The phagocytosis dysfunction in lupus nephritis is related to monocyte/macrophage CPT1a

Macrophages must remove apoptotic cells to shield tissues from the deleterious components of dying cells. The development of chronic inflammation and autoimmune symptoms in systemic lupus is influenced by a deficiency in phagocytosis of apoptotic cells but the underlying mechanism is still unknown. Modifications in monocyte/macrophage phenotype brought on by an increase in their inflammatory phenotype would cause them to decrease the expression of CPT1a, which would reduce their ability to phagocytose, aggravating kidney damage in lupus nephritis. We aim to demonstrate that the deficiency of CPT1A in the immunological system determines lupus. For this purpose, we will monitor CPT1a expression in blood monocytes and phagocytosis and CPT1a expression of macrophages isolated from kidneys and the inflammatory state in kidneys in two experimental models of lupus nephritis such as lupus induced pristane model and in the OVA-IC in vivo model. Additionally, we will test if reestablishing CPT1a expression in tissue macrophages restores the lost phagocytic function. We evidenced that blood monocytes and macrophages isolated from kidneys in the two in vivo models have a reduced expression of CPT1a and a reduced phagocytosis. Phagocytosis could be restored only if macrophage administration leads to an increase in CPT1a expression in kidney macrophages. A new cell therapy to reduce kidney nephritis in lupus could be developed based on these results.

Practical consensus for the treatment and follow-up of primary aldosteronism: a multidisciplinary consensus document

Primary aldosteronism (PA) is the most frequent cause of secondary hypertension and is associated with a higher cardiometabolic risk than essential hypertension. The aim of this consensus is to provide practical clinical recommendations for its surgical and medical treatment, pathology study and biochemical and clinical follow-up, as well as for the approach in special situations like advanced age, pregnancy and chronic kidney disease, from a multidisciplinary perspective, in a nominal group consensus approach of experts from the Spanish Society of Endocrinology and Nutrition (SEEN), Spanish Society of Cardiology (SEC), Spanish Society of Nephrology (SEN), Spanish Society of Internal Medicine (SEMI), Spanish Radiology Society (SERAM), Spanish Society of Vascular and Interventional Radiology (SERVEI), Spanish Society of Laboratory Medicine (SEQC(ML)), Spanish Society of Anatomic-Pathology and Spanish Association of Surgeons (AEC).

Screening and diagnosis of primary aldosteronism. Consensus document of all the Spanish Societies involved in the management of primary aldosteronism

Primary aldosteronism (PA) is the most frequent cause of secondary hypertension (HT), and is associated with a higher cardiometabolic risk than essential HT. However, PA remains underdiagnosed, probably due to several difficulties clinicians usually find in performing its diagnosis and subtype classification. The aim of this consensus is to provide practical recommendations focused on the prevalence and the diagnosis of PA and the clinical implications of aldosterone excess, from a multidisciplinary perspective, in a nominal group consensus approach by experts from the Spanish Society of Endocrinology and Nutrition (SEEN), Spanish Society of Cardiology (SEC), Spanish Society of Nephrology (SEN), Spanish Society of Internal Medicine (SEMI), Spanish Radiology Society (SERAM), Spanish Society of Vascular and Interventional Radiology (SERVEI), Spanish Society of Laboratory Medicine (SEQC(ML)), Spanish Society of Anatomic-Pathology, Spanish Association of Surgeons (AEC).

Assessment of Individualized Mean Perfusion Pressure Targets for the Prevention of Cardiac Surgery-Associated Acute Kidney Injury-The PrevHemAKI Randomized Controlled Trial

BACKGROUND

Retrospective studies support that mean perfusion pressure (MPP) deficit in cardiac surgery patients is associated with a higher incidence of acute kidney injury (CS-AKI). The aim of our study was to apply an algorithm based on MPP in the postoperative period to determine whether management with an individualized target reduces the incidence of CS-AKI.

METHODS

Randomized controlled trial of patients undergoing cardiac surgery with extracorporeal circulation. Adult patients submitted to valve replacement and/or bypass surgery with a high risk of CS-AKI evaluated by a Leicester score >30 were randomized to follow a target MPP of >75% of the calculated baseline or a standard hemodynamic management during the first postoperative 24 h.

RESULTS

Ninety-eight patients with an eGFR of 54 mL/min were included. There were no differences in MAP and MPP in the first 24 h between the randomized groups, although a higher use of noradrenaline was found in the intervention arm (38.78 vs. 63.27, p = 0.026). The percentage of time with MPP < 75% of measured baseline was similar in both groups (10 vs. 12.7%, p = 0.811). MAP during surgery was higher in the intervention group (73 vs. 77 mmHg, p = 0.008). The global incidence of CS-AKI was 36.7%, being 38.6% in the intervention group and 34.6% in the control group (p = 0.40). There were no differences in extrarenal complications between groups as well.

CONCLUSION

An individualized hemodynamic management based on MPP compared to standard treatment in cardiac surgery patients was safe but did not reduce the incidence of CS-AKI in our study.

The coexistence of diabetic retinopathy and diabetic nephropathy is associated with worse kidney outcomes

Background

Up to 50-60% of patients with diabetes have non-diabetic kidney disease (NDKD) on kidney biopsy. Diabetic retinopathy (DR) is a microvascular complication of diabetes frequently associated with diabetic nephropathy (DN). The objective of the current study was to investigate the kidney outcomes and survival in patients with biopsy diagnoses of DN and NDKD according to the presence of DR.

Methods

We conducted an observational, multicentre and retrospective study of the pathological findings of renal biopsies from 832 consecutive patients with diabetes from 2002 to 2014 from 18 nephrology departments. The association of DR with kidney replacement therapy (KRT) or survival was assessed by Kaplan-Meier and Cox regression analyses.

Results

Of 832 patients with diabetes and renal biopsy, 768 had a retinal examination and 221/768 (22.6%) had DR. During a follow-up of 10 years, 288/760 (37.9%) patients with follow-up data needed KRT and 157/760 (20.7%) died. The incidence of KRT was higher among patients with DN (alone or with NDKD) and DR [103/175 (58.9%)] than among patients without DR [88/216 (40.7%), P < .0001]. The incidence of KRT was also higher among patients with only NDKD and DR than among those without DR [18/46 (39.1%) versus 79/331 (23.9%), P < .0001]. In multivariate analysis, DR or DN were independent risk factors for KRT {hazard ratio [HR] 2.48 [confidence interval (CI) 1.85-3.31], P < .001}. DN (with or without DR) was also identified as an independent risk factor for mortality [HR 1.81 (CI 1.26-2.62), P = .001].

Conclusions

DR is associated with a higher risk of progression to kidney failure in patients with histological DN and in patients with NDKD.

Impact of cardiac surgery associated acute kidney injury on 1-year major adverse kidney events

Background

The incidence of acute kidney injury following cardiac surgery (CSA-AKI) is up to 30%, and the risk of chronic kidney disease (CKD) has been found to be higher in these patients compared to the AKI-free population. The aim of our study was to assess the risk of major adverse kidney events (MAKE) [25% or greater decline in estimated glomerular filtration rate (eGFR), new hemodialysis, and death] after cardiac surgery in a Spanish cohort and to evaluate the utility of the score developed by Legouis D et al. (CSA-CKD score) in predicting the occurrence of MAKE.

Methods

This was a single-center retrospective study of patients who required cardiac surgery with cardiopulmonary bypass (CPB) during 2015, with a 1-year follow-up after the intervention. The inclusion criteria were patients over 18 years old who had undergone cardiac surgery [i.e., valve substitution (VS), coronary artery bypass graft (CABG), or a combination of both procedures].

Results

The number of patients with CKD (eGFR < 60 mL/min) increased from 74 (18.3%) to 97 (24%) within 1 year after surgery. The median eGFR declined from 85 to 82 mL/min in the non-CSA-AKI patient group and from 73 to 65 mL/min in those with CSA-AKI (p = 0.024). Fifty-eight patients (1.4%) presented with MAKE at the 1-year follow-up. Multivariate logistic regression analysis showed that the only variable associated with MAKE was CSA-AKI [odds ratio (OR) 2.386 (1.31-4.35), p = 0.004]. The median CSA-CKD score was higher in the MAKE cohort [3 (2-4) vs. 2 (1-3), p < 0.001], but discrimination was poor, with a receiver operating characteristic curve (AUC) value of 0.682 (0.611-0.754).

Conclusion

Any-stage CSA-AKI is associated with a risk of MAKE after 1 year. Further research into new measures that identify at-risk patients is needed so that appropriate patient follow-up can be carried out.

[Characterization of hospitalized patients with acute kidney injury associated with COVID-19 in Spain: Renal replacement therapy and mortality. FRA-COVID SEN Registry Data]

Background and objectives

Acute kidney injury (AKI) is common among hospitalized patients with COVID-19 and associated with worse prognosis. The Spanish Society of Nephrology created the AKI-COVID Registry to characterize the population admitted for COVID-19 that developed AKI in Spanish hospitals. The need of renal replacement therapy (RRT) therapeutic modalities, and mortality in these patients were assessed.

Material and method

In a retrospective study, we analyzed data from the AKI-COVID Registry, which included patients hospitalized in 30 Spanish hospitals from May 2020 to November 2021. Clinical and demographic variables, factors related to the severity of COVID-19 and AKI, and survival data were recorded. A multivariate regression analysis was performed to study factors related to RRT and mortality.

Results

Data from 730 patients were recorded. A total of 71.9% were men, with a mean age of 70 years (60-78), 70.1% were hypertensive, 32.9% diabetic, 33.3% with cardiovascular disease and 23.9% had some degree of chronic kidney disease (CKD). Pneumonia was diagnosed in 94.6%, requiring ventilatory support in 54.2% and admission to the ICU in 44.1% of cases.The median time from the onset of COVID-19 symptoms to the appearance of AKI (37.1% KDIGO I, 18.3% KDIGO II, 44.6% KDIGO III) was 6 days (4-10). A total of 235 (33.9%) patients required RRT: 155 patients with continuous renal replacement therapy, 89 alternate-day dialysis, 36 daily dialysis, 24 extended hemodialysis and 17 patients with hemodiafiltration. Smoking habit (OR 3.41), ventilatory support (OR 20.2), maximum creatinine value (OR 2.41) and time to AKI onset (OR 1.13) were predictors of the need for RRT; age was a protective factor (0.95). The group without RRT was characterized by older age, less severe AKI, shorter kidney injury onset and recovery time (p < 0.05). 38.6% of patients died during hospitalization; serious AKI and RRT were more frequent in the death group. In the multivariate analysis, age (OR 1.03), previous chronic kidney disease (OR 2.21), development of pneumonia (OR 2.89), ventilatory support (OR 3.34) and RRT (OR 2.28) were predictors of mortality while chronic treatment with ARBs was identified as a protective factor (OR 0.55).

Conclusions

Patients with AKI during hospitalization for COVID-19 had a high mean age, comorbidities and severe infection. We defined two different clinical patterns: an AKI of early onset, in older patients that resolves in a few days without the need for RRT; and another more severe pattern, with greater need for RRT, and late onset, which was related to greater severity of the infectious disease. The severity of the infection, age and the presence of CKD prior to admission were identified as risk factors for mortality in these patients. In addition chronic treatment with ARBs was identified as a protective factor for mortality.

Humoral response after the fourth dose of the SARS-CoV-2 vaccine in the CKD spectrum: a prespecified analysis of the SENCOVAC study

Background

There is scarce evidence on fourth doses of SARS-CoV-2 vaccines in chronic kidney disease (CKD) patients. We have evaluated the humoral response and effectivity of the fourth dose in the CKD spectrum: non-dialysis CKD (ND-CKD), hemodialysis (HD), peritoneal dialysis (PD) and kidney transplant (KT) recipients.

Methods

This is a prespecified analysis of the prospective, observational, multicentric SENCOVAC study. In patients with CKD who had received a complete initial vaccination and one or two boosters and had anti-Spike antibody determinations 6 and 12 months after the initial vaccination, we analyzed factors associated to persistent negative humoral response and to higher anti-Spike antibody titers as well as the efficacy of vaccination on COVID-19 severity.

Results

Of 2186 patients (18% KT, 8% PD, 69% HD and 5% ND-CKD), 30% had received a fourth dose. The fourth dose increased anti-Spike antibody titers in HD (P = 0.001) and ND-CKD (P = 0.014) patients and seroconverted 72% of previously negative patients. Higher anti-Spike antibody titers at 12 months were independently associated to repeated exposure to antigen (fourth dose, previous breakthrough infections), previous anti-Spike antibody titers and not being a KT. Breakthrough COVID-19 was registered in 137 (6%) patients, of whom 5% required admission. Admitted patients had prior titers below 620 UI/ml and median values were lower (P = 0.020) than in non-admitted patients.

Conclusions

A fourth vaccine dose increased anti-Spike antibody titers or seroconverted many CKD patients, but those with the highest need for a vaccine booster (i.e. those with lower pre-booster antibody titers or KT recipients) derived the least benefit in terms of antibody titers. Admission for breakthrough COVID-19 was associated with low anti-Spike antibody titers.

Creatine Kinase Elevation in Autosomal Dominant Polycystic Kidney Disease Patients on Tolvaptan Treatment

<b><i>Background:</i></b> Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary cause of end-stage kidney disease. Currently, tolvaptan is the only treatment that has proven to delay disease progression. The most notable side effect of this therapy is drug-induced liver injury; however, recently, there have been two reports of creatine kinase (CK) elevation in ADPKD patients on tolvaptan treatment. We set out to monitor and determine the actual incidence of CK elevation and evaluate its potential association with other clinical factors. <b><i>Methods:</i></b> This is an observational retrospective multicenter study performed in rapidly progressive ADPKD patients on tolvaptan treatment from Barcelona, Spain. Laboratory tests, demographics, treatment dose, and reported symptoms were collected from October 2018 to March 2021. <b><i>Results:</i></b> Ninety-five patients initiated tolvaptan treatment during follow-up. The medication had to be discontinued in 31 (32.6%) patients, primarily due to aquaretic effects (12.6%), elevated liver enzymes (8.4%), and symptomatic or persistently elevated CK levels (3.2%). Moreover, a total of 27 (28.4%) patients had elevated CK levels, with most of them being either transient (12.6%), mild and asymptomatic (4.2%), or resolved after dose reduction (3.2%) or temporary discontinuation (2.1%). <b><i>Conclusion:</i></b> We pre­sent the largest cohort that has monitored CK levels in a real-life setting, finding them elevated in 28.4% of patients. More research and monitoring will help us understand the clinical implications and the pathophysiological mechanism of CK elevation in this population.

New Insights Into Diuretic Use to Treat Congestion in the ICU: Beyond Furosemide

Diuretics are commonly used in critically ill patients with acute kidney injury (AKI) and fluid overload in intensive care units (ICU), furosemide being the diuretic of choice in more than 90% of the cases. Current evidence shows that other diuretics with distinct mechanisms of action could be used with good results in patients with selected profiles. From acetazolamide to tolvaptan, we will discuss recent studies and highlight how specific diuretic mechanisms could help to manage different ICU problems, such as loop diuretic resistance, hypernatremia, hyponatremia, or metabolic alkalosis. The current review tries to shed some light on the potential use of non-loop diuretics based on patient profile and give recommendations for loop diuretic treatment performance focused on what the intensivist and critical care nephrologist need to know based on the current evidence.

Syndrome of inappropriate antidiuretic hormone secretion

Hyponatremia is the most frequent electrolytic disorder in hospitalized patients, and the syndrome of inappropriate secretion of antidiuretic hormone (SIADH), the most frequent cause of hiponatremia with clinically normal extracellular volume. It consists of a disorder of the regulation of body water that obeys to different causes, mainly cancer, pulmonary illnesses, disorders of the central nervous system and diverse drugs. As in any hiponatremia it a physiological knowledge of the regulation of body water and sodium is essential as well as the application of precise diagnostic criteria in order to manage the problem with an effective treatment. The available data until the moment show that the clinical diagnosis of SIADH made by professionals is mainly not supported on the established criteria drawn by experts and this lack of accuracy probably hits in the therapeutic result. The basis of the treatment of the SIADH is to correct its cause, water restriction, solutes (sodium chloride) and the use of vaptans in case of failure of the previous measures.

MO315: Risk Factors for CSA-AKI and Performance of Leicester Score in a Spanish Cohort

BACKGROUND AND AIMS

The incidence of acute kidney injury following cardiac surgery (CSA-AKI) is up to 30% and it places patients at an increased risk of death. Leicester score (LS) is a new score designed by Birnie et al. [1] and validated in 2014 in a British Cohort. It predicts CSA-AKI at any stage with better discrimination compared with the Clevaland Clinic Score (CCS) and Euroscore II. The aim of this study was to identify risk factors for CSA-AKI and to assess the performance of LS in a Spanish cohort.

METHOD

A unicentric retrospective study of patients that required cardiac surgery with cardio-pulmonary bypass (CPB) during 2015 in the Hospital Clinic de Barcelona. The inclusion criteria were patients &gt;18 years old who were operated on for cardiac surgery [valve substitution (VS), coronary artery bypass graft (CABG) or a combination of both procedures] with the need of CPB. CSA-AKI was defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria.

RESULTS

A total of 444 patients were included, of which 171 (38.5%) developed CSA-AKI. The most frequent form of AKI was mild AKI (AKI stage 1), which was present in 105 patients (61.4%). AKI stage 3 was developed in 26 patients, 15 of which required RRT. A total of 66.7% of AKI cases met criteria in the first 24 h and the median duration until total recovery was 3 days. In the multivariate analysis, hypertension (OR 1.883), EGFR &lt; 60 mL/min (OR 2.365) and peripheral vascular disease (OR 4.66) were associated with CSA-AKI. Either discrimination or calibration were better with LS compared with CCS and Euroscore II, with an AUC of 0.721 versus 0.595 and 0.662, respectively (Fig. 1).

CONCLUSION

Preoperative hypertension in patients with CKD with or without peripheral vasculopathy can identify patients at risk of CSA-AKI. LS has proved to be a valid score that could be used to identify patients at risk who could benefit in intervention studies.

Patient Experience in Pancreas-Kidney Transplantation-A Methodological Approach Towards Innovation in an Established Program

Simultaneous pancreas-kidney transplantation (SPKT) leads to increased survival and quality of life, and is an alternative treatment for insulin-dependent diabetes mellitus and end-stage kidney disease. Due to the particularities of this population (often with multiple comorbidities) and of the surgery (only performed in a few centers), a comprehensive analysis of patients' experience along the SPKT process is crucial to improve patient care and add value to this procedure. Therefore, we applied a systematic and iterative methodology with the participation of both patients and professional teams working together to explore and identify unmet needs and value-adding steps along the transplant patient journey at an established pancreas transplant program. Four main steps (to comprehend, to explore, to experiment and to assess) led to several interventions around three major areas: Administration and logistics, information and communication, and perceived quality of assistance. As a result, both displacements to the hospital for diagnostic purposes and the time delay involved in joining the patient waiting list for transplantation were reduced in parallel to the administrative procedures. In conclusion, the methodological implementation of key organizational changes has great impact on overall patient experience. Further quantitative analysis from the patient's perspective will consolidate our program and may add new prototype service design components.

MO009: Creatine-Kinase Elevation in Autosomal Dominant Polycystic Kidney Disease Patients on Tolvaptan Treatment

BACKGROUND AND AIMS

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary cause of end-stage kidney disease. Currently, tolvaptan is the only treatment that has proven to delay disease progression. The most notable side-effect of this therapy is drug-induced liver injury; however, recently, there have been two reports of creatine kinase (CK) elevation in ADPKD patients on tolvaptan treatment. We set out to monitor and determine the actual incidence of CK elevation and evaluate its potential association with other clinical factors.

METHOD

This is an observational prospective multicenter study performed in rapidly progressive ADPKD patients on tolvaptan treatment from Barcelona, Spain. Laboratory tests, demographics, treatment dose and reported symptoms were collected from October 2018 to March 2021.

RESULTS

Ninety-five patients initiated tolvaptan treatment during follow-up. The medication had to be discontinued in 31 (32.6%) patients, primarily due to aquaretic effects (12.6%), elevated liver enzymes (8.4%) and symptomatic or persistently elevated CK levels (3.2%). Moreover, a total of 27 (28.4%) patients elevated CK levels, with most of them being either transient (12.6%), mild and asymptomatic (4.2%), or resolved after dose reduction (3.2%) or temporary discontinuation (2.1%).

CONCLUSION

We present the largest cohort that has monitored CK levels in a real-life setting, finding them elevated in 28.4% of patients. More research and monitoring will help us understand the clinical implications and the pathophysiological mechanism of CK elevation in this population.

MO783: Reduction of the Incidence of Dialysis Catheter-Associated Bacteraemia in Intensive Care Units after Systematic Application of Taurolock in the Sealing of the Catheter

BACKGROUND AND AIMS

Dialysis catheter-associated bacteraemia in Intensive Care Units (ICUs) increases morbidity and mortality, prolongs hospital admission and increases admission costs. TauroLock™ is a lock solution containing (cyclo)-taurolidine (1.35%) and citrate (4%). (Cyclo)-taurolidine has broad antimicrobial activity against gram-positive and gram-negative bacteria and fungi. The objective of this study was to analyse the effect of systematic sealing of haemodialysis catheters in the ICUs of the Hospital Clínic de Barcelona on the incidence of bacteraemia associated with haemodialysis catheters (BACH).

METHOD

BACH episodes of patients who underwent intermittent haemodialysis (IHD) during ICU admission were reviewed. The period analysed as pre-Taurolock™ was from 2010 to 2014 and post-TauroLock™ from 2015 to 2018. Patients who only received renal replacement therapy with continuous techniques were excluded.

RESULTS

A total of 279 patients received IHD in the pre-TauroLock™ period and 331 in the post-TauroLock™ period. The number of BACH in the pre-TauroLock™ period was 18 (6.45%) and 9 (2.72%) in the post-TauroLock™ period. All infections were from percutaneous catheters (acute patients) except three catheters that were tunnelled. In the pre-TauroLock™ period, femoral catheters predominated (61.1%) while in the post-TauroLock they were jugular (66.7%). There was no association between the location of the catheter and the incidence of BACH. Of the 27 patients with BACH, 14 (51.8%) were men with a mean age of 63 years, with no significant differences between the two groups. The most frequent reasons for admission to the ICU in the pre-TauroLock™ period were post-cardiac surgery, cardiogenic, septic or hypovolemic shock and acute myocardial infarction (3 patients per group) and in the post-TauroLock™ period, septic shock and pancreatitis (3 and 2 patients respectively). The most frequent isolated bacteria were Gram-positive (in total 48.38%: pre-TauroLock™ 47.61% and post-TauroLock™ 50%), with a global predominance of staphylococcus epidermidis (32.25%) (Table). There were no significant differences in the median days from the start of haemodialysis to bacteraemia (23.5 pre-TauroLock™ versus 21 post-TauroLock™). There were also no significant differences between the days of ICU stay in the BACH in both groups or in mortality, being the overall mortality of 70.4%.

CONCLUSION

In our cohort, the systematic application of TauroLock™ in the sealing of dialysis catheters in critically ill patients reduces the incidence of BACH in ICUs.

Incidence of severe breakthrough SARS-CoV-2 infections in vaccinated kidney transplant and haemodialysis patients

Introduction

Given the increased COVID-19 observed in kidney transplant recipients (KTRs) and haemodialysis patients, several studies have tried to establish the efficacy of mRNA vaccines in these populations by evaluating their humoral and cellular responses. However, there is currently no information on clinical protection (deaths and hospitalizations), a gap that this study aims to fill.

Methods

Observational prospective study involving 1,336 KTRs and haemodialysis patients from three dialysis units affiliated to Hospital Clínic of Barcelona, Spain, vaccinated with two doses of mRNA-1273 (Moderna) or BNT162b2 (Pfizer-BioNTech) SARS-CoV-2 mRNA vaccines. The outcomes measured were SARS-CoV-2 infection diagnosed by a positive RT-PCR fourteen days after the second vaccine dose, hospital admissions derived from infection, and a severe COVID-19 composite outcome, defined as either ICU admission, invasive and non-invasive mechanical ventilation, or death.

Results

Six per cent (18/302) of patients on haemodialysis were infected, of whom four required hospital admission (1.3%), only one (0.3%) had severe COVID-19, and none of them died. In contrast, 4.3% (44/1034) of KTRs were infected, and presented more hospital admissions (26 patients, 2.5%), severe COVID-19 (11 patients, 1.1%) or death (4 patients, 0.4%). KTRs had a significantly higher risk of hospital admission than HD patients, and this risk increased with age and male sex (HR 3.37 and 4.74, respectively).

Conclusions

The study highlights the need for booster doses in KTRs. In contrast, the haemodialysis population appears to have an adequate clinical response to vaccination, at least up to four months from its administration.

Graphical abstract

Management of acute renal replacement therapy in critically ill cirrhotic patients

Renal replacement therapy (RRT) in cirrhotic patients encompasses a number of issues related to the particular characteristics of this population, especially in the intensive care unit (ICU) setting. The short-term prognosis of cirrhotic patients with acute kidney injury is poor, with a mortality rate higher than 65% in patients with RRT requirement, raising questions about the futility of its initiation. Regarding the management of the RRT itself, there is still no consensus with respect to the modality (continuous versus intermittent) or the anticoagulation required to improve the circuit life, which is shorter than similar at-risk populations, despite the altered haemostasis in traditional coagulation tests frequently found in these patients. Furthermore, volume management is one of the most complex issues in this cohort, where tools used for ambulatory dialysis have not yet been successfully reproducible in the ICU setting. This review attempts to shed light on the management of acute RRT in the critically ill cirrhotic population based on the current evidence and the newly available tools. We will discuss the timing of RRT initiation and cessation, the modality, anticoagulation and fluid management, as well as the outcomes of the RRT in this population, and provide a brief review of the albumin extracorporeal dialysis from the point of view of a nephrologist.

The density of renal lymphatics correlates with clinical outcomes in IgA nephropathy

Introduction

IgA nephropathy (IgAN) is the most common primary glomerulonephritis (GN) worldwide. The disease course fluctuates, and the most important challenge is the considerable variation in the time lag between diagnosis and the development of a hard clinical end point, such as end-stage kidney disease (ESKD). The reaction of renal tissue to damage resembles the common wound-healing response. One part of this repair in IgAN is the expansion of lymphatic vessels known as lymphangiogenesis. The aim of this work was to establish the prognostic value of the density of lymphatic vessels in the renal biopsy at the time of diagnosis, for predicting the risk of ESKD in a Spanish cohort of patients with IgAN.

Methods

We performed a retrospective multicenter study of 76 patients with IgAN. The end point of the study was progression to ESKD. The morphometric analysis of lymphatic vessels was performed on tissue sections stained with antipodoplanin antibody.

Results

Density of lymphatic vessels was significantly higher in patients with IgAN with mesangial hypercellularity >50%, segmental sclerosis, higher degrees of interstitial fibrosis, and tubular atrophy. Patients with more lymphatic vessels had significantly higher values of proteinuria and lower estimated glomerular filtration rate (eGFR). A density of lymphatic vessels ≥8 per mm² was associated with a significantly higher rate of progression to ESKD at 3 years from biopsy. After adjustment for the International IgAN prediction score, at the multivariate logistic regression, high density of lymphatic vessels (≥8 per mm²) remained significantly associated with a higher rate of early progression to ESKD.

Conclusion

This study contributes to the understanding of the natural history of the progression to ESKD in patients with IgAN revealing the density of lymphatics vessels may optimize the prognostic value of the International IgA predicting tool to calculate the risk of ESKD, favoring the evaluation of new targeted therapies.

MO393ACUTE RENAL REPLACEMENT THERAPY IN CRITICAL ILL OCTOGENARIAN OR OLDER PATIENTS: PROGNOSTIC FACTORS AND RENAL OUTCOMES

Background and Aims

a growing number of octogenarians or older patients are being admitted to the intensive care unit (ICU). The aim of this study was to assess factors associated with acute renal replacement therapy (ARRT) requirement in these patients and the impact of ARRT on the 90-day ICU mortality. Also we aimed to identify prognostic factors associated with mortality risk in the group of patients that required ARRT.

Method

retrospective study of octogenarian or older patients admitted to the ICUs of Hospital Clínic de Barcelona from June 2007 to April 2019. Patients on chronic dialysis treatment or kidney transplant, and patients with limitation of therapeutic support or admitted for less than 48 hours were excluded.

Results

217 patients were included in the study, of which 36.4% required ARRT. Use of vasoactive drugs and Sequential Organ Failure Assessment (SOFA) score on admission were higher in ARRT patients (p=0.009 and &lt;0.001). Basal estimated glomerular filtration rate (eGFR) was lower in the ARRT cohort (p&lt;0.001). Hospital and ICU length of stay were longer in the ARRT cohort (p&lt;0.001). Ninety-day mortality was 58.2% in the ARRT cohort and 55.8% in the control cohort, without statistical differences. In the survival analysis, only female sex and non-renal SOFA ≥6.5 were significantly associated with mortality (p= 0.005 and 0.002 respectively) in the ARRT cohort.

Conclusion

mortality was not significatively increased in the octogenarian population that required and got ARRT respect to those who did not require it. Scores like SOFA can help in the process of decision making about initiation of ARRT.

MO405RISC FACTORS FOR CARDIAC SURGERY-ASSOCIATED ACUTE KIDNEY INJURY IN A TERTIARY REFERRAL HOSPITAL

Background and Aims

cardiac surgery-associated acute kidney injury (CS-AKI) is a frequent complication that confers significant increase in morbility and mortality. It is still unclear how to identify patients at high risk to develop it, in order to apply to them early preventive strategies to avoid AKI. The study aimed to explore risk factors associated to CS-AKI.

Method

to analyze the association between demographic, pre-operative and intraoperative variables with all grades-AKI, we collected baseline characteristics, type of surgery, aortic time of clampage and extracorporeal circulation time, hemodinamic variables during surgery, Euroscore II, Clevelant Clinic Score and Leicester cardiosurgery score. The post-operative variables included monitorization of the first 24 h in the Intensive Care Units (ICU), consistent in: use of vasoactive drugs, total diuresis, use of furosemide, need of transfusions and need and duration of renal replacement therapy (RRT). Creatinine was collected for all the admision days in order to calculate the incidence of AKI. Also mortality and need of RRT at 30 th day was assessed.

The inclusion criteria were: patients over 18 years old who underwent cardiac surgery with extracorporeal circulation. Only valve substitution (VS), Coronary Artery Bypass Graft (CABG) or a combination of both procedures (not including endocarditis surgery) were included. Patients who were already in dialysis or suffered an AKI just before the surgery were not included in the study.

Results

we included 130 patients who underwent heart surgery intervention in Hospital Clínic de Barcelona from 1st January to 31 st March 2015. 61,5% were men and the majority of them was 60 - 75 years old (46.9%), with hypertension (80.8%), without diabetes (68.5%), with stage 2-Chronic Kidney Disease (53.1%). Main surgical procedure was CABG (50.8%), followed by valve substitution (36.1%) and combination of both (13.1%). 73,1% of the procedures were done electively and 26.9% urgently. Out of the 130 patients, 60 (46.2%) suffered an AKI (36 AKIN 1, 16 AKIN 2 and 8 AKIN3). The majority of the episodes (55.2%) started between 24 and 48 hours after the intervention and 7 patients required RRT. AKI was not associated with mortality or need of renal replacement therapy at 30 days (OR 1.853, p= 0.397).

Regarding risk factors for CS-AKI, basal eGFR &lt;60 ml/min, history of hypertension, age and the clevelant/leicester and euroscore were preoperative risk factors associated with CS-AKI in our cohort (OR 5.571 p=&lt;0.001; OR 2.621 p=0.043; OR 1.036 p&lt;0.001; OR 1.453 p=0.045; OR 1.062 p&lt;0.001; OR 1.351 p=0.006 respectively). Leicester cardiosurgery score &gt;30 was the score who showed the best association with AKI (OR 5.167, p&lt;0.001). Intraoperative significant risk factors that were identified were: ischaemia time over 70 minutes (OR 2.876, p=0.004), and the need to use phenylephrine (3.064, p=0.015); whereas the need to use nitroglycerin was identified as a protector (OR 0.441, p=0.031).

Conclusion

previous eGFR&lt;60 ml/min, age, hypertension, use of phenylephrine during surgery and long ischaemia time are the main factors associated with CS-AKI. Scores like Leicester score can help physicians to identify people at risk and apply preventive strategies.

A hybrid data envelopment analysis-artificial neural network prediction model for COVID-19 severity in transplant recipients

In an overwhelming demand scenario, such as the SARS-CoV-2 pandemic, pressure over health systems may outburst their predicted capacity to deal with such extreme situations. Therefore, in order to successfully face a health emergency, scientific evidence and validated models are needed to provide real-time information that could be applied by any health center, especially for high-risk populations, such as transplant recipients. We have developed a hybrid prediction model whose accuracy relative to several alternative configurations has been validated through a battery of clustering techniques. Using hospital admission data from a cohort of hospitalized transplant patients, our hybrid Data Envelopment Analysis (DEA)—Artificial Neural Network (ANN) model extrapolates the progression towards severe COVID-19 disease with an accuracy of 96.3%, outperforming any competing model, such as logistic regression (65.5%) and random forest (44.8%). In this regard, DEA-ANN allows us to categorize the evolution of patients through the values of the analyses performed at hospital admission. Our prediction model may help guiding COVID-19 management through the identification of key predictors that permit a sustainable management of resources in a patient-centered model.

Acute renal replacement therapy in critically ill octogenarian or older patients: prognostic factors and renal outcomes

BACKGROUND

The number of octogenarians or older patients admitted to the intensive care unit (ICU) has been growing over the past several years. The aim of this study is to assess factors associated with acute renal replacement therapy (ARRT) requirement in these patients and the impact of this therapy on 90-day mortality. We also aimed to identify prognostic factors associated with mortality risk in the group of patients that required ARRT.

METHODS

Retrospective study of octogenarian or older patients admitted to the ICU at Hospital Clínic de Barcelona from June 2007 to April 2019. Patients on chronic dialysis treatment or with a kidney transplant, and patients with limitation of therapeutic support or admitted for less than 48 h were excluded.

RESULTS

217 patients were included in the study, of whom 36.4% required ARRT. Use of vasoactive drugs (VAD) and Sequential Organ Failure Assessment (SOFA) score on admission were higher in ARRT patients (P = 0.009 and < 0.001, respectively). Basal estimated glomerular filtration rate (eGFR) was lower in the ARRT cohort (P < 0.001). Hospital and ICU length of stay were longer in the ARRT cohort (P < 0.001). Ninety-day mortality was 58.2% in the ARRT cohort compared to 55.8% in the non-ARRT control cohort (P = NS). In the survival analysis, only female sex, sepsis and non-renal SOFA ≥ 6.5 were significantly associated with mortality (P = 0.002, 0.028 and 0.009, respectively) in the ARRT cohort.

CONCLUSION

Mortality was not significantly increased in the octogenarian or older population that required and received ARRT compared to control patients who did not require it. Severity scores like SOFA could help in the process of decision making about initiation of ARRT in this population.

Thrombotic microangiopathies assessment: mind the complement

When faced with microangiopathic haemolytic anaemia, thrombocytopenia and organ dysfunction, clinicians should suspect thrombotic microangiopathy (TMA). The endothelial damage that leads to this histological lesion can be triggered by several conditions or diseases, hindering an early diagnosis and aetiological treatment. However, due to systemic involvement in TMA and its low incidence, an accurate early diagnosis is often troublesome. In the last few decades, major improvements have been made in the pathophysiological knowledge of TMAs such as thrombotic thrombocytopenic purpura [TTP, caused by ADAMTS-13 (a disintegrin and metalloproteinase with a thrombospondin Type 1 motif, member 13) deficiency] and atypical haemolytic uraemic syndrome (aHUS, associated with dysregulation of the alternative complement pathway), together with enhancements in patient management due to new diagnostic tools and treatments. However, diagnosis of aHUS requires the exclusion of all the other entities that can cause TMA, delaying the introduction of terminal complement blockers, which have shown high efficacy in haemolysis control and especially in avoiding organ damage if used early. Importantly, there is increasing evidence that other forms of TMA could present overactivation of the complement system, worsening their clinical progression. This review addresses the diagnostic and therapeutic approach when there is clinical suspicion of TMA, emphasizing complement evaluation as a potential tool for the inclusive diagnosis of aHUS, as well as for the improvement of current knowledge of its pathophysiological involvement in other TMAs. The development of both new complement activation biomarkers and inhibitory treatments will probably improve the management of TMA patients in the near future, reducing response times and improving patient outcomes.

Severe acute kidney injury in critically ill COVID-19 patients

BACKGROUND

Acute kidney injury (AKI) is frequent in Coronavirus Infection Disease 2019 (COVID-19) patients. Factors associated with AKI in COVID-19 intensive care unit (ICU) patients and their outcomes have not been previously explored.

METHODS

Prospective observational study of COVID-19 patients admitted to the ICUs of the Hospital Clínic of Barcelona (Spain), from March 25th to April 21st, 2020, who developed AKI stage 2 or higher (AKIN classification). The primary goal was to describe the characteristics of moderate-severe AKI of COVID-19 patients in an ICU context. As a secondary goal, we aimed to find independent predictors of AKI progression, Renal Replacement Therapy (RRT) requirement and mortality among these patients.

RESULTS

During the study period, 52 out of 237 ICU patients, developed AKIN stage 2 or higher and were included in the study. A Sequential Organ Failure Assessment (SOFA) score at AKI diagnosis of 8 or higher was associated with RRT, OR 5.2, p 0.032. At the time of AKI diagnosis, patients had a worse liver profile and higher inflammation markers than at admission. Fifty per cent of the patients presented AKI progression from AKIN 2 to 3 and 28.85% required RRT. The use of corticosteroids in 69.2% of patients was associated with a reduced requirement of RRT, OR 0.13 (CI 95% 0.02-0.89), p 0.037. AKI was associated with high mortality (50%) and a longer hospital stay, median 35 vs 18 days (p 0.024).

CONCLUSIONS

The prevalence of moderate/severe AKI in COVID-19 patients admitted to the ICU is high and has a strong correlation with mortality and length of hospital stay.

Oral hydration compared to intravenous hydration in the prevention of post-contrast acute kidney injury in patients with chronic kidney disease stage IIIb: A phase III non-inferiority study (NICIR study)

OBJECTIVE

To evaluate the non-inferiority of oral hydration compared to intravenous (i.v.) hydration in the prevention of post-contrast acute kidney injury (PC-AKI) in patients with stage IIIb chronic kidney disease (CKD) referred for an elective contrast-enhanced computed tomography (CE-CT).

MATERIAL AND METHODS

This is a prospective, randomized, phase 3, parallel-group, open-label, non-inferiority trial. Patients were randomly assigned 1:1 to receive prophylaxis against PC-AKI either with oral hydration: 500 mL of water two hours before and 2000 mL during the 24 h after performing CE-CT or i.v. hydration: sodium bicarbonate (166 mmol/L) 3 mL/kg/h starting one hour before and sodium bicarbonate (166 mmol/L) 1 mL/kg/h during the first hour after CE-CT. 100 mL of non-ionic iodinated contrast was administered in all cases. The primary outcome was the proportion of PC-AKI in the first 48-72 h after CE-CT. Secondary outcomes were persistent PC-AKI, the need for hemodialysis, and the occurrence of adverse events related to prophylaxis.

RESULTS

Of 264 patients randomized between January 2018 and January 2019, 114 received oral hydration, and 114 received i.v. hydration and were evaluable. No significant differences were found (p > 0.05) between arms in clinical characteristics or risk factors. PC-AKI rate was 4.4 % (95 %CI: 1.4-9.9 %) in the oral hydration arm and 5.3 % (95 %CI: 2.0-11.1%) in the i.v. hydration arm. The persistent PC-AKI rate was 1.8 % (95 %CI: 0.2-6.2 %) in both arms. No patient required dialysis during the first month after CE-CT or had adverse effects related to the hydration regime.

CONCLUSION

In those with stage IIIb CKD referred for an elective CE-CT, we provide evidence of non-inferiority of oral hydration compared to i.v. hydration in the prevention of PC-AKI.

Impact of locking solutions on conditioning biofilm formation in tunnelled haemodialysis catheters and inflammatory response activation

INTRODUCTION

The surface of tunnelled cuffed catheters provides an optimal environment for the development of biofilms, which have recently been described as conditioning films because of the presence of adherent biological materials. These biofilms are associated with infection and thrombosis and potentially increase patients' inflammatory response. These complications could be reduced by the use of locking solutions.

OBJECTIVE

To analyse biofilm formation, using confocal and electron microscopy, in tunnelled cuffed catheters locked with three different solutions and to determine the relationship between these solutions and inflammatory response.

STUDY DESIGN

This prospective study included 35 haemodialysis patients with tunnelled cuffed catheter removal for non-infection-related reasons. The participants were divided into three groups according to the lock solution used: (1) heparin 1: 5000 IU; (2) citrate 4%; and (3) taurolidine 1.35%, citrate 4% and heparin 500 IU (taurolock); in the latter group, 25,000 IU taurolidine-urokinase was used in the last weekly session. All tunnelled cuffed catheters were cultured, and the inner surface was evaluated with confocal and electron microscopy. The inflammatory profile of included patients was determined at tunnelled cuffed catheter removal.

RESULTS

There were no differences in clinical or demographic variables between the three subgroups. Biofilm thickness was lower in the taurolidine group than in the citrate 4% and heparin groups (28.85 ± 6.86 vs 49.99 ± 16.56 vs 56.2 ± 15.67 µm, respectively; p < 0.001), as was biofilm volume (1.01 ±1.18 vs 3.7 ± 2.15 vs 5.55 ±2.44, µm³, respectively; p < 0.001). The mean interleukin-6 value was 39%, which was 50% lower than in the citrate and heparin groups, but without significance differences.

CONCLUSION

Our results show that biofilms were found in all tunnelled cuffed catheters, but the thickness and volume were significantly lower in tunnelled cuffed catheters locked with taurolidine solution. Therefore, the type of locking solution used in tunnelled cuffed catheters should maintain tunnelled cuffed catheter sterility and prevent catheter-related bloodstream infections. No significant difference was observed in the inflammatory profile according to the type of locking solution.

Pregnancy-Related Complications in Patients With Fibromuscular Dysplasia: A Report From the European/International Fibromuscular Dysplasia Registry

Current literature suggests a higher risk of pregnancy-related complications in patients with renal fibromuscular dysplasia (FMD). The aim of our study was to assess the nature and prevalence of pregnancy-related complications in patients subsequently diagnosed with FMD. A call for participation was sent to centers contributing to the European/International FMD Registry. Patients with at least 1 pregnancy were included. Data on pregnancy were collected through medical files and FMD characteristics through the European/International FMD Registry. Data from 534 pregnancies were obtained in 237 patients. Despite the fact that, in 96% of cases, FMD was not diagnosed before pregnancy, 40% of women (n=93) experienced pregnancy-related complications, mostly gestational hypertension (25%) and preterm birth (20%), while preeclampsia was reported in only 7.5%. Only 1 patient experienced arterial dissection and another patient an aneurysm rupture. When compared with patients without pregnancy-related complications, patients with complicated pregnancies were younger at FMD diagnosis (43 versus 51 years old; P<0.001) and had a lower prevalence of cerebrovascular FMD (30% versus 52%; P=0.003) but underwent more often renal revascularization (63% versus 40%, P<0.001). In conclusion, the prevalence of pregnancy-related complications such as gestational hypertension and preterm birth was high in patients with FMD, probably related to the severity of renal FMD. However, the prevalence of preeclampsia and arterial complications was low/moderate. These findings emphasize the need to screen hypertensive women for FMD to ensure revascularization before pregnancy if indicated and appropriate follow-up during pregnancy, without discouraging patients with FMD from considering pregnancy.

Development of chronic kidney disease after acute kidney injury in patients with cirrhosis is common and impairs clinical outcomes

BACKGROUND & AIMS

Acute kidney injury (AKI) is common in cirrhosis and is associated with poor prognosis. In patients who survive after AKI, it is not known whether the acute injury leads to chronic impairment of kidney function (chronic kidney disease [CKD]). The aim of the study was to determine the frequency of CKD at 3 months after an AKI episode and its effects on patient outcomes.

METHODS

Patients admitted for complications of cirrhosis during a 6.5-year period were evaluated using the same protocol, with assessment of kidney function at regular intervals during and after hospitalization. CKD was defined as estimated glomerular filtration rate (eGFR) <60 ml/min/1.73m² at 3 months after AKI.

RESULTS

A total of 409 patients (168 with AKI and 241 without AKI) were included. After 3 months, 97 patients with AKI and 188 patients without AKI had survived. Of the 97 patients with AKI, 24 had developed CKD at 3 months compared to only 2 of the 188 patients without AKI (25% vs. 1%, odds ratio 31; p <0.0001). Risk factors independently associated with CKD were nosocomial AKI and severity of AKI (stage ≥1B). At diagnosis of CKD, all patients had stage 3A CKD and one-quarter of them progressed to stages 3B and 4 after 1 year. The transition from AKI to CKD was associated with an increased rate of 3-month hospital readmission, increased frequency of AKI, bacterial infections, ascites, and refractory ascites and a trend towards a higher need for liver transplantation. Transplant-free survival was not impaired.

CONCLUSIONS

CKD frequently develops in patients with cirrhosis who survive AKI and has a negative impact on relevant clinical outcomes. The transition from AKI to CKD is common and should be considered a high-risk condition in patients with cirrhosis.

LAY SUMMARY

Episodes of acute impairment of kidney function are common in patients with cirrhosis. This study shows that the development of chronic impairment of kidney function is frequent in patients surviving these acute episodes and that it is associated with a higher risk of developing other complications of cirrhosis and to a higher rate of 3-month hospital readmissions.

P0485ASSOCIATION BETWEEN ANTI-GBM TITERS AND KIDNEY INFLAMMATION MEASURED BY A NEW ACTIVITY SCORE

Background and Aims

Anti-glomerular basement membrane (anti-GBM) disease is an aggressive and rare glomerulopathy characterized by rapidly progressive loss of kidney function, leading to end stage kidney disease (ESKD) in a significant amount of cases. The main objective of our study was to determine whether anti-GBM titer correlated with the rate of activity in renal biopsy and long-term kidney survival in patients with anti-GBM, hence identifying patients who would potentially benefit from more intensive treatments.

Method

A retrospective analysis was performed on the cases of anti-GBM from our center that had both a positive biopsy and serology, from 2007 to 2019. Epidemiological data, anti-GBM levels on admission, kidney function at admission, discharge and follow-up, treatment and kidney biopsy findings were collected. All biopsies were reevaluated by a single, blinded pathologist and nephrologist. Based on a recent study by van Daalen et al, a chronicity and activity histopathological score was developed. The score was divided in glomerular and interstitial sections. In the glomerular section, a sclerotic pattern (&gt;50% of glomeruli) was given 0 points in activity and 3 in chronicity, a mixed pattern was given 1 point in activity and chronicity, and a crescentic pattern (&gt;50% with cellular crescents) was given 3 points in activity and 0 in chronicity. In the interstitial section, the presence of fibrosis and atrophy was given between 0 and 3 points in chronicity and the presence of tubulitis or interstitial infiltrate were given points in activity (0 to 1 and 0 to 3 respectively). The presence of neutrophils in the infiltrate was given one extra point in activity. Spearman correlation was performed between anti-GBM levels and our biopsy score.

Results

Twelve cases were identified, with a median Anti-GBM titer at admission of 292 U/mL (IQR 40-1517). Ten patients were treated with cyclophosphamide, 1 with rituximab plus cyclophosphamide and 1 with only rituximab. All patients received treatment with metilprednisona and plasma exchange with a median number of sessions of 8 (range: 6-12). Only one patient was not in ESKD during follow-up (35 months), so correlation with long-term kidney survival could not be performed. On the other hand, high antibody titers correlated with more activity on biopsy (correlation coefficient 0.592, p= 0.042) and less chronicity (correlation coefficient -0.657, p= 0.02).

Conclusion

These results suggest that patients who present with higher titers have more acute inflammation and less chronicity in renal parenchima, and therefore could benefit from more intensive treatment that changes the natural history of this aggressive disease. It would be interesting to study this score in larger and multicentric cohorts in order to produce more definitive conclusions.

Complement as the enabler of carfilzomib-induced thrombotic microangiopathy

Carfilzomib has been associated with the development of thrombotic microangiopathy (TMA) in relapsed/refractory multiple myeloma patients, a severe disease with no currently available aetiological treatment. We evaluated the potential role of terminal complement pathway in four patients with carfilzomib-induced TMA. Membrane attack complex (C5b-9) deposition on endothelial cells in culture exposed to plasma from patients during the acute phase of the disease suggests complement overactivation as a mechanism of potential endothelial damage in three out of four patients. If confirmed in larger cohorts, C5b-9 evaluation will allow early identification of patients who could benefit from complement blockade and treatment monitoring.

The European/International Fibromuscular Dysplasia Registry and Initiative (FEIRI)-clinical phenotypes and their predictors based on a cohort of 1000 patients

AIMS

Since December 2015, the European/International Fibromuscular Dysplasia (FMD) Registry enrolled 1022 patients from 22 countries. We present their characteristics according to disease subtype, age and gender, as well as predictors of widespread disease, aneurysms and dissections.

METHODS AND RESULTS

All patients diagnosed with FMD (string-of-beads or focal stenosis in at least one vascular bed) based on computed tomography angiography, magnetic resonance angiography, and/or catheter-based angiography were eligible. Patients were predominantly women (82%) and Caucasians (88%). Age at diagnosis was 46 ± 16 years (12% ≥65 years old), 86% were hypertensive, 72% had multifocal, and 57% multivessel FMD. Compared to patients with multifocal FMD, patients with focal FMD were younger, more often men, had less often multivessel FMD but more revascularizations. Compared to women with FMD, men were younger, had more often focal FMD and arterial dissections. Compared to younger patients with FMD, patients ≥65 years old had more often multifocal FMD, lower estimated glomerular filtration rate and more atherosclerotic lesions. Independent predictors of multivessel FMD were age at FMD diagnosis, stroke, multifocal subtype, presence of aneurysm or dissection, and family history of FMD. Predictors of aneurysms were multivessel and multifocal FMD. Predictors of dissections were age at FMD diagnosis, male gender, stroke, and multivessel FMD.

CONCLUSIONS

The European/International FMD Registry allowed large-scale characterization of distinct profiles of patients with FMD and, more importantly, identification of a unique set of independent predictors of widespread disease, aneurysms and dissections, paving the way for targeted screening, management, and follow-up of FMD.

The renal range of the κ/λ sFLC ratio: best strategy to evaluate multiple myeloma in patients with chronic kidney disease

Background

Monoclonal serum free light chains (sFLC) are a well-known cause of renal impairment (RI) in patients with multiple myeloma (MM). As an indicator of monoclonality, sFLC ratio has acquired a key role in the diagnosis and monitorization of the disease. However, its interpretation is altered in patients with chronic kidney disease (CKD). This study aims to evaluate the modification of the sFLC ratio reference range in patients with CKD, and propose an optimal range for patients with CKD.

Methods

Serum FLC κ/λ ratio and estimated glomerular filtration rate (eGFR) were retrospectively analyzed in 113 control patients (without hematologic disease), 63 patients with MM in complete remission and 347 patients with active MM. The three groups included patients with CKD (eGFR < 90).

Results

In the group of patients without active MM (n = 176), the sFLC ratio increased at different stages of CKD without pathological significance, with an increase in the number of false positives specially when eGFR is ≤55 ml/min. An optimal range was established for patients with eGFR ≤55 ml/min/1.73 m2: 0.82–3,6 with maximum sensitivity + specificity for that group with an improvement in the Area under the curve (AUC), 0.91 (0.84–0.97) compared with the current ranges proposed by Katzmann and Hutchinson.

Conclusions

This study confirms the influence of eGFR on the interpretation of the sFLC ratio, showing a decreasing specificity in progressive CKD stages when using the reference sFLC range (Katzmann), especially in patients with eFGR ≤55. According to our results, we suggest a modified optimal range (0.82–3,6) for eGFR ≤55 ml/min/1.73 m2. It is necessary to validate this modified range in larger and prospective studies.

Successful use of nonantigen-specific immunoadsorption with antihuman Ig-columns in kidney graft antibody-mediated rejection

INTRODUCTION

Nonantigen-specific immunoadsorption (IA) has proven to be effective in acute antibody-mediated rejection (aAMR). However, there is a lack of solid studies evaluating the safety and efficacy of IA with antihuman Ig-columns in aAMR. For chronic-active AMR (cAMR), no studies have evaluated the efficacy of nonantingen-specific IA with antihuman Ig-columns. The purpose of this study was to evaluate the role of nonantigen-specific IA with antihuman Ig-columns in the treatment of both aAMR and cAMR in kidney transplantation.

MATERIAL AND METHODS

In retrospective and observational study, kidney graft and recipient survival rates were assessed after treatment of aAMR and cAMR with nonantigen-specific IA with Ig-Flex columns (Therasorb) between January 2012 and May 2018. Protocols included nonantigen-specific IA, rituximab, intravenous immunoglobulin, and rescue plasma exchange, if necessary.

RESULTS

The study included 14 patients with AMR (acute in 9, chronic active in 5). For aAMR, mean follow-up was 13 ± 6 months, and patient and graft survival were, respectively, of 100% and 83%, with a mean increase in estimated glomerular filtration rate (eGFR) of 7.98 ± 12.96, 10.18 ± 16.71, and 11.43 ± 13.85 mL/min/1.72 m² (P > .05) at 3, 12 months after treatment, and at the end of follow-up, respectively. For cAMR, mean follow-up was 14 ± 8 months, and patient and graft survival were, respectively, of 100% and 60%, with an average increase in eGFR of 4.30 ± 7.86, 5.64 ± 10.47, and 14.5 ± 7.86 mL/min/m² (P > .05) at 3, 12 months after IA treatment, and at the end of the follow-up, respectively, although 40% did not respond and required chronic hemodialysis.

CONCLUSION

Nonantigen-specific IA with Ig-Flex columns was safe and effective for aAMR treatment in kidney transplantation. In cAMR, IA with Ig-Flex columns was associated with a satisfactory kidney graft survival, suggesting that IA could potentially offer some benefits supporting its indication in cAMR.

IgA Nephropathy Recurrence after Kidney Transplantation: Role of Recipient Age and Human Leukocyte Antigen-B Mismatch

BACKGROUND

Recurrence of immunoglobulin (Ig)A nephropathy (rIgAN) is a growing cause of kidney allograft dysfunction. This study was aimed at investigating factors associated with rIgAN and the subsequent progression to end-stage renal disease (ESRD).

METHODS

Retrospective study including consecutive patients with IgA nephropathy (IgAN) who received a kidney transplant in our center between 1992 and 2016 and had a renal biopsy by clinical indication. The date of detection of chronic kidney disease (CKD) 5 was used as renal outcome.

RESULTS

Eighty-six kidney transplants were performed in patients with IgAN, 38 (44%) were from living donors (related n = 26). rIgAN was diagnosed in 23 allografts (27%). Renal function and proteinuria at the end of the follow-up period were worst in the rIgAN patients compared to those without rIgAN (2.2 vs. 1.4 mg/dL, p = 0.014, and 1.16 vs. 0.49 g/day, p = 0.005, respectively). Risk of rIgAN and progression to CKD 5 decreased with patient's age (hazard ratio [HR] 0.95, 95% CI 0.92-0.98, p = 0.002, and HR 0.97, 95% CI 0.83-0.97, p = 0.008 per year, respectively). Patients with rIgAN had a higher risk of progression to CKD 5 (HR 6.7, 95% CI 1.3-35.7, p = 0.025). Full donor-recipient mismatch in the human leukocyte antigen (HLA)-B loci decreased the risk of rIgAN (HR 0.22, 95% CI 0.06-0.76, p = 0.017).

CONCLUSIONS

rIgAN was an independent risk factor for ESRD after renal allograft. Younger age increased the risk of rIgAN and CKD 5. Conversely, HLA-B mismatching was a potential protective factor for rIgAN of this glomerular disease.

Risk factors for non-diabetic renal disease in diabetic patients

Background

Diabetic patients with kidney disease have a high prevalence of non-diabetic renal disease (NDRD). Renal and patient survival regarding the diagnosis of diabetic nephropathy (DN) or NDRD have not been widely studied. The aim of our study is to evaluate the prevalence of NDRD in patients with diabetes and to determine the capacity of clinical and analytical data in the prediction of NDRD. In addition, we will study renal and patient prognosis according to the renal biopsy findings in patients with diabetes.

Methods

Retrospective multicentre observational study of renal biopsies performed in patients with diabetes from 2002 to 2014.

Results

In total, 832 patients were included: 621 men (74.6%), mean age of 61.7 ± 12.8 years, creatinine was 2.8 ± 2.2 mg/dL and proteinuria 2.7 (interquartile range: 1.2–5.4) g/24 h. About 39.5% (n = 329) of patients had DN, 49.6% (n = 413) NDRD and 10.8% (n = 90) mixed forms. The most frequent NDRD was nephroangiosclerosis (NAS) (n = 87, 9.3%). In the multivariate logistic regression analysis, older age [odds ratio (OR) = 1.03, 95% CI: 1.02–1.05, P < 0.001], microhaematuria (OR = 1.51, 95% CI: 1.03–2.21, P = 0.033) and absence of diabetic retinopathy (DR) (OR = 0.28, 95% CI: 0.19–0.42, P < 0.001) were independently associated with NDRD. Kaplan–Meier analysis showed that patients with DN or mixed forms presented worse renal prognosis than NDRD (P < 0.001) and higher mortality (P = 0.029). In multivariate Cox analyses, older age (P < 0.001), higher serum creatinine (P < 0.001), higher proteinuria (P < 0.001), DR (P = 0.007) and DN (P < 0.001) were independent risk factors for renal replacement therapy. In addition, older age (P < 0.001), peripheral vascular disease (P = 0.002), higher creatinine (P = 0.01) and DN (P = 0.015) were independent risk factors for mortality.

Conclusions

The most frequent cause of NDRD is NAS. Elderly patients with microhaematuria and the absence of DR are the ones at risk for NDRD. Patients with DN presented worse renal prognosis and higher mortality than those with NDRD. These results suggest that in some patients with diabetes, kidney biopsy may be useful for an accurate renal diagnosis and subsequently treatment and prognosis.

Complement Activation and Thrombotic Microangiopathies

BACKGROUND AND OBJECTIVES

Atypical hemolytic uremic syndrome is a form of thrombotic microangiopathy caused by dysregulation of the alternative complement pathway. There is evidence showing complement activation in other thrombotic microangiopathies. The aim of this study was to evaluate complement activation in different thrombotic microangiopathies and to monitor treatment response.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Complement activation was assessed by exposing endothelial cells to sera or activated-patient plasma-citrated plasma mixed with a control sera pool (1:1)-to analyze C5b-9 deposits by immunofluorescence. Patients with atypical hemolytic uremic syndrome (n=34) at different stages of the disease, HELLP syndrome (a pregnancy complication characterized by hemolysis, elevated liver enzymes, and low platelet count) or severe preeclampsia (n=10), and malignant hypertension (n=5) were included.

RESULTS

Acute phase atypical hemolytic uremic syndrome-activated plasma induced an increased C5b-9 deposition on endothelial cells. Standard and lower doses of eculizumab inhibited C5b-9 deposition in all patients with atypical hemolytic uremic syndrome, except in two who showed partial remission and clinical relapse. Significant fibrin formation was observed together with C5b-9 deposition. Results obtained using activated-plasma samples were more marked and reproducible than those obtained with sera. C5b-9 deposition was also increased with samples from patients with HELLP (all cases) and preeclampsia (90%) at disease onset. This increase was sustained in those with HELLP after 40 days, and levels normalized in patients with both HELLP and preeclampsia after 6-9 months. Complement activation in those with malignant hypertension was at control levels.

CONCLUSIONS

The proposed methodology identifies complement overactivation in patients with atypical hemolytic uremic syndrome at acute phase and in other diseases such as HELLP syndrome and preeclampsia. Moreover, it is sensitive enough to individually assess the efficiency of the C5 inhibition treatment.

Neutrophil Gelatinase-Associated Lipocalin for Assessment of Acute Kidney Injury in Cirrhosis: A Prospective Study

Kidney biomarkers appear to be useful in differential diagnosis between acute tubular necrosis (ATN) and other types of acute kidney injury (AKI) in cirrhosis, particularly hepatorenal syndrome (HRS-AKI). Distinction is important because treatment is different. However, kidney biomarkers are still not used in clinical practice. The aim of the current study was to investigate the accuracy of several biomarkers in differential diagnosis of AKI and in predicting kidney outcome and patient survival. This was a prospective study of 320 consecutive cases of AKI in patients hospitalized for decompensated cirrhosis. Evaluation of AKI was made with a diagnostic algorithm that included identification and removal/treatment of precipitating factors and albumin administration (1 g/kg for 2 days) to patients with AKI stage 1B or greater. Urinary neutrophil gelatinase-associated lipocalin (NGAL), monomeric NGAL (mNGAL), interleukin-18, and standard biomarkers were measured at diagnosis and on days 3, 7, and 14. Of the 320 cases, 153 were hypovolemia-induced AKI (48%), 93 were HRS-AKI (29%), 39 were ATN (12%), and 35 were due to miscellaneous causes (11%). Among all biomarkers, urinary NGAL measured at day 3 had the greatest accuracy for differential diagnosis between ATN and other types of AKI (area under the receiver operating characteristic curve, 0.87; 95% confidence interval, 0.78-0.95). The cutoff with the best predictive accuracy for ATN diagnosis was 220 µg/g creatinine. Progression of AKI during hospitalization was associated with persistently high NGAL levels, and NGAL was an independent predictive factor of AKI progression. Likewise, NGAL was also an independent predictive factor of 28-day mortality together with Model for End-Stage Liver Disease score. Conclusion: These results support the use of NGAL in clinical practice within the context of a diagnostic algorithm for differential diagnosis of AKI and outcome prediction in cirrhosis.

An update on tolvaptan for autosomal dominant polycystic kidney disease

Tolvaptan is an orally active antagonist of vasopressin (antidiuretic hormone [ADH]) V2 receptors. By blocking water reabsorption in kidney collecting ducts, it prompts renal free-water excretion and has been used for the treatment of hyponatremia, both euvolemic due to the syndrome of inappropriate ADH secretion, and hypervolemic due to liver cirrhosis and congestive heart failure. In the past few years, it has been shown that vasopressin and its second messenger cyclic adenosine monophosphate (cAMP) play an important role in the pathogenesis of autosomal dominant polycystic kidney disease (ADPKD). This has been the rationale for the use of tolvaptan to halt the progression of ADPKD, mainly through slowing kidney growth and decline in renal function. Two major randomized clinical trials have demonstrated the benefits of tolvaptan in slowing the progression of ADPKD in terms of kidney growth and decline in renal function at 1 and 3 years (REPRISE and TEMPO). However, the long-term effectiveness of treatment with tolvaptan remains to be determined.

High cut-off membrane for in-vivo dialysis of free plasma hemoglobin in a patient with massive hemolysis

Background

The possibility of clearing Cell-free Plasma Hemoglobin (CPH) from human plasma may appear attractive, especially when considering the noxious effects that CPH has on the immune function and the renal damage caused by its filtration. The existence of the so-called High Cut-Off (HCO) filters, possessing pores as big as 60 kDa, could potentially allow the clearance of the αβ dimers (31.3 kDa), the form in which the α2β2 hemoglobin tetramers (62.6 kDa) physiologically dissociate in plasma. We present herein the first reported case in which such an attempt was made.

Case presentation

The patient was a 51-year-old man with hemolytic crisis due to glucose-6-phosphate dehydrogenase deficiency, further complicated by pigment-induced nephropathy. He underwent a 48-h CVVHD session, in which a HCO filter was used. The Sieving Coefficient (SC) for CPH was initially 0.08 and decreased to 0.02 after 24 h. This unexpected low SC was due to the initial high concentration of CPH (4.24 g/L). At such concentrations, the α2β2 tetramer poorly dissociates into the αβ dimer; but increases exponentially at concentrations lower than 1 g/L.

Conclusions

Clearance of CPH through a HCO filter is technically feasible but its performance markedly relies on the initial concentration of CPH. Critically ill patients with smoldering hemolysis, as it happens during septic shock or ECMO treatment, may benefit the most from the use of this membrane in order to clear CPH.