of VDRA therapy on mortality in incident HD patients.

METHODS

FARO-2 was a longitudinal epidemiological study performed on 568 incident HD patients followed prospectively from 26 dialysis centers over a 3-year period. Data were collected every 6 months using a questionnaire, obtaining clinical, biochemical and therapeutic parameters. Kaplan-Meier curves and Cox proportional hazard regression models were used to determine cumulative probability of time-to-death and adjusted hazard ratios.

RESULTS

568 patients (68% male) with an average age of 65.5 years were followed up. Mean dialysis duration at study entry was 3 months. VDRA use increased from 46% at 6 months to 54.7% at 36 months of follow-up (p = 0.08). No difference was observed in the presence of comorbid diseases at baseline in patients with and without VDRA therapy. Cumulative probability of survival at 24 months was 74.5% (95% CI: 70.2-78.3). Patients receiving VDRA therapy showed a significant increase in survival at 24 months (80.7%; 95% CI: 75.7-84.8) compared to those without (63.3%; 95% CI: 54.8-70.7, p <0.01). The presence of vascular disease, decreased hemoglobin, increased P and lack of VDRA treatment were significantly associated with an increased risk of mortality. Lack of VDRA treatment still remained significant as a predictor of mortality after adjusting for levels of PTH, P and Ca (HR = 2.16, 95% CI: 1.09-4.30, p = 0.03).

CONCLUSIONS

Findings from FARO-2 indicate that in incident HD patients VDRA therapy was associated with increased survival.

Management of mineral metabolism in hemodialysis patients: discrepancy between interventions and perceived causes of failure

BACKGROUND

Mineral and bone disorders (MBD) in patients undergoing hemodialysis (HD) are a major clinical complication. Current therapeutic strategies do not attain the expected results. The Italian audit on mineral metabolism was implemented to investigate MBD management through a "patient-oriented" approach.

METHODS

Clinical and laboratory data pertinent to MBD from 509 prevalent adult patients on chronic HD were recorded and examined (audit), after which individual strategies were elaborated to improve MBD control. Their effectiveness was evaluated 6 months after the audit (Post-6).

RESULTS

The audit disclosed poor MBD control in a high percentage of patients (56 %). Low compliance to treatment was the major determinant of failure (in 43.5 % of cases). Logistic regression showed a direct correlation between high degree of compliance and the achievement of therapeutic targets, e.g. parathyroid hormone: odds ratio (OR) 2.48, p = 0.015. In contrast, a minority of the proposed interventions (14.7 %) included strategies to improve patient compliance. At Post-6, despite a significant increase in drug prescription (p < 0.05 vs. audit), the rate of successful MBD control was unchanged.

CONCLUSIONS

Low compliance with treatment is a major, but still neglected, cause of failure in the achievement of MBD control in HD patients.

Homoarginine and mortality in pre-dialysis chronic kidney disease (CKD) patients

Background and Aims

Homoarginine, a precursor of nitric oxide, is an inverse predictor of death in dialysis patients and in subjects with cardiovascular disease and normal kidney function but its relationship with clinical outcomes in chronic kidney disease (CKD) patients not yet on dialysis is unknown.

Design, setting, participants and measurements

We enrolled 168 consecutive predialysis CKD patients (Age: 70±11 yrs; 26% Diabetics; eGFR 34±18 ml/min/1.73 m²) referred to a tertiary care centre and measured laboratory data on kidney function and cardiovascular risk factors. We modeled progression to dialysis or death as a function of homoarginine, using Cox’s regression, accounting for clinical characteristics, baseline levels of kidney function, and markers of inflammation.

Results

On crude and adjusted analyses homoarginine was directly associated with the eGFR and patients with more compromised renal function exhibited lower homoarginine levels. Furthermore homoarginine was also independently related to L-arginine, serum albumin and body mass index, and inversely related to proteinuria, C-reactive protein and age. During the study (follow up median time 4 years, inter-quartile range 1.7 to 7.0 years) 56 patients started dialysis and 103 died and homoarginine was a strong inverse predictor of the incidence rate of both outcomes (P = 0.002 and P = 0.017).

Conclusions

Homoarginine declines with advancing renal disease and is inversely related to progression to dialysis and mortality. The nature of the link between homoarginine and clinical outcomes is amenable to testing in clinical trials.

What can we learn from a statistically inconclusive trial? Consensus conference on the EVOLVE study results

The link between serum parathyroid hormone (iPTH) and cardiovascular (CVS) mortality has not been fully elucidated. The EVOLVE Study was designed to test whether a drug such as cinacalcet, aimed at lowering iPTH, could reduce the astonishingly high cardiovascular risk in patients on maintenance dialysis (CKD-5D). Accordingly, the primary outcome of the study was the combined endpoint of time to death or hospitalization due to CVS factors or from any cause. Time to bone fracture and parathyroidectomy were regarded as secondary endpoints. At study completion, the Intention-To-Treat analysis documented a non- significant 7% (Hazard Ratio: 0.93; 95% Confidence interval: 0.85-1.02; P = 0.11) reduction of the primary composite endpoint. However, the intention to treat analysis does not take into account adherence to drug regimens or control for factors that may potentially jeopardize the conduction of the study. In particular, in spite of a careful pre-planned study sample calculation, the final power of the EVOLVE study was 54% instead of the assumed 90%, greatly reducing the reliability of study results. Furthermore, the pre-planned multivariable adjustment of the primary endpoint suggests a nominally significant reduction of the risk of the primary composite endpoint when age is entered into the statistical model. The sensitivity analysis further corroborates this result. The Lag Time Censoring Analysis (LTCA) evidenced a nominally significant 15% risk reduction of the composite endpoint among patients allocated to cinacalcet if the patients follow-up was terminated 6 months after the study drug discontinuation, as pre-planned in the protocol. It is interesting that the LTCA suggests that the effect of cinacalcet weakened over time and became insignificant after about 1 year from drug discontinuation. Although authors could not detect any effect of cinacalcet on bone fracture associated with cinacalcet use, the secondary analyses of the EVOLVE trial suggest a nominally significant 60-70% risk reduction of parathyroidectomy and a reassuring safety profile of prolonged exposure to cinacalcet. In summary, the EVOLVE study adds to the list of inconclusive randomized clinical trials in Nephrology. However, the preplanned exploratory and sensitivity analyses suggest that when imbalances of patients characteristics at study entry (i.e. age) or study drug discontinuation are considered, a 'nominally' significant risk reduction in CVS and parathyroidectomy associated with cinacalcet treatment is noted.

Serum phosphorus reduction in dialysis patients treated with cinacalcet for secondary hyperparathyroidism results mainly from parathyroid hormone reduction

Background

The calcimimetic cinacalcet lowers parathyroid hormone (PTH), calcium (Ca) and phosphorus (P) in dialysis patients with secondary hyperparathyroidism (SHPT). We explored serum P changes in dialysis patients treated with cinacalcet, while controlling for vitamin D sterol and phosphate binder (PB) changes, based on data from the pan-European observational study ECHO.

Methods

Patients were categorized by serum P change (decreased/unchanged/increased) at 12 months after starting cinacalcet and subcategorized by vitamin D sterol and PB dose changes (decreased/unchanged/increased). The impact of PTH, Ca and P, and vitamin D sterol, PB and cinacalcet doses (absolute values and/or change) was evaluated. Predictors of P change were explored using univariate and multivariate general linear models (GLM) and logistic regression analysis.

Results

At Month 12, 661 (41%) of 1607 patients had decreased, 61 (4%) unchanged and 400 (25%) increased serum P, while 485 patients had missing data. In 45% of the patients with serum P reduction, vitamin D was either increased or unchanged and P binders decreased or unchanged. PTH was a key predictor of serum P reduction, with an estimated 3% decrease in P per 10% reduction in PTH. Changes in vitamin D sterol and PB doses were not generally significant factors in GLM and regression analyses.

Conclusions

The serum P reduction observed in a significant proportion of dialysis patients after adding cinacalcet to an existing therapeutic regimen for SHPT appears to result mainly from PTH reduction, rather than from changes in vitamin D sterol or PB doses. Financial support for the ECHO study was provided by Amgen.

[Prevention of cardiovascular comorbidities in uremic patients on chronic dialysis: metabolic derangements and cardiovascular risk]

Cardiovascular events are the main cause of morbidity and mortality in uremic patients on renal replacement therapy. Traditional cardiovascular risk factors such as dyslipidemia and hypertension as well as risk factors specific to uremia such as calcium and phosphate metabolism derangements are involved in the development and progression of the cardiovascular alterations. In this review the results of prospective randomized trials that evaluated the effects on cardiovascular morbidity and mortality of lowering serum cholesterol and phosphate levels and controlling secondary hyperparathyroidism are critically reexamined. A recent trial of 9270 patients with chronic kidney disease documented a significant reduction of major atherosclerotic events by lowering LDL cholesterol by 39 mg/dL on average with sinvastatin plus ezetimibe over nearly 5 years. No significant reduction in mortality rate was documented by lowering serum phosphate levels with sevelamer rather than calcium-containing phosphate binders. Treatment of secondary hyperparathyroidism with cinacalcet plus lowdose vitamin D seems to attenuate the progression of vascular calcification.

Optimizing the dialysate calcium concentration in bicarbonate haemodialysis

BACKGROUND

There is no consensus regarding the optimal dialysate calcium concentration (DCa) during haemodialysis (HD). Low DCa may predispose to acute arrhythmias, whereas high DCa increases the long-term risk of soft tissue calcifications.

METHODS

Twenty-two HD patients treated in four dialysis centres underwent two HD sessions, respectively, with 1.5 and 1.25 mmol/L total DCa. Calcium mass balance (CMB) was calculated from ionized calcium (iCa) in the dialysate and blood at the start and end of each run, using a kinetic formula to define the mean concentrations in the blood and dialysate and then estimating CMBs over the entire treatments.

RESULTS

Mean blood iCa levels increased using 1.5 DCa, whereas they remained unchanged using 1.25 DCa. Diffusive CMB positively correlated with the dialysate/blood iCa gradient. With 1.5 DCa, diffusive CMBs were strongly positive at the blood side and negative at the dialysate side, indicating transfer from dialysate to blood. With 1.25 DCa, despite a negative dialysate/blood iCa gradient, diffusive CMB was slightly positive in blood and negative in dialysate. The global balances based on both the convective and diffusive components showed a positive net transfer of Ca from dialysate to blood with 1.5 DCa and an approximately neutral Ca flux with 1.25 DCa.

CONCLUSIONS

While CMB is nearly neutral when using 1.25 DCa, the use of 1.5 DCa results in a gain of Ca during HD. The risks associated with Ca load should be considered in the choice of DCa prescription for HD but need also be weighed against the risk of worse haemodynamic dialysis tolerance.

[Use of cinacalcet in clinical practice for the treatment of secondary hyperparathyroidism: analysis of the Italian data of the ECHO study]

Several studies have shown that, compared with standard therapy, cinacalcet reduces parathyroid hormone (PTH) as well as calcium and phosphorus levels in dialysis patients with secondary hyperparathyroidism (SHPT). The ECHO study evaluated cinacalcet use in actual clinical practice. ECHO enrolled 1865 patients treated with cinacalcet at 187 sites in 12 European countries. In Italy 263 patients were enrolled at 20 sites. The primary objective of the study was to evaluate K/DOQI target achievement in SHPT dialysis patients after the introduction of cinacalcet. Patients on cinacalcet treatment between July 2005 and October 2006 were enrolled and data were collected from 6 months prior to starting cinacalcet up to 12 months after. No treatment algorithm was provided to the investigators. Italian patients had suboptimally controlled SHPT at baseline according to K/DOQI targets (median PTH 760 pg/mL, P 5.4 mg/dL, Ca 9.7 mg/dL). After 1 year of cinacalcet treatment a reduction of PTH (-53.4%), Ca (-7.3%), P (-4.6%) and Ca x P (-14.4%) was observed. The proportion of patients that reached the K/DOQI targets after 1 year of cinacalcet treatment was higher compared to baseline for all parameters (PTH 32% vs 5%; Ca 48% vs 35%; P 59% vs 55%, Ca x P 82% vs 64%). The Italian ECHO data show that cinacalcet treatment increases the proportion of patients achieving the K/DOQI targets for PTH, Ca, P and Ca x P, confirming the effectiveness of cinacalcet in clinical practice in Italy. These findings are consistent with the phase III study results on cinacalcet use in dialysis patients in Europe.

[Management of hyperphosphatemia in dialysis patients: the role of phosphate binders]

Hyperphosphatemia is a characteristic feature of chronic kidney disease-mineral and bone disorder (CKD-MBD). Phosphorus excess is an independent risk factor for cardiovascular morbidity and mortality in patients with advanced CKD. The keystones of hyperphosphatemia treatment are reduction of dietary phosphorus, use of phosphate binders, and optimized phosphorus removal via dialysis. Several phosphate binders have been approved for use; all share a common functionality in that they bind phosphorus and reduce the amount absorbed in the gastrointestinal lumen. In the past, treatment with oral phosphate binders was intended to prevent symptomatic secondary hyperparathyroidism. More recently, achieving tighter control of markers associated with abnormal mineral metabolism has become a specific therapeutic objective. This therapeutic shift has been driven by several factors: observational data that link disordered mineral metabolism with adverse clinical outcomes; concern about vascular calcification, which is also associated with adverse outcomes and may correlate with exposure to calcium-based phosphatebinding agents; and, perhaps, the availability of new therapeutic agents. In this article we review the rationale for treatment with oral phosphate binders, discuss evidence that supports the use of the available agents, and suggest an approach for clinical practice.

Modeling survival of arteriovenous accesses for hemodialysis: semiparametric versus parametric methods

BACKGROUND AND OBJECTIVES

Comparing outcomes of arteriovenous grafts and fistulas is challenging because the pathophysiology of access dysfunction and failure rate profiles differ by access type. Studying how risks vary over time may be important.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Longitudinal data from 535 incident hemodialysis patients were used to study the relationship between access type and access survival, without (semiparametric Cox modeling) and with specification of the underlying hazard function (parametric Weibull modeling).

RESULTS

The hazard for failure of fistulas and grafts declined over time, becoming proportional only after 3 months from surgery, with a graft versus fistula hazard ratio of 3.2 (95% confidence interval 1.9 to 5.3; Cox and Weibull estimation) and time ratio of 0.11 (i.e., the estimated access survival time was approximately one tenth shorter in grafts; 95% confidence interval 0.04 to 0.28; Weibull estimation only). Considering the entire observation period, grafts had slower hazard decline (P<0.001) with shorter median survival times than fistulas (8.4 versus 38.3 months; Weibull regression only).

CONCLUSIONS

Parametric models of arteriovenous access survival may provide relevant information about temporal risk profiles and predicted survival times.

[Non-pharmacological calcium metabolism control in patients undergoing hemodialysis]

Calcium overload has been claimed to be involved in the increased vascular morbidity and mortality of dialysis patients. Conversely, calcium depletion can worsen secondary hyperparathyroidism and reduce bone mass. When residual renal function is null or negligible, the calcium balance is mainly determined by the calcium absorbed from the intestine, and that gained or lost from or into the dialysate. This article aims to review the assessment and mechanisms of calcium flux during hemodialysis (HD) and hemodiafiltration (HDF). Calcium mass transfer in HD is mainly dependent on the ionized calcium concentration gradient between dialysate and blood, ultrafiltration volume (Qf) and treatment time. Calcium flux in HDF is also affected by the infusion mode. In post-dilution HDF, the calcium balance is comparable to that in HD for a given concentration gradient between dialysate and blood. Conversely, in pre-dilution HDF the dialysate calcium concentration should be increased by about 0.25 mmol/L to maintain comparable balances. For a given dialysate total calcium concentration, the ionized fraction changes according to the pH and the bicarbonate concentration of the solution. Thus, the dialysate ionized calcium is higher (94% of total calcium) in acetate-free biofiltration (AFB, a HDF modality where the dialysate does not contain bicarbonate or acetate) than in standard HDF (dialysate bicarbonate and acetate concentration of 31 mmol/L and 5 mmol/L, respectively), where the dialysate ionized calcium fraction is about 84% of the total calcium. As a consequence, calcium mass transfer is more positive in AFB compared to post-dilution HDF at similar dialysate total calcium concentrations. Clinical studies and kinetic models have shown that the calcium mass transfer during HD is neutral when the ionized calcium gradient and Qf are zero. This suggests that patients dialysed against a dialysate total calcium concentration of 1.25 mmol/L (corresponding to ionized calcium of 1.25 x 0.84 = 1.05 mmol/L) should have a serum ionized calcium concentration of 1.05 mmol/L and no weight loss to achieve a neutral calcium flux during HD treatment. In patients with serum ionized calcium in the normal range and an average Qf of 2-3 L, calcium losses of about 5-12 mmol (200-480 mg) have been documented during a single HD treatment with a dialysate calcium concentration of 1.25 mmol/L. Such losses might counterbalace the calcium gained by intestinal absorption (about 4-5 mmol/day or 160-200 mg/day in patients with an oral daily calcium intake of 1-1.5 g and normal vitamin D status) and ensure an overall approximately neutral calcium balance. The development and validation of kinetic models able to prescribe the dialysate calcium concentration necessary to achieve a neutral calcium balance in relation to dialysis treatment time, Qf, serum ionized calcium concentration, oral calcium intake, and vitamin D therapy is desirable.

Interaction between parathyroid hormone and the Charlson comorbidity index on survival of incident haemodialysis patients

BACKGROUND

Haemodialysis patients are ageing and have with a high rate of comorbidities. The impact of this novel clinical setting on intact parathyroid hormone (iPTH) is not well established.

METHODS

For this observational, prospective multicentre cohort study, incident haemodialysis patients were recruited in 40 Italian centres and followed up for a mean period of 18 +/- 6.7 months. Clinical characteristics and biochemistry were recorded at baseline. Comorbid conditions were scored by the Charlson comorbidity index (CCI).

RESULTS

Data of 411 patients (mean age: 66.5 +/- 14.8 years; 17.3% >80 years old) were recorded. The mean CCI was 4.17 +/- 2.8. In patients with CCI >0, an inverse correlation was observed between CCI (excluding age) and iPTH (P = 0.00002). Independently of CCI, patients with iPTH <150 pg/ml had 76% as high as the risk of all-cause mortality. After multivariable adjustment, the combination of the first tertile of iPTH with second and third tertiles of CCI was significantly associated with all-cause mortality (RR = 3.83, P = 0.02; RR = 3.79, P = 0.01, respectively).

CONCLUSIONS

Incident haemodialysis patients suffer from a high rate of clinical complications. In these patients, low iPTH and high CCI are often associated and very likely responsible for an adverse outcome.