The Uricosuric Effect of SGLT2 Inhibitors Is Maintained in the Long Term in Patients with Chronic Kidney Disease and Type 2 Diabetes Mellitus

(1) Background: Sodium-glucose co-transporter 2 inhibitors (SGLT2is) increase uric acid excretion. The intensity of uricosuria is linked to glycosuria. (2) Methods: We aim to analyze the effect of SGLT2 inhibitors on urinary fractional excretion (FE) of uric acid and glucose in patients with type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD) in a single-center retrospective study with patients with T2DM and CKD who started on treatment with SGLT2is. Patients on renal replacement therapy or with glucagon-like peptide-1 (GLP1) analogs were excluded. Subgroup analysis was performed according to the estimated glomerular filtration rate (eGFR), the SGLT2i molecule, the main comorbidities, and concomitant treatment. As a secondary objective, the study analyzed the effect of SGLT2 inhibitors on uricemia levels. (3) Results: Seventy-three patients were analyzed, with a mean follow-up of 1.2 years. Uric acid and glucose FE significantly increased after the initiation of SGLT2is. This increase remained stable during the follow-up without differences among eGFR groups. No significant reduction in uricemia was observed. However, a trend towards a decrease was observed. (4) Conclusion: The use of SGLT2is in patients with CKD and T2DM is associated with an increase in uric acid FE, which maintains stability irrespective of glomerular filtration loss at least during 24 months of follow-up.

Standardizing health outcomes for chronic kidney disease. Adaptation of the international consortium for health outcomes measurement standard set to the Spanish setting

BACKGROUND AND OBJECTIVES

We aim to adapt the International Consortium for Health Outcomes Measurements standard set for chronic kidney disease (CKD) patients to the Spanish setting and supplement it with those variables agreed upon through initiatives proposed by the Spanish Society of Nephrologists (S.E.N.).

MATERIAL AND METHODS

The working group defined a first standard set of variables based on a literature review. The S.E.N. members then assessed the suitability of each variable for inclusion (Consensus≥75%). A second draft of the standard set was generated and evaluated by the Patient advocacy group Federación Nacional de Asociaciones para la Lucha Contra las Enfermedades del Riñón (ALCER). Lastly, the working group established the final standard set of variables (Consensus≥75%).

RESULTS

The standard set targets patients with very high-risk CKD (G3a/A3 and G3b/A2-G5) in pre-end-stage kidney disease (pre-ESKD), hemodialysis (HD), peritoneal dialysis (PD), kidney transplantation (KT) or conservative care (CC). The essential follow-up variables agreed for all patients (All) were patient survival, hospitalizations, cardiovascular events, smoking status, health-related quality of life, pain, fatigue, physical function, daily activities, depression, renal function and hemoglobin. Additionally, it was agreed to collect PD survival (in PD patients), peritonitis (PD), infection/bacteremia (PD, HD, KT), vascular access type (HD), vascular access survival (HD), acute rejection (KT), post-transplant cancer (KT), albuminuria (KT) and kidney allograft survival (KT). The optional variables agreed were phosphorus (All), potassium (All), diabetes control (All with diabetes), and albuminuria (pre-ESKD).

CONCLUSIONS

This standard set may constitute a highly efficient tool allowing the evaluation of patient outcomes and helping to define strategies to enhance CKD patients' quality of care in the Spanish healthcare system.

The Immunobiogram, a novel in vitro diagnostic test to measure the pharmacodynamic response to immunosuppressive therapy in kidney transplant patients

BACKGROUND

Diagnostic tools to measure the response to individual immunosuppressive drugs for transplant patients are currently lacking. We previously developed the blood-based Immunobiogram bioassay for in-vitro characterization of the pharmacodynamic response of patients' own immune cells to a range of immunosuppressants. We used Immunobiogram to examine the association between patients' sensitivity to their prescribed immunosuppressants and clinical outcome.

METHODS

We conducted an international, multicenter, observational study in a kidney transplant population undergoing maintenance immunosuppressive therapy. Patients were selected by clinical course poor [PCC] N = 53 (with renal dysfunction, and rejection signs in biopsy or/and an increase in DSA strength in last 12 months) versus good [GCC] N = 50 (with stable renal function and treatment, no rejection and no DSA titers). Immunobiogram dose-response curve parameters were compared between both subgroups in patients treated with mycophenolate, tacrolimus, corticosteroids, cyclosporine A or everolimus. Parameters for which significant inter-group differences were observed were further analyzed by univariate and subsequent multivariate logistic regression.

RESULTS

Clinical outcome was associated with following parameters: area over the curve (AOC) and 25% (ID25) and 50% (ID50) inhibitory response in mycophenolate, tacrolimus, and corticosteroid-treated subgroups, respectively. These statistically significant associations persisted in mycophenolate (OR 0.003, CI95% <0.001-0.258; p = 0.01) and tacrolimus (OR < 0.0001, CI95% <0.00001-0.202; p = 0.016) subgroups after adjusting for concomitant corticosteroid treatment, and in corticosteroid subgroup after adjusting for concomitant mycophenolate or tacrolimus treatment (OR 0.003; CI95% <0.0001-0.499; p = 0.026).

CONCLUSIONS

Our results highlight the potential of Immunobiogram as a tool to test the pharmacodynamic response to individual immunosuppressive drugs.

Transitions in an integrated model of renal replacement therapy in a regional health system

INTRODUCTION AND OBJECTIVES

The choice of renal replacement therapy (RRT) is an important decision that determines the quality of life and survival. Most patients change from one RRT modality to another to adapt RRT to clinical and psychosocial needs. This has been called «integrated model of RRT» that implies new questions about the best sequence of techniques.

MATERIAL AND METHODS

The study describes the impact of transitions between RRT modalities on survival using the Madrid Registry of Renal Patients (2008-2018). This study used the proportional hazards models and competitive risk models to perform an intention-to-treat (ITT), according to their 1st RRT modality and as-treated (AT) analysis, that consider also their 1st transition.

RESULTS

A total of 8971 patients started RRT during this period in Madrid (6.6 Million population): 7207 (80.3%) on hemodialysis (HD), 1401 (15.6%) on peritoneal dialysis (PD) and 363 (4.2%) received a pre-emptive kidney transplantation (KT). Incident HD-patients were older (HD group 65.3 years (SD 15.3) vs PD group 58.1 years (SD 14.8) vs KTX group 52 years (SD 17.2); p < 0.001) and had more comorbidities. They presented higher mortality (HD group 40.9% vs PD group 22.8% vs KTX group 8.3%, p < 0.001) and less access to a transplant (HD group 30.4% vs PD group 51.6%; p < 0.001). Transitions between dialysis techniques define different groups of patients with different clinical outcomes. Those who change from HD to PD do it earlier (HD → PD: 0.7 years (SD 1.1) vs PD → HD: 1.5 years (SD 1.4) p < 0.001), are younger (HD → PD: 53.5 years (SD 16.7) vs PD → HD: 61.6 years (SD 14.6); p < 0.001), presented less mortality (HD → PD: 24.5% vs PD → HD: 32.0%; p < 0.001) and higher access to a transplant (HD → PD: 49.4% vs PD → HD: 31.7%; p < 0.001). Survival analysis by competitive risks is essential for integrated RRT models, especially in groups such as PD patients, where 51.6% of the patients were considered as lost follow-up (received a KTX after during the first 2.5 years on PD). In this analysis, survival of patients who change from one technique to another, is more similar to the destination modality than the origin one.

CONCLUSION

Our data suggest that transitions between RRT-techniques describes different patients, who associate different risks, and could be analyzed in an integrated manner to define improvement actions. This approach should be incorporated into the analysis and reports of renal registries.

Effect of Expanded Hemodialysis with Theranova® in Patients with COVID-19

INTRODUCTION

Cytokine storm control is the main target for improving severe COVID-19 by using immunosuppressive treatment. Effective renal replacement therapy (RRT) could give us an advantage removing cytokines in patients with RRT requirements superimposed on COVID-19.

METHODS

This is a prospective observational study in COVID-19 patients who required hemodialysis (HD). Patients were assigned to online hemodiafiltration (OL-HDF) and expanded HD (HDx) according to Brescia group recommendations. We measured several cytokines, β2 microglobulin and albumin levels pre/post-dialysis and on 1st-2nd week. We compared levels among both techniques and control group (HD without COVID-19).

RESULTS

We included 26 patients: 18 with COVID-19 on RRT (5 of them had acute kidney injury [AKI]) and 8 controls. We confirm higher cytokine levels in COVID-19 patients than controls and even higher in patients with AKI than in those with chronic kidney disease. Most cytokines raised during HD session, except IL-10 and TNFα. IL-10 was eliminated by any dialysis technique, while clearance of TNFα was higher in the HDx group. HDx achieved a deeper normalization of cytokines and β2 microglobulin reduction. Mortality was higher in the OL-HDF group than the HDx group.

DISCUSSION

Not all cytokines behave equally along HD session. The following characteristics should be taken into account, such as intrinsic kinetic profile during a HD session. HDx seems to get better performance, probably due to the combination of different factors; however, we did not reach statistical significance due to the small sample size, dropout, and reduction of AKI incidence during the 2nd pandemic wave.

CONCLUSION

HDx appears to provide better clearance for TNFα and β2 microglobulin during HD session and associates lower mortality. We propose the HDx technique for COVID-19 patients with RRT requirements since it seems to be safe and more effective than OL-HDF. Further studies are still needed, but we hope that our preliminary data may help us in future pandemic waves of SARS-CoV-2 or other viruses still to come.

Corticosteroids and mycophenolic acid analogs in IgA nephropathy with progressive decline in kidney function

Background

A randomized controlled trial (RCT) demonstrated a beneficial effect of corticosteroids (CS) plus cyclophosphamide followed by azathioprine in progressive IgA nephropathy (IgAN). Although treatment with CS and mycophenolic acid analogs (MPAA) remains controversial in IgAN, there is no information about their effect in progressive IgAN.

Methods

Patients with progressive IgAN, defined by a decrease in estimated glomerular filtration rate (eGFR) of at least 10 ml/min/1.73 m2 in the 12 months prior to the start of treatment, proteinuria ≥ 0.75 g/24h despite maximum tolerated doses of renin-angiotensin system blockers (RASB) and persistent hematuria, who had received treatment with CS+MPAA were included in this retrospective study. The main outcome was the difference between the eGFR slope from the start of treatment with CS+MPAA to the last visit with this treatment with respect to the eGFR slope during the 12 months prior to start of treatment.

Results

Twenty-five patients were included in the study. Mean duration of CS+MPAA treatment was 24.7±15.2 months. In the 12 months prior to treatment the median rate of kidney function decline was -23 [-32 to -16] ml/min/1.73 m2 per year. After the onset of treatment, the median eGFR slope was +5 [+3 to +9] ml/min/1.73 m2 per year (P = 0.001 with respect to the 12 months prior to treatment). Proteinuria decreased from 1.8 (1.0-2.5) g/day at baseline to 0.6 (0.3-1.2) g/day at the end of treatment (P = 0.01) and hematuria disappeared in 40% of the patients. There were no serious adverse effects requiring treatment discontinuation.

Conclusions

CS + MPAA is an effective treatment in IgAN patients with a sustained decline in kidney function accompanied by persistent proteinuria and hematuria despite optimized conservative treatment. Prospective studies are needed to confirm these results.

Transitions in an integrated model of renal replacement therapy in a regional health system

INTRODUCTION AND OBJECTIVES

The choice of renal replacement therapy (RRT) is an important decision that determines the quality of life and survival. Most patients change from one RRT modality to another to adapt RRT to clinical and psychosocial needs. This has been called «integrated model of RRT» that implies new questions about the best sequence of techniques.

MATERIAL AND METHODS

The study describes the impact of transitions between RRT modalities on survival using the Madrid Registry of Renal Patients (2008-2018). This study used the proportional hazards models and competitive risk models to perform an intention-to-treat (ITT), according to their 1st RRT modality and as-treated (AT) analysis, that consider also their 1st transition.

RESULTS

A total of 8971 patients started RRT during this period in Madrid (6.6 Million population): 7207 (80.3%) on hemodialysis (HD), 1401 (15.6%) on peritoneal dialysis (PD) and 363 (4.2%) received a pre-emptive kidney transplantation (KTX). Incident HD-patients were older (HD group 65.3 years (SD 15.3) vs PD group 58.1 years (SD 14.8) vs KTX group 52 years (SD 17.2); p<0.001) and had more comorbidities. They presented higher mortality (HD group 40.9% vs PD group 22.8% vs 8.3% KTX group, p<0.001) and less access to a transplant (HD group 30.4% vs DP group 51.6%; p<0.001). Transitions between dialysis techniques define different groups of patients with different clinical outcomes. Those who change from HD to PD do it earlier (HD→PD: 0.7 years (SD 1.1) vs PD→HD: 1.5 years (SD 1.4) p<0.001), are younger (HD→PD: 53.5 years (SD 16.7) vs PD→HD: 61.6 years (SD 14.6); p<0.001), presented less mortality (HD→PD: 24.5% vs PD→HD: 32.0%; p<0.001) and higher access to a transplant (HD→PD: 49.4% vs PD→HD: 31.7%; p<0.001). Survival analysis by competitive risks is essential for integrated RRT models, especially in groups such as PD patients, where 51.6% of the patients were considered as lost follow-up (received a KTX after during the first 2.5 years on PD). In this analysis, survival of patients who change from one technique to another, is more similar to the destination modality than the origin one.

CONCLUSION

Our data suggest that transitions between RRT-techniques describes different patients, who associate different risks, and could be analyzed in an integrated manner to define improvement actions. This approach should be incorporated into the analysis and reports of renal registries.

Is peritoneal dialysis suitable technique CKD patients over 65 years? A prospective multicenter study

BACKGROUND

Chronic kidney disease (CKD) is increasing in patients older than 65 years and is related to morbidity, frailty, and dependence. Peritoneal dialysis (PD) has classically been associated with young patients with an active life.

HYPOTHESIS

PD should be offered to patients over 65 years. We search for any unfavorable results that may advice not to recommend PD therapy for this group.

OBJECTIVE

To describe PD treatment and outcomes in patients > 65 years, to compare their results with patients < 65 years and to identify areas with room for improvement in a real-life study.

STUDY

Prospective, observational, and multicenter study performed in incident PD patients, from January 2003 until January 2018.

RESULTS

We included 2,435 PD patients, 31.9% were older than 65 years; there was a difference of 25 years between both groups. Median follow up was 2.1 years. Older than 65 years group had more comorbidity: Diabetes (29.5% vs 17.2%; p < 0.001), previous CV events 34.5% vs 14.0%; p < 0.001), Charlson index (3.8 vs 3.0; p < 0.001). We did not find differences in efficacy and PD adequacy objectives fulfillment, anaemia management or blood pressure during follow-up. Peritonitis rate was higher in older 65 years group (0.65 vs 0.45 episodes/patient/year; p < 0.001), but there was not differences in germs, admission rate and follow up. Mortality was higher in older 65 years group (28.4% vs 9.4%) as expected. PD permanence probability was similar (2.1 years). The main cause of PD withdrawal was transplant in group < 65 years (48.3%) and transfer to HD in group > 65 years. The main reason was caregiver or patient fatigue (20.2%), and not technique failure (7.3%). Multivariate Cox regression analysis showed a relation (HR [95%CI]) between mortality and age > 65 years 2.4 [1.9-3.0]; DM 1.6 [1.3-2.1]; CV events 2.1 [1.7-2.7]. Multivariate Cox regression analysis identify a relation between technique failure and age > 65 years 1.5 [1.3-1.9]; DM 1.6 [1.3-1.9] and previous transplant 1.5 [1.2-2.0].

CONCLUSION

Patients older than 65 years fulfilled PD adequacy criteria during the follow up. We believe PD is a valid option for patients older 65 years. It is necessary to try to prevent infections and patient/caregiver fatigue, to avoid HD transfer for reasons not related to technique failure.

Anemia in Chronic Kidney Disease: From Pathophysiology and Current Treatments, to Future Agents

Anemia is a common complication in chronic kidney disease (CKD), and is associated with a reduced quality of life, and an increased morbidity and mortality. The mechanisms involved in anemia associated to CKD are diverse and complex. They include a decrease in endogenous erythropoietin (EPO) production, absolute and/or functional iron deficiency, and inflammation with increased hepcidin levels, among others. Patients are most commonly managed with oral or intravenous iron supplements and with erythropoiesis stimulating agents (ESA). However, these treatments have associated risks, and sometimes are insufficiently effective. Nonetheless, in the last years, there have been some remarkable advances in the treatment of CKD-related anemia, which have raised great expectations. On the one hand, a novel family of drugs has been developed: the hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs). These agents induce, among other effects, an increase in the production of endogenous EPO, improve iron availability and reduce hepcidin levels. Some of them have already received marketing authorization. On the other hand, recent clinical trials have elucidated important aspects of iron supplementation, which may change the treatment targets in the future. This article reviews the current knowledge of the pathophysiology CKD-related anemia, current and future therapies, the trends in patient management and the unmet goals.

Renal replacement therapy in critically ill patients with acute kidney injury: 2020 nephrologist's perspective

Renal replacement therapies (RRT) as support for acute kidney injury in critically ill patients have become a routine and essential practice in their management, resulting in the widespread use of various techniques among these patients, such as intermittent hemodialysis (IHD), extended hemodialysis and continuous RRT (CRRT). In this review we aim to summarize current evidence of indication, choice of modality, timing of initiation, dosing and technical aspects of RRT. We carried out a narrative review based on guidelines, consensus documents by main working groups and the latest relevant clinical trials on RRT in the critically ill. We did not find enough evidence of any RRT modality having superior benefits in terms of patient survival, length of intensive care unit/hospital stay or renal outcomes among critically ill patients, in spite of optimization of clinical indication, modality, timing of initiation and intensity of initial therapy. This is still a controverted matter, since only early start of high-flux CRRT has been proven beneficial over IHD among hemodynamically unstable postoperative patients. Our objective is to portrait current RRT practices in multidisciplinary management of critically ill patients by intensive care and nephrology professionals. Implication of a nephrologist in the assessment of hemodynamic status, coexisting medical conditions, renal outcome expectations and management of resources could potentially have benefits at the time of RRT selection and troubleshooting.

Is peritoneal dialysis suitable technique CKD patients over 65 years? A prospective multicenter study

BACKGROUND

Chronic kidney disease (CKD) is increasing in patients older than 65years and is related to morbidity, frailty, and dependence. Peritoneal dialysis (PD) has classically been associated with young patients with an active life.

HYPOTHESIS

PD should be offered to patients over 65years. We search for any unfavorable results that may advice not to recommend PD therapy for this group.

OBJECTIVE

To describe PD treatment and outcomes in patients >65years, to compare their results with patients <65years and to identify areas with room for improvement in a real-life study.

STUDY

Prospective, observational, and multicenter study performed in incident PD patients, from January 2003 until January 2018.

RESULTS

We included 2,435 PD patients, 31.9% were older than 65years; there was a difference of 25years between both groups. Median follow up was 2.1years. Older than 65years group had more comorbidity: Diabetes (29.5% vs 17.2%; p<0.001), previous CV events 34.5% vs 14.0%; p<0.001), Charlson index (3.8 vs 3.0; p<0.001). We did not find differences in efficacy and PD adequacy objectives fulfillment, anaemia management or blood pressure during follow-up. Peritonitis rate was higher in older 65years group (0.65 vs 0.45 episodes/patient/year; p<0.001), but there was not differences in germs, admission rate and follow up. Mortality was higher in older 65years group (28.4% vs 9.4%) as expected. PD permanence probability was similar (2.1years). The main cause of PD withdrawal was transplant in group <65years (48.3%) and transfer to HD in group >65years. The main reason was caregiver or patient fatigue (20.2%), and not technique failure (7.3%). Multivariate Cox regression analysis showed a relation (HR [95%CI]) between mortality and age>65years 2.4 [1.9-3.0]; DM 1.6 [1.3-2.1]; CV events 2.1 [1.7-2.7]. Multivariate Cox regression analysis identify a relation between technique failure and age>65years 1.5 [1.3-1.9]; DM 1.6 [1.3-1.9] and previous transplant 1.5 [1.2-2.0].

CONCLUSION

Patients older than 65years fulfilled PD adequacy criteria during the follow up. We believe PD is a valid option for patients older 65years. It is necessary to try to prevent infections and patient/caregiver fatigue, to avoid HD transfer for reasons not related to technique failure.

Acute kidney failure in patients admitted due to COVID-19

BACKGROUND AND AIM

In December 2019, a coronavirus 2019 (COVID-19) outbreak, caused by SARS-CoV-2, took place in Wuhan and was declared a global pandemic in March 2020 by the World Health Organization (WHO). It is a prominently respiratory infection, with potential cardiological, hematological, gastrointestinal and renal complications. Acute kidney injury (AKI) is found in 0.5%-25% of hospitalized COVID-19 patients and constitutes a negative prognostic factor. Renal damage mechanisms are not completely clear. We report the clinical evolution of hospitalized COVID-19 patients who presented with AKI requiring attention from the Nephrology team in a tertiary hospital in Madrid, Spain.

METHODS

This is an observational prospective study including all COVID-19 cases that required hospitalization and Nephrology management from March 6th to May 12th. We collected clinical and analytical data of baseline characteristics, COVID-19 and AKI evolutions.

RESULTS

We analyzed 41 patients with a mean age of 66.8 years (SD 2.1), 90.2% males, and with a history of chronic kidney disease (CKD) in 36.6%. 56.1% of patients presented with sever pneumonia or acute respiratory distress syndrome (ARDS), and 31.7% required intensive care. AKI etiology was prerenal in 61%, acute tubular necrosis in the context of sepsis in 24.4%, glomerular in 7.3% and tubular toxicity in 7.3% of the cases. We reported proteinuria in 88.9% and hematuria in 79.4% of patients. 48.8% of patients required renal replacement therapy (RRT). Median length of stay was 12 days (interquartilic range 9-23) and 22% of the population died. Patients who developed AKI during hospital stay presented with higher C-reactive protein, Lactate dehydrogenase-LDH and d-dimer values, more severe pulmonary damage, more frequent intensive care unit-ICU admission, treatment with lopinavir/ritonavir and biological drugs and RRT requirement.

CONCLUSIONS

Hypovolemia and dehydration are a frequent cause of AKI among COVID-19 patients. Those who develop AKI during hospitalization display worse prognostic factors in terms of pulmonary damage, renal damage, and analytical findings. We believe that monitorization of renal markers as well as individualized fluid management can play a key role in AKI prevention.

[Acute kidney failure in patients admitted due to COVID-19]

BACKGROUND AND AIM

In December 2019, a coronavirus 2019 (COVID-19) outbreak, caused by SARS-CoV-2, took place in Wuhan, China, and was declared a global pandemic in March 2020 by the World Health Organization. It is a prominently respiratory infection, with potential cardiological, hematological, gastrointestinal and renal complications. Acute kidney injury (AKI) is found in 0.5-25% of hospitalized COVID-19 patients and constitutes a negative prognostic factor. Renal damage mechanisms are not completely clear. We report the clinical evolution of hospitalized COVID-19 patients who presented with AKI requiring attention from the Nephrology team in a tertiary hospital in Madrid, Spain.

METHODS

This is an observational prospective study including all COVID-19 cases that required hospitalization and Nephrology management from March 6th to May 12th 2020. We collected clinical and analytical data of baseline characteristics, COVID-19 and AKI evolutions.

RESULTS

We analyzed 41 patients with a mean age of 66.8 years (SD 2.1), 90.2% males, and with a history of chronic kidney disease in 36.6%. A percentage of 56.1 presented with severe pneumonia or acute respiratory distress syndrome, and 31.7% required intensive care. AKI etiology was prerenal in 61%, acute tubular necrosis in the context of sepsis in 24.4%, glomerular in 7.3% and tubular toxicity in 7.3% of the cases. We reported proteinuria in 88.9% and hematuria in 79.4% of patients. A percentage of 48.8 required renal replacement therapy. Median length of stay was 12 days (IQR 9-23) and 22% of the population died. Patients who developed AKI during hospital stay presented with higher C-reactive protein, LDH and D-dimer values, more severe pulmonary damage, more frequent ICU admission, treatment with lopinavir/ritonavir and biological drugs and renal replacement therapy requirement.

CONCLUSIONS

Hypovolemia and dehydration are a frequent cause of AKI among COVID-19 patients. Those who develop AKI during hospitalization display worse prognostic factors in terms of pulmonary damage, renal damage, and analytical findings. We believe that monitorization of renal markers, as well as individualized fluid management, can play a key role in AKI prevention.

Renal replacement therapy in critically ill patients with acute kidney injury: 2020 nephrologist's perspective

Renal replacement therapies (RRT) as support for acute kidney injury in critically ill patients have become a routine and essential practice in their management, resulting in the widespread use of various techniques among these patients, such as intermittent hemodialysis (IHD), extended hemodialysis and continuous RRT (CRRT). In this review we aim to summarize current evidence of indication, choice of modality, timing of initiation, dosing and technical aspects of RRT. We carried out a narrative review based on guidelines, consensus documents by main working groups and the latest relevant clinical trials on RRT in the critically ill. We did not find enough evidence of any RRT modality having superior benefits in terms of patient survival, length of intensive care unit/hospital stay or renal outcomes among critically ill patients, in spite of optimization of clinical indication, modality, timing of initiation and intensity of initial therapy. This is still a controverted matter, since only early start of high-flux CRRT has been proven beneficial over IHD among hemodynamically unstable postoperative patients. Our objective is to portrait current RRT practices in multidisciplinary management of critically ill patients by intensive care and nephrology professionals. Implication of a nephrologist in the assessment of hemodynamic status, coexisting medical conditions, renal outcome expectations and management of resources could potentially have benefits at the time of RRT selection and troubleshooting.

Chronic kidney disease and acute kidney injury in the COVID-19 Spanish outbreak

BACKGROUND

Novel coronavirus disease 2019 (COVID-19) emerged in Wuhan and rapidly spread, affecting >10 million cases worldwide. Caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and primarily manifesting as an acute respiratory failure with interstitial and alveolar pneumonia, it can also affect multiple organs. Kidney involvement was underestimated in early reports and its role remains controversial. The aim of this study was to analyse the role of kidney damage in COVID-19 outcome.

METHODS

This is a prospective cohort study of 1603 consecutive patients admitted in a University Reference Hospital in the heart of the European outbreak.

RESULTS

Median age was 64 years, 40.4% were female, 15.2% presented diabetes mellitus, 35.7% hypertension and 20.3% obesity. On admission, the prevalence of elevated serum creatinine (sCr), proteinuria, leucocyturia and haematuria were 21.0, 37.8, 31.8 and 45.6%, respectively. In total, 43.5% of those with an elevated sCr had previous chronic kidney disease (CKD) and 11.4% of those with normal sCr developed an in-hospital acute kidney injury (AKI); 17 patients needed acute haemodialysis; and 197 patients died during hospitalization. Cox proportional hazard regression confirmed that elevated baseline sCr [hazard ratio (95% confidence interval) 2.40 (1.79-3.22)], previous CKD [1.59 (1.06-2.37)], haematuria [1 + 1.68 (0.92-3.06), 2-3 + 2.69 (1.49-4.87)] and in-hospital AKI [1.50 (0.92-2.44)] were independent risk factors for in-hospital death after adjusting for age, sex and comorbidity.

CONCLUSION

The prevalence of acute and chronic kidney disease on admission and in-hospital AKI is higher than previously reported in Wuhan, and is associated with high in-hospital mortality. We should increase our awareness towards kidney involvement and design specific strategies for management of COVID-19 in these patients.

Peritoneal Dialysis Can Be an Option for Dominant Polycystic Kidney Disease: an Observational Study

BACKGROUND

Autosomal dominant polycystic kidney disease (ADPKD) has been considered a relative contraindication for peritoneal dialysis (PD), although there are few specific studies available.

METHODS

A multicenter historical prospective matched-cohort study was conducted to describe the outcome of ADPKD patients who have chosen PD. All ADPKD patients starting PD (n = 106) between January 2003 and December 2010 and a control group (2 consecutive patients without ADPKD) were studied. Mortality, PD-technique failure, peritonitis, abdominal wall leaks and cyst infections were compared.

RESULTS

Patients with ADPKD had similar age but less comorbidity at PD inclusion: Charlson comorbidity index (CCI) 4.3 (standard deviation [SD] 1.6) vs 5.3 (SD 2.5) p < 0.001, diabetes mellitus 5.7% vs 29.2%, p < 0.001 and previous cardiovascular events 10.4% vs 27.8%, p < 0.001. No differences were observed in clinical events that required transient transfer to hemodialysis, nor in peritoneal leakage episodes or delivered dialysis dose. The cyst infection rate was low (0.09 episodes per patient-year) and cyst infections were not associated to peritonitis episodes. Overall technique survival was similar in both groups. Permanent transfer to hemodialysis because of surgery or peritoneal leakage was more frequent in ADPKD. More ADPKD patients were included in the transplant waiting list (69.8 vs 58%, p = 0.04) but mean time to transplantation was similar (2.08 [1.69 - 2.47] years). The mortality rate was lower (2.5 vs 7.6 deaths/100 patient-year, p = 0.02) and the median patient survival was longer in ADPKD patients (6.04 [5.39 - 6.69] vs 5.57 [4.95 - 6.18] years, p = 0.024).

CONCLUSION

Peritoneal dialysis is a suitable renal replacement therapy option for ADPKD patients.

[Cinacalcet in patients on peritoneal dialysis with moderate to severe hyperparathyroidism resistant to conventional treatment, a one-year, prospective study]

BACKGROUND

Cinacalcet has improved the management of hyperparathiroidism (HPTH) in hemodialysis. To our knowledge there are no specific studies on peritoneal dialysis (PD).

AIM

The aim of the present study was to evaluate the efficacy of Cinacalcet on the achievement of optimal and suboptimal targets on treatment of hyperparathiroidism (HPTH) in PD patients. As secondary objectives we have studied the safety of treatment and estimate the mean time to reach these targets, and evaluate economic cost.

METHODS

Eighteen patients undergoing more than 4 months on PD with a severe HPTH (PTH > 500 pg/ml) resistant to conventional treatment with diet, chelants and vitamin D were included in this prospective open-label study. We have used the targets of K/DOQITM-clinical guidelines as optimal target. We have selected as suboptimal targets: PTH < 350 pg/ml, phosphorus < 6 mg/dl and calcium < 10.4 mg/dl (only when simultaneous CaxP was under 55 mg2/dl2). Oral Cinacalcet was given with main meal in a single daily start dose of 30 mg and titrated thereafter monthly. We considered the first value on target as an event and used a Kaplan-Meyer survival analysis to estimate mean time to reach target.

RESULTS

On inclusion all patients have at least two previous PTH values over 500 pg/ml, PTH mean 695,3 (SD 96) and they were on PD with an appropriate efficacy during a mean of 15.56 months (SD 0.78). Mean follow-up time under Cinacalcet treatment was 12 months. The percentage of patients with a PTH under 350 pg/ml was 66,7% on month 3, 60% on month 6 and 100% after 1 year. The percentage of patients that reach an aggregate of all suboptimal targets (PTH< 350 pg/ml and calcium < 10.4 mg/dl and phosphorus< 6 mg/dl and CaxP < 55 mg2/dl2) was 33.3% on month 6 and 66.7% after 1 year. The mean time to reach PTH target was 2.33 months with a 95% confident interval [1.35-3.32] and to reach the aggregate of all target was 16.94 months [11.38-22.5]. Cinacalcet has been well tolerated, we reduced the dose in a single patient due to secondary effects, but treatment was not discontinued in any case.

CONCLUSION

In summary the addition of Cinacalcet to conventional treatment in PD patients with resistant HPTH has improved the achievement of targets, and has been reasonably safe in our patients.

Anemia management and treatment response in patients on hemodialysis: the MAR study

BACKGROUND

Anemia management guidelines describe the importance of anemia as a risk factor in hemodialysis and the need for clinical prospective studies focused on this role of anemia. Response to treatment with iron and epoetin is multifactorial, and results are still far from the targets set by the guidelines. The Morbidity and Mortality Anemia Renal study (MAR) is a multicenter prospective cohort study of hemodialysis (HD), designed to assess the burden of anemia on morbidity and mortality. We report here a cross-sectional analysis of the management of anemia, and response-to-treatment factors.

METHODS

A total of 1,710 patients were included (60% male, mean age 64.4 +/- 13.6 years, mean 16.2 +/- 11.1 months on HD) with a high comorbidity (hypertension 75.8%, diabetes 25.9%, heart failure 13.9% and coronary disease 16.7%) and a mean Charlson Index of 6.5 +/- 2.3.

RESULTS

There were 28.7% of patients who had started epoetin before end-stage renal disease (pre-ESRD), 81.4% of patients displayed Hb <11 g/dL when initiating HD with a mean Hb of 9.7 g/dL. Only 67.9% of prevalent HD patients attained a hemoglobin (Hb) level above 11 g/dL, 89.5% achieved a ferritin level above 100 ng/mL, 76.7% a transferrin saturation index (TSI) above 20%, and 61.1% met all 3 objectives. The multivariate analysis identified the following risk factors for Hb <11g/dL: low albumin (odds ratio, OR = 1.75), HD efficacy below objectives (OR = 1.44) and female sex (OR = 1.36), corrected for comorbidity, epoetin treatment, transfusion, surgery or hospital admission.

CONCLUSIONS

As compared with previous surveys, we found an improved but still inadequate anemia management in Spanish HD patients. Our results are comparable with those of Euro-DOPPS. Several modifiable factors related to a lower Hb concentration were assessed. On behalf of the MAR Study Group.

[Prospective monitoring of vascular access in hemodialysis by means of a multidisciplinary team]

PURPOSE

Nowadays, expert guidelines recommend the monitoring programs of the vascular access (VA) by a multidisciplinary team.

MATERIAL AND METHOD

We present the experience over the last five years, of a prospective VA surveillance by a multidisciplinary team. The quality indicators reached are described as the associated factors for survival of the new VA.

RESULTS

Three hundred seventeen VA have been studied, 73% were arteriovenous fistulas(AVF) and the rest were polytetrafluoroethylene (PTFE) grafts at 282 patients. The main causes of dysfunctions were elevated dynamic venous pressure (42.5%) and the decreased blood flow (36.4%) with a 88% of positive predictive value. Over the 5 years there was 88 thrombosis (24 AVF and 64 PTFE grafts), that means a hazard thrombosis global rate of 0.15 access/year, which were distributed in 0.06 for AVF and 0.38 in PTFE grafts. Two hundred and one repairs of VA were done: 66.6% were elective repair after a proper review by the multidisciplinary team and the rest of them were done after the AV thrombosis happened. Urgent rescue surgeries were done in 76% of the thrombosis. 62.5% of the patients did not need a catheter after vascular access thrombosis. The complication relation with AVF and PTFE were 11.4% of the total patients hemodialysis hospitalizations. 65.2% of the VA were new access. 57% of patients were properly reviewed in the pre-dialysis unit at least once and 80% of them start haemodialysis with a mature access. The average survival (Kaplan Meier) of the new AVF was 1,575+/-55 days vs 1,087+/-102 of the PTFE grafts (p < 0.008). The survival after 1, 2 and 3 years for the AVF was 89%, 85% and 83% and for the PTFE graft 3% 67% and 51% respectively. The Cox regression has proved that the type of vascular access is the strongest factor associated to VA survival. The survival added of VA repaired due to dysfunction was 1,062 +/- 97 days vs 707 +/- 132 due to thrombosis, log rank 5.17 (p < 0,02). The increasing risk of those repaired after a thrombosis vs dysfunction is 4.2 p < 0,01.

CONCLUSIONS

The monitoring of the vascular access by a multidisciplinary team has reached:low rate of thrombosis, high elective number of repairs of the VA, high urgent rescue surgery after a thrombosis and a few number catheter needed and hospitalizations. AVF are associated with greater survival than PTFE. The VA repair due to dysfunction vs thrombosis had a greater survival as well.

Exploring dosing frequency and administration routes in the treatment of anaemia in CKD patients

Erythropoiesis-stimulating agents have dramatically changed the management of renal anaemia since their introduction almost 20 years ago. However, optimal dosing route and frequency are still a matter of debate. Intravenous application of recombinant human erythropoietin should be limited to haemodialysis patients and must be given three times weekly, as any reduction to this dosing frequency leads to a major increase in dose requirements. Administering recombinant human erythropoietin-beta once weekly via the subcutaneous route is effective. If conversion from the subcutaneous to the intravenous route is required, dose requirements for recombinant human erythropoietin therapy remain a subject of discussion.

[Cardiovascular risk in hemodialysis in Spain: prevalence, management and target results (MAR study)]

Cardiovacular disease is the main cause of morbidity and mortality in hemodialysis (HD) patients. However, there are no reliable data neither on the prevalence of cardiovacular disease nor its risk factors in Spain. The Morbidity and mortality Anemia Renal study (MAR) is a two-year multicenter, open-label, prospective cohorts study. Its main objective is to assess the general morbidity and mortality, particularly of a cardiovascular cause, and its relationship with the degree of anemia. Secondary objectives are: a/ the description of current clinical practices in anemia, dialysis, vascular access, and CV risk factor management; and b/ the description of hospitalization and mortality causes. This paper describes the prevalence of cardiovascular disease and risk factors of the HD population in Spain. A total of 1.710 patients were included (60% male, aged 64.4 years, 16.2 months on HD). The mean co-morbidity Charlson index was 6.5 +/- 2.3. Cardiovascular disease was the most prevalent comorbidity, 16.7% had a coronary disease, and 13.9% had different degrees of heart failure, while 11.6% had arrhythmia, 1.7% stroke and 5.5% peripheral artery disease. The prevalence of hypertension was 75.8%, 74.4% of patients received antihypertensive drugs, and still 40% of patients had an inadequate blood pressure control. The investigators considered as dyslipidemic 34.1% of patients, and prescribed treatment to 69.5% of them, while the remaining 30.5% (10.4% of the total) had hyperlipidemia with no drug therapy. Eleven percent was active smoker, and 26.6% former smoker. There was 47.4% of patients with a corporal mass index above 25. Secondary hyperparathyroidism with PTH above of 300 pg/ml was present in 22.2% of patients. Despite the EBPG and K-DOQI recommendations, only 68.8% of prevalent hemodialysis patients attained a hemoglobin (Hb) above 11 g/dl, 89.4% ferritin levels above 100 ng/ml, 66.5 degrees/a a transferrin saturation index (TSI) above 20%, and 61.1% met all three objectives. In summary, this first cross-sectional analysis has allowed us to know in detail the standard practice in multiple aspects of management of HD population in Spain. It has also established clear differences in the prevalence of cardiovascular disease and risk factors from the US registries. Last but not least we have identified therapeutic opportunities to improve the course and prognosis of our patients.

Erythropoietin requirements: a comparative multicenter study between peritoneal dialysis and hemodialysis

BACKGROUND

The management of anemia with erythropoietin (EPO) is important in the global treatment of dialysis patients. There is a general impression that anemia control with EPO is obtained more easily in peritoneal dialysis (PD) patients than in hemodialysis (HD) patients. The EPO administration route has to be the same to compare the two techniques adequately.

METHODS

To compare EPO action by subcutaneous (SC) route in HD and PD, 132 stable patients were recruited (HD: 69, PD: 63) from six centers, with adequate dialysis criteria (Kt/V in HD >1.3; weekly Kt/V in PD >1.8). In a cross-sectional study, the EPO dose/week, the number of EPO doses/week, hemoglobin (Hb), ferritin, transferrin saturation index (TS), albumin and intact parathyroid hormone (iPTH) were analyzed. Iron treatment, comorbidity and ACE inhibitors (ACEI) and angiotensin II antagonist (AIIA) treatment were recorded. A multivariate regression model was used in the statistical analysis.

RESULTS

The mean Hb level was the same in both groups, HD 11.6 (1.3) g/dL, PD 11.4 (1.4) g/dL, p=0.3. The SC, EPO doses required to obtain the Hb levels were higher in HD than in PD patients, with a difference of 64.3 u/Kg/week, statistically significant in the multivariate regression model (p=0.001, 95% CI 42.6-86.0). The number of EPO doses/week was also higher in HD patients (65% of HD patients with > or = 3 doses, 19% of PD patients with three or more doses, p<0.001). TS was similar in both groups, while ferritin was higher in HD patients, with a higher percentage of HD patients using intravenous (i.v.) iron (HD 77% vs. PD 49%, p=0.001). Serum albumin and iPTH were lower in PD patients (p<0.001 and p=0.04, respectively), but the percentage of patients with intact parathyroid hormone (iPTH) >500 pg/mL was similar in both groups (HD 17%, PD 14%).

CONCLUSIONS

With the same administration route, PD patients showed a reduced EPO requirement, and less frequent EPO administration than HD patients, to obtain the same Hb level. No other factors, except those involved in better depuration of erythropoiesis inhibitors in PD, seemed responsible for the different EPO requirements.

The beneficial effects of intervention in early renal disease

In renal disease, anaemia is a risk factor for cardiovascular disease (CVD), such as left ventricular hypertrophy (LVH), in both dialysis patients and patients with early renal disease. During the past decade, many studies have showed that partial correction of anaemia leads to partial regression of LVH in hypertensive and normotensive dialysis patients. Several reports support the pre-dialysis use of epoetin. Evidence of cardiovascular risk reduction with epoetin treatment in pre-dialysis patients is growing. For example, in an open, prospective study of epoetin in pre-dialysis patients, an increase in mean haemoglobin of 2.7 g/dl was accompanied by a decrease in left ventricular mass index in almost all patients. This regression, obtained in the absence of improved blood pressure (BP) control, confirms the role of anaemia in the genesis of LVH. These results have been confirmed in two recent studies. Risk reduction strategies (i.e. BP control, lipid lowering, smoking cessation, anaemia correction) from the earliest stages of renal disease may facilitate the prevention of cardiovascular conditions such as LVH in chronic renal failure (CRF) patients. Indeed, if all the well recognized risk factors (including anaemia) are aggressively identified and treated, then long-term reductions in cardiovascular morbidity and mortality should be achieved. In conclusion, preliminary studies show reversal of hypertrophy after correction of renal anaemia with epoetin. Extrapolation of results from studies in CRF suggests the use of earlier treatment of anaemia to maximize cardiovascular benefits. Further studies of the cardiovascular benefits of earlier epoetin intervention in early renal disease are indicated.

Cardiovascular effects of recombinant human erythropoietin in predialysis patients

Treatment with recombinant human erythropoietin (rHuEPO) has solved the problem of anemia in patients on dialysis. However, its application to predialysis patients has raised some doubts about its effects on the progression of renal disease and on blood pressure (BP) and hemodynamic regulation. We have prospectively studied over at least 6 months a group of 11 predialysis patients receiving rHuEPO treatment (initial dose, 1,000 U subcutaneously three times a week). Clinical assessment and biochemical and hematologic measurements were made once every 2 weeks. Twenty-four-hour ambulatory BP monitoring, echocardiography, and determination of neurohumoral mediators of hemodynamics were performed once every 3 months. An adequate hematologic response was found (hemoglobin, 11.7 +/- 0.4 g/dL v 9 +/- 0.3 g/dL) without changes in the progression of renal disease. A decrease in cardiac output and an increase in total peripheral resistance was seen as anemia improved. A trend toward decreased left ventricular (LV) thickness and a significant decrease in LV mass index (from 178.2 +/- 20.6 g/m2 to 147.3 +/- 20.6 g/m2) were observed. Blood pressure control did not improve; moreover, in some patients an increase in systolic values was detected by ambulatory BP. Casual BP remained seemingly stable. Sequential determinations of neurohumoral mediators of hemodynamic substances (endothelin, renin, norepinephrine, epinephrine, dopamine) failed to explain these results. Ambulatory BP reveals a worse control in some patients who were previously hypertensive and confirms the utility of this technique in the assessment of patients under erythropoietin treatment. The trend toward LV hypertrophy regression without improved BP control confirms the role of anemia among the multiple factors leading to LV hypertrophy in end-stage renal disease (ESRD), and opens therapeutic possibilities. Better control of BP may avoid a potential offsetting of beneficial effects that correcting anemia would have on the cardiovascular system.