Investigational agents for autosomal dominant polycystic kidney disease: preclinical and early phase study insights

INTRODUCTION

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most common inherited kidney condition caused by a single-gene mutation. It leads patients to kidney failure in more than 50% of cases by the age of 60, and, given the dominant inheritance, this disease is present in the family history in more than 90% of cases.

AREAS COVERED

This review aims to analyze the set of preclinical and early-phase studies to provide a general view of the current progress on ADPKD therapeutic options. Articles from PubMed and the current status of the trials listed in clinicaltrials.gov were examined for the review.

EXPERT OPINION

Many potential therapeutic targets are currently under study for the treatment of ADPKD. A few drugs have reached the clinical phase, while many are currently still in the preclinical phase. Organoids could be a novel approach to the study of drugs in this phase. Other than pharmacological options, very important developing approaches are represented by gene therapy and the use of MiRNA inhibitors.

Fabry disease: a rare disorder calling for personalized medicine

Fabry Disease (FD) is a genetic disease caused by a deficiency in the activity of lysosomal galactosidase A (α-GalA), an enzyme responsible for the catabolism of globotriaosylceramide (Gb3). Since lysosomes are present throughout the body and play a crucial role in catabolism and recycling of cytosolic compounds, FD can affect multiple organs and result in various symptoms, including renal, cardiovascular, neurological, cutaneous, and ophthalmic manifestations. Due to the nonspecific symptoms and the rarity of FD, it is often diagnosed late in life. However, introducing targeted therapies such as enzyme replacement therapy (ERT) and chaperone therapy has significantly improved FD's natural history and prognosis by restoring α-GalA enzyme activity. Despite the advancements, there are limitations to the currently available therapies, which has prompted research into new potential treatments for FD, including alternative forms of enzyme replacement therapy, substrate reduction therapy, mRNA therapy, and genetic therapy. In this review, we analyze the epidemiology, pathophysiology, and treatment of FD, with particular emphasis on promising therapeutic opportunities that could shift the treatment of this rare disease from a standardized to a personalized approach soon.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

DNAJB11 Mutation in ADPKD Patients: Clinical Characteristics in a Monocentric Cohort

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a late-onset cilia-related disorder, characterized by progressive cystic enlargement of the kidneys. It is genetically heterogeneous with PKD1 and PKD2 pathogenic variants identified in approximately 78% and 15% of families, respectively. More recently, additional ADPKD genes, such as DNAJB11, have been identified and included in the diagnostic routine test for renal cystic diseases. However, despite recent progress in ADPKD molecular approach, approximately ~7% of ADPKD-affected families remain genetically unresolved. We collected a cohort of 4 families from our center, harboring heterozygous variants in the DNAJB11 gene along with clinical and imaging findings consistent with previously reported features in DNAJB11 mutated patients. Mutations were identified as likely pathogenetic (LP) in three families and as variants of uncertain significance (VUS) in the remaining one. One patient underwent to kidney biopsy and showed a prevalence of interstitial fibrosis that could be observed in ~60% of the sample. The presence in the four families from our cohort of ADPKD characteristics together with ADTKD features, such as hyperuricemia, diabetes, and chronic interstitial fibrosis, supports the definition of DNAJB11 phenotype as an overlap disease between these two entities, as originally suggested by the literature.

Fabry Disease Nephropathy: Histological Changes With Nonclassical Mutations and Genetic Variants of Unknown Significance

RATIONALE & OBJECTIVE

Fabry disease (FD) is an X-linked genetic disorder that causes lysosomal storage of glycosphingolipids, primarily globotriaosylceramide (Gb3) and its derivative globotriaosylsphingosine (lyso-Gb3), with multiorgan dysfunction including chronic kidney disease. Affected individuals may be carriers of gene variants that are of uncertain significance (GVUS). We describe kidney pathology at the early stages of FD-related kidney disease to gain insights into its association with GVUS and sex.

STUDY DESIGN

Single-center, case series.

SETTING & PARTICIPANTS

Thirty-five consecutively biopsied patients (aged 48.1±15.4 years, 22 females) from among 64 patients with genetically diagnosed FD. Biopsies were retrospectively screened using the International Study Group of Fabry Nephropathy Scoring System.

OBSERVATIONS

Genetic mutation type, p.N215S and D313Y, sex, age, estimated glomerular filtration rate (eGFR), plasma lyso-Gb3 (pLyso-Gb3) levels, and histological parameters, including Gb3 deposits were recorded. Genetic analyses showed mostly missense mutations, p.N215S variant in 15, and the "benign polymorphism" D313Y in 4 of the biopsied patients. Morphological lesions were similar for men and women except for interstitial fibrosis and arteriolar hyalinosis being more common in men. Early in their clinical course, patients with normal/mild albuminuria had podocyte, tubular, and peritubular capillary vacuoles/inclusions, and evidence of chronicity, i.e., glomerulosclerosis, interstitial fibrosis, tubular atrophy. These findings appeared to be associated with pLyso-Gb3, eGFR, and age.

LIMITATIONS

Retrospective design and inclusion of outpatients partially based on family pedigree.

CONCLUSIONS

In early stages of kidney disease in the setting of FD, numerous histological abnormalities are present. These observations suggest that kidney biopsies early in FD may reveal activity of kidney involvement that may inform clinical management.

Electrocardiogram analysis in Anderson-Fabry disease: a valuable tool for progressive phenotypic expression tracking

Background

Electrocardiogram (ECG) has proven to be useful for early detection of cardiac involvement in Anderson-Fabry disease (AFD); however, little evidence is available on the association between ECG alterations and the progression of the disease.

Aim and Methods

To perform a cross sectional comparison of ECG abnormalities throughout different left ventricular hypertrophy (LVH) severity subgroups, providing ECG patterns specific of the progressive AFD stages. 189 AFD patients from a multicenter cohort underwent comprehensive ECG analysis, echocardiography, and clinical evaluation.

Results

The study cohort (39% males, median age 47 years, 68% classical AFD) was divided into 4 groups according to different degree of left ventricular (LV) thickness: group A ≤ 9 mm (n = 52, 28%); group B 10-14 mm (n = 76, 40%); group C 15-19 mm (n = 46, 24%); group D ≥ 20 mm (n = 15, 8%). The most frequent conduction delay was right bundle branch block (RBBB), incomplete in groups B and C (20%,22%) and complete RBBB in group D (54%, p < 0.001); none of the patients had left bundle branch block (LBBB). Left anterior fascicular block, LVH criteria, negative T waves, ST depression were more common in the advanced stages of the disease (p < 0.001). Summarizing our results, we suggested ECG patterns representative of the different AFD stages as assessed by the increases in LV thickness over time (Central Figure). Patients from group A showed mostly a normal ECG (77%) or minor anomalies like LVH criteria (8%) and delta wave/slurred QR onset + borderline PR (8%). Differently, patients from groups B and C exhibited more heterogeneous ECG patterns: LVH (17%; 7% respectively); LVH + LV strain (9%; 17%); incomplete RBBB + repolarization abnormalities (8%; 9%), more frequently associated with LVH criteria in group C than B (8%; 15%). Finally, patients from group D showed very peculiar ECG patterns, represented by complete RBBB + LVH and repolarization abnormalities (40%), sometimes associated with QRS fragmentation (13%).

Conclusions

ECG is a sensitive tool for early identification and long-term monitoring of cardiac involvement in patients with AFD, providing "instantaneous pictures" along the natural history of AFD. Whether ECG changes may be associated with clinical events remains to be determined.

Modifiers of Autosomal Dominant Polycystic Kidney Disease Severity: The Role of PKD1 Hypomorphic Alleles

Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic cause of kidney failure in adult life. Rarely, ADPKD can be diagnosed in utero or in infancy, and the genetic mechanism underlying such severe presentation has been shown to be related to reduced gene dosage. Biallelic PKD1 variants are often identified in early onset ADPKD, with one main pathogenic variant and a modifier hypomorphic variant showing an in trans configuration. We describe two unrelated individuals with early onset cystic kidney disease and unaffected parents, where a combination of next-generation sequencing of cystic genes including PKHD1, HNF1B and PKD1 allowed the identification of biallelic PKD1 variants. Furthermore, we review the medical literature in order to report likely PKD1 hypomorphic variants reported to date and estimate a minimal allele frequency of 1/130 for this category of variants taken as a group. This figure could help to orient genetic counseling, although the interpretation and the real clinical impact of rare PKD1 missense variants, especially if previously unreported, remain challenging.

Diet and Physical Activity in Adult Dominant Polycystic Kidney Disease: A Review of the Literature

Autosomal polycystic kidney disease is the most common inherited kidney disease determining 5% of all end-stage kidney disease. The only therapy approved for this condition is Tolvaptan, which, with its aquaretic effect, has a strong effect on patients' daily life. Recently, the literature has been enriched with new works that analyze possible non-pharmacological therapeutic strategies to slow cysts' enlargement and chronic kidney disease progression. Among them, dietary schemes reducing carbohydrate intake and inducing ketoses have been demonstrated to have efficacy in several pre-clinical and clinical studies. A ketogenic diet, calorie restriction, intermittent fasting, and time-restricted feeding can reduce aerobic glycolysis and inhibit the mTOR pathway, producing a reduction in cyst cell proliferation, a reduction in kidney volume, and helping to preserve kidney function. ADPKD's burden of disease has an impact on patients' quality of life, and the possibility to play sports or carry out physical exercise can help people in everyday life. The multisystemic character of the disease, especially cardiovascular involvement, needs to be carefully evaluated to establish the quality and quantity of physical activity that patients can safely carry out.

Impact of Baseline Clinical Variables on SGLT2i's Antiproteinuric Effect in Diabetic Kidney Disease

INTRODUCTION

Proteinuria is a major risk factor for the progression of chronic kidney disease (CKD). Sodium-glucose cotransporter 2 inhibitors (SGLT2i) demonstrated a nephroprotective and antiproteinuric effect in people with type 2 diabetes (T2DM) and proteinuric CKD. We conducted a retrospective study to evaluate clinical and laboratory variables that can help predict proteinuria reduction with SGLT2i therapy.

MATERIALS AND METHODS

Patients affected by T2DM and CKD who started any SGLT2i were included in the study. Patients were stratified into two subgroups, Responder (R) and non-Responder (nR), based upon the response to the therapy with SGLT2i, namely the reduction in a 24 h urine proteins test (uProt) of ≥30% from baseline levels. The aim of the study is to analyse differences in baseline characteristics between the two groups and to investigate the relationship between them and the proteinuria reduction. A Kruskal-Wallis test, unpaired t-test and Chi² test were used to test the difference in means and the percentage (%) between the two groups. Linear and logistic regressions were utilized to analyse the relationship between proteinuria reduction and basal characteristics.

RESULTS

A total of 58 patients were enrolled in the study: 32 patients (55.1%) were in the R group and 26 patients (44.9%) in the nR group. R's patients had a significant higher uProt at baseline (1393 vs. 449 mg/24 h, p = 0.010). There was a significant correlation between baseline uProt and proteinuria reduction with SGLT2i in both univariate (β = -0.43, CI -0.55 to -031; p < 0.001) and multivariate analyses (β = -0.46, CI -0.57 to -0.35, p < 0.001). In the multivariate analysis, there was a significant positive correlation between the estimated glomerular filtration rate (eGFR) and proteinuria reduction (β = -17, CI -31 to -3.3, p = 0.016) and a significant negative correlation with body mass index (BMI) (β = 81, CI 13 to 50, p = 0.021). The multivariate logistic regressions show a positive correlation of being in the R group with diabetic retinopathy at baseline (Odds Ratio (OR) 3.65, CI 0.97 to 13.58, p = 0.054), while the presence of cardiovascular disease (CVD) at baseline is associated with being in the nR group (OR 0.34, CI 0.09 to 1.22, p = 0.1), even if these statements did not reach statistical significance.

CONCLUSIONS

In this real-life experience, following the administration of SGLT2i, a reduction of more than 30% in proteinuria was observed in more than half of the patients, and these patients had a significantly higher baseline proteinuria value. Variables such as eGFR and BMI are variables that, considered in conjunction with proteinuria, can help predict treatment response before therapy initiation. Different phenotypes of diabetic kidney disease may have an impact on the antiproteinuric response.

Medullary sponge kidney: unusual finding in kidney transplant recipient

Background

Medullary sponge kidney is generally considered a benign condition, gold standard for the diagnosis is urography but it has almost been replaced by UroCT that did not present the same sensibility. Although it is really rare, our sonography’s findings were consistent with medullary sponge kidney in the transplanted kidneys.

Case presentation

A 45-year-old woman with a long history of double-kidney transplantation complained of frequent urinary tract infections, a history of vague loin pain and came to our attention for sonography follow-up. Her kidney function was normal, we did not find signs of infections in the transplanted kidneys and urinary findings were normal. Curiously, the transplanted kidneys came from a newborn and the patient received a double-kidney transplantation in order to guarantee a satisfactory renal function.

Conclusions

Despite a long history of kidney transplantation, genetic disease should not be forgotten when symptoms and images recall to specific inherited alterations. Sonography has to be considered in diagnostic path of kidney cystic disease.

Impact of nephrotoxic drugs on urinary biomarkers of renal function in very preterm infants

BACKGROUND

Following preterm birth, the immature kidney is exposed to several harmful conditions, with an increased risk of renal impairment. We aimed to assess urinary biomarkers of renal function in very preterm infants during early nephrotoxic treatments.

METHODS

Infants ≤32 weeks' gestation and ≤1500 g were enrolled in this observational prospective study. Urine samples were collected on day 1(T1), 2-4(T2), 5-7(T3), 8-10(T4), 11-13(T5). The following urinary biomarkers were determined: osteopontin (uOPN), epidermal growth factor (uEGF), neutrophil gelatinase-associated lipocalin (uNGAL), cystatin C (uCysC). The infants were grouped according to their exposure to amikacin or ibuprofen during the study period and a between-group comparison of urinary biomarkers at each time point was performed.

RESULTS

Thirty-six infants were included. Urinary CysC, uOPN, and uNGAL rose significantly during ibuprofen or amikacin treatment, while no difference was observed for uEGF. After adjustment for possible influencing factors, amikacin administration was associated with higher uCysC at T1 (p = 0.007) and T2 (p = 0.016), whereas ibuprofen increased uOPN (p = 0.001) and uNGAL concentration (p = 0.009) at T3.

CONCLUSION

Nephrotoxic therapies induce molecule-specific change patterns of renal function biomarkers in treated preterm infants. Serial assessments of these biomarkers may aid to identify neonates at risk of renal impairment and to develop tailored therapeutic approaches.

IMPACT

Despite the wide use of nephrotoxic therapies in neonatal settings, little is known on their effect on renal function biomarkers in preterm infants. This study describes molecule-specific change patterns of urinary biomarkers during ibuprofen and amikacin administration, suggesting underlying pathophysiological effects on renal function. Given their low analytical costs and non-invasive collection, the urinary biomarkers investigated in this study represent a promising strategy for serial monitoring of renal function in at-risk neonates and may aid the early detection of renal function impairment at different kidney levels during nephrotoxic treatments.

Crystal nephropathy and amoxicillin: insights from international spontaneous reporting systems

BACKGROUND

A substantial increase in amoxicillin-induced crystal nephropathy was recently reported in France. Our study aims to further characterize this safety issue from a worldwide perspective.

METHODS

We queried both the FDA Adverse Event Reporting System (FAERS) and the Eudravigilance databases, and performed disproportionality analysis, selecting only adverse events (AEs) related to crystal nephropathy where amoxicillin or amoxicillin/clavulanic acid were reported as suspect. In FAERS, the reporting odds ratios were calculated and deemed significant by the lower limit of the 95% confidence interval (LL95%CI) > 1, selecting all other drugs/events recorded in FAERS as comparator. Deduplication followed by case-by-case assessment and comparison between French and non-French cases were also performed in both databases.

RESULTS

Overall, 57,754 and 84,764 AE reports with amoxicillin or amoxicillin/clavulanic acid were recorded in FAERS and Eudravigilance, respectively, with France accounting for 18.7% and 22.0% of cases. Specific AEs of interest were retrieved in 144 and 239 cases, respectively. Increased reporting was found in FAERS for crystalluria (N = 99; LL95%CI 53.18), crystal nephropathy (24; 27.01), medication crystal in urine present (9; 92.00), crystal urine (8; 11.90), and crystal urine present (4; 1.57). In FAERS and Eudravigilance databases, reports were classified as serious in 98.8% and 91.2% of cases, respectively. Acute kidney injury (AKI) was found in 81.2% and 71.1% of patients. Amoxicillin was mainly given intravenously, and a dose ≥ 12 g/day was administered in 50.0% and 19.7% of cases in the FAERS and Eudravigilance databases, respectively.

CONCLUSION

Although causal association cannot be firmly inferred, a consistent signal of crystal nephropathy with amoxicillin emerged, especially in France. Clinicians should monitor patients for possible early AKI onset, especially when dealing with intravenous administration of daily doses > 12 g.

The Relationship between Timing of Pretransplant Kidney Biopsy, Graft Loss, and Survival in Kidney Transplantation: An Italian Cohort Study

INTRODUCTION

Kidney biopsy is performed to assess if an extended criteria graft can be used for transplantation. It may be performed before or after cross-clamping during organ procurement. This study aims to evaluate whether the timing of biopsy may modify cold ischemia times (CIT) and/or graft outcomes.

METHODS

Kidney transplants performed in our center from January 2007 to December 2017 were analyzed. Grafts with preimplantation kidney biopsy were included. Biopsies were performed during surgical back table (ex situ kidney biopsy [ESKB]) until 2012 and since then before the aortic cross-clamping (in situ kidney biopsy [ISKB]). To overcome biases owing to different distributions, a propensity score model was developed. The study population consists in 322 patients, 115 ESKB, and 207 ISKB.

RESULTS

CIT was significantly lower for ISKB (730 min ISKB vs. 840 min ESKB, p value = 0.001). In both crude (OR 0.27; 95% confidence interval, 95% CI 0.12-0.60; p value = 0.002) and adjusted analyses (OR 0.37; 95% CI 0.14-0.94; p value = 0.039), ISKB was associated with a reduced odd of graft loss when compared to ESKB.

DISCUSSION/CONCLUSION

Performing preimplantation kidney biopsy during the recovery, prior to the aortic cross-clamping, may be a strategy to reduce CIT and improve transplant outcomes.

MR Brain Screening in ADPKD Patients : To Screen or not to Screen?

BACKGROUND

Adult polycystic kidney disease (ADPKD) still represents a major cause of renal failure and intracranial aneurisms (IA) have a higher prevalence in ADPKD than in the general population. Current guidelines suggest performing brain MRI only in the subjects with a positive familiar history of IAs or subarachnoid hemorrhage (SAH). This is a retrospective case-control analysis to evaluate the usefulness of a MR screening program in ADPKD patients.

METHODS

We retrospectively analyzed all ADPKD patients followed in our outpatient clinic between 2016 and 2019 who underwent a brain MRI screening. We evaluated the presence of IAs and others brain abnormalities and compared our results with a non-ADPKD population (n = 300). We performed univariate and multivariate regression analysis to evaluate if general and demographic features, laboratory findings, clinical parameters and genetic test results correlated with IAs or other brain abnormalities presence.

RESULTS

Among the patients evaluated 17 out of 156 (13.6%) ADPKD patients had IAs, compared to 16 out of 300 (5.3%) non-ADPKD controls (p < 0.005). Considering ADPKD patients presenting IAs, 12 (70.6%) had no family history for IAs or SAH. Genetic analysis was available for 97 patients: in the sub-population with IAs, 13 (76.5%) presented a PKD1 mutation and none a PKD2 mutation. We found that arachnoid cysts (AC) (p < 0.001) and arterial anatomical variants (p < 0.04) were significantly more frequent in ADPKD patients.

CONCLUSION

In our population ADPKD patients showed a higher prevalence of IAs, AC and arterial variants compared to non-ADPKD. Most of the IAs were found in patients presenting a PKD1 mutation. We found a significant number of alterations even in those patients without a family history of IAs or SAH. The practice of submitting only patients with familial IAs or kidney transplantation candidates to MRI scan should be re-evaluated.

The link between homocysteine, folic acid and vitamin B12 in chronic kidney disease

Patients with chronic kidney disease or end-stage renal disease experience tremendous cardiovascular risk. Cardiovascular events are the leading causes of death in these patient populations, thus the interest in non-traditional risk factors such as hyperhomocysteinemia, folic acid and vitamin B12 metabolism is growing. Hyperhomocysteinemia is commonly found in CKD patients because of impaired renal metabolism and reduced renal excretion. Folic acid, the synthetic form of vitamin B9, is critical in the conversion of homocysteine to methionine like vitamin B12. Folic acid has also been shown to improve endothelial function without lowering homocysteine, suggesting an alternative explanation for the effect of folic acid on endothelial function. Whether hyperhomocysteinemia represents a reliable marker of cardiovascular risk and cardiovascular mortality or a therapeutic target in this population remains unclear. However, it is reasonable to consider folic acid with or without methylcobalamin supplementation as appropriate adjunctive therapy in patients with CKD. The purpose of this review is to summarize the characteristics of homocysteine, folic acid, and vitamin B12 metabolism, the mechanism of vascular damage, and the outcome of vitamin supplementation on hyperhomocysteinemia in patients with CKD, ESRD, dialysis treatment, and in kidney transplant recipients.

Intravenous Iron Replacement Therapy Improves Cardiovascular Outcomes in Hemodialysis Patients

BACKGROUND/AIM

More than half of deaths among hemodialysis patients are due to cardiovascular disease. This study examined whether intravenous administration of ferric carboxymaltose (FCM) has an impact on cardiovascular events in iron-deficient hemodialysis patients.

PATIENTS AND METHODS

We performed a retrospective study concerning patients undergoing hemodialysis in our center from September 2016 to December 2019. We identified those who began FCM therapy (FCM group) during this period and those who did not (control group). We analyzed clinical, echocardiographic and laboratory parameters at the beginning (t0) and after one year (t1), to detect differences between the two groups.

RESULTS

We identified 53 patients for the FCM group and 19 for the control group. Median follow-up was 1 year±3 months for both groups. In the FCM group, we observed a reduction in the doses of erythropoiesis-stimulating agents (ESA) (p<0.001) and a significative difference in cardiovascular events (p<0.01), but no differences in echocardiographic parameters.

CONCLUSION

Patients who received FCM reached satisfactory values of transferrin saturation and ferritin, presented fewer coronary artery events and cardiovascular events, and could reduce doses of ESA.

MO772PRIMARY AND SECONDARY HYPEROXALURIA IN CHRONIC DIALYSIS PATIENTS: FOCUS ON VASCULAR ACCESS

Background and Aims

Hyperoxaluria is a rare metabolic disorder chacterized by widespread calcium oxalate deposition, if plasmatic oxalate level (pOx) overcomes saturation threshold. It could be primary (PH), a recessive disease associated with mutation of the liver enzyme LDH, or secondary (SH), in 75% due to intestinal malabsorption. Urolithiasis could be the first complication, and renal involvement could progress until end-stage renal disease (ESRD). Mean pOx is higher in chronic dialysis patients than healthy individuals because of impaired renal clearance. Oxalate molecular weight (MW) is 88 Da and its clearance is that of low MW uremic toxins. Our aim is to assess an association between arteriovenous fistula (AVF) failures and Hyperoxaluria.

Method

In the period between 1/1/2004 and 12/31/2020, diagnosis of Hyperoxaluria was carried out in 6 patients out of 1530 chronic dialysis patients (0.39%). The median age of patients was 65.5 [26-72] years, the male/female ratio was 3:3 and the median dialysis vintage was 36 [1-181] months. Three patients come to nephrological referral at stage 5 of CKD while 1 patient came to Italy when chronic HD was already started. At that time pOx was not considered. In these 4 patients the presumptive diagnosis of ESRD was urolithiasis and diagnosis of Hyperoxaluria was carried out after the beginning of chronic dialysis, when pOx and genetic analysis were performed. In 1 case biopsy on the kidney graft and in 1 case kidney biopsy after nephrectomy were performed: oxalate deposition was detected. For 2/6 patients diagnosis was carried out after biopsy of native kidneys before starting dialysis. All patients started medical therapy for hyperoxaluria. Five out of 6 patients were eligible to HD, 1/6 to PD. AVF was judged the first choice vascular access.

Results

PH was diagnosed in 3/6 patients: mutations were detected on chromosome 2. Malabsorption secondary to short bowel syndrome and chronic pancreatitis could be assumed as causes of SH in 3 patients. Patient 1 underwent 2 combined liver-kidney transplantation: the first failed by arterial grafts thrombosis and the second by renal primary non-function but the liver was still functioning, he died on HD after 12 years. Patient 2 underwent liver and kidney transplantation and she is nowadays dialysis-free. The median pOx pre-dialysis and before diagnosis was 165 [98-259] umol/L (Table 1).

Patients on chronic HD underwent median of 3 [2-5] AVF interventions. Nine AVFs were distal and 4 were proximal. The most frequent complication was AVF thrombosis despite ASA treatment: half of the cases showed secondary AVF non-function, the other half of AVFs failed to mature. Six tunneled cuffed permanent catheters (TCCs) as definitive vascular access were successfully placed in the 5 patients on chronic HD. Warfarin therapy was started to avoid TCCs thrombosis. The median survival of TCCs was 9.5 [3-48] months. All the patients had a history of deep venous thrombosis (DVT).

Conclusion

To our knowledge this is the first case series of multiple AVF failures in patients with hyperoxaluria. In our experience TCCs show longer survival then AVF in this group of patients, even if it could not be excluded the role of warfarin in favoring this result. Even though a link between hyperoxaluria and thrombosis is well established, the exact underlying mechanism is still uncleared. The role of PD as dialysis technique of “first choice” should be enhanced also when residual renal function is abolished. In ESRD patients with urolithiasis, diagnosis of Hyperoxaluria should be ruled out before AVF placement.

Vitamin D Effects on Bone Homeostasis and Cardiovascular System in Patients with Chronic Kidney Disease and Renal Transplant Recipients

Poor vitamin D status is common in patients with impaired renal function and represents one main component of the complex scenario of chronic kidney disease-mineral and bone disorder (CKD-MBD). Therapeutic and dietary efforts to limit the consequences of uremia-associated vitamin D deficiency are a current hot topic for researchers and clinicians in the nephrology area. Evidence indicates that the low levels of vitamin D in patients with CKD stage above 4 (GFR < 15 mL/min) have a multifactorial origin, mainly related to uremic malnutrition, namely impaired gastrointestinal absorption, dietary restrictions (low-protein and low-phosphate diets), and proteinuria. This condition is further worsened by the compromised response of CKD patients to high-dose cholecalciferol supplementation due to the defective activation of renal hydroxylation of vitamin D. Currently, the literature lacks large and interventional studies on the so-called non-calcemic activities of vitamin D and, above all, the modulation of renal and cardiovascular functions and immune response. Here, we review the current state of the art of the benefits of supplementation with native vitamin D in various clinical settings of nephrological interest: CKD, dialysis, and renal transplant, with a special focus on the effects on bone homeostasis and cardiovascular outcomes.

COVID-19 pandemic era: is it time to promote home dialysis and peritoneal dialysis?

The novel coronavirus, called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was declared a pandemic in March 2020 by the World Health Organization. Older individuals and patients with comorbid conditions such as hypertension, heart disease, diabetes, lung disease, chronic kidney disease (CKD) and immunologic diseases are at higher risk of contracting this severe infection. In particular, patients with advanced CKD constitute a vulnerable population and a challenge in the prevention and control of the disease. Home-based renal replacement therapies offer an opportunity to manage patients remotely, thus reducing the likelihood of infection due to direct human interaction. Patients are seen less frequently, limiting the close interaction between patients and healthcare workers who may contract and spread the disease. However, while home dialysis is a reasonable choice at this time due to the advantage of isolation of patients, measures must be assured to implement the program. Despite its logistical benefits, outpatient haemodialysis also presents certain challenges during times of crises such as the coronavirus disease 2019 (COVID-19) pandemic and potentially future ones.

Biomarkers of Kidney Injury in Very-low-birth-weight Preterm Infants: Influence of Maternal and Neonatal Factors

BACKGROUND/AIM

Acute kidney injury is an important cause of mortality in very-low-birth-weight (VLBW) preterm infants. As in the general population, the detection of renal damage cannot rely on the measurement of serum creatinine, since it has been demonstrated to be a weak predictor and a delayed indicator of kidney function deterioration. However, several candidate biomarkers have failed to prove sufficient specificity and sensitivity for a routine clinical use because of the poor awareness of their biological role. This study was aimed to investigate the impact of different maternal and neonatal conditions on several renal biomarkers in VLBW preterm infants during the first week of life.

PATIENTS AND METHODS

Preterm infants<32 weeks' gestation and <1500g were enrolled. We measured urinary biomarkers kidney injury molecule 1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), cystatin C, epidermal growth factor (EGF) and osteopontin (OPN) on the 1^st, 3^rd, and 7^th day after birth.

RESULTS

Thirty-tree infants were included. The multivariate analysis showed a significant association between gestational age, the presence of patent ductus arteriosus, antenatal maternal hypertension and the levels of urinary biomarkers.

CONCLUSION

There is a possible relation between early biomarkers of renal injury and antenatal, perinatal and post-natal characteristics in VLBW preterm infants during the first week of life.

Deciphering the pathogenesis of the COL4-related hematuric nephritis: A genotype/phenotype study

Background

Alport syndrome (ATS) is a hereditary progressive hematuric nephropathy associated with sensorineural deafness and ocular abnormalities, which is caused by mutations in the COL4A5 gene (X‐linked ATS) and in two autosomal genes, COL4A4 and COL4A3, responsible of both recessive ATS and, when present in heterozygosity, of a spectrum of phenotypes ranging from isolated hematuria to frank renal disease.

Methods

Retrospective analysis of the clinical and genetic features of 76 patients from 34 unrelated ATS families (11 with mutations in COL4A5, 11 in COL4A3, and 12 in COL4A4) and genotype/phenotype correlation for the COL4A3/COL4A4 heterozygotes (34 patients from 14 families).

Results

Eight (24%) of the 34 heterozygous COL4A3 and COL4A4 carriers developed renal failure at a mean age of 57 years, with a significantly lower risk than hemizygous COL4A5 or double heterozygous COL4A3/COL4A4 carriers (p < 0.01), but not different from that of the heterozygous COL4A5 females (p = 0.6). Heterozygous carriers of frameshift/splicing variants in COL4A3/COL4A4 presented a higher risk of developing renal failure than those with missense variants in the glycine domains (p = 0.015).

Conclusion

The renal functional prognosis of patients with COL4A3/COL4A4‐positive ATS recapitulates that of the X‐linked ATS forms, with differences between heterozygous vs. double heterozygous patients and between carriers of loss‐of‐function vs. missense variants.

The role of activin: the other side of chronic kidney disease-mineral bone disorder?

Chronic kidney disease-mineral bone disorder (CKD-MBD) plays a pivotal role in the excess of cardiovascular morbidity and mortality associated with CKD. There is now a growing awareness that pathways involved in CKD-MBD, like canonical Wnt signalling, are activated from the earliest stages of CKD, playing a role in the development of adynamic bone disease with unknown consequences on vasculature. These changes occur before the classic changes in mineral metabolism: secondary hyperparathyroidism, calcitriol deficiency and hyperphosphataemia. Furthermore, vascular calcification is frequently associated and evolves with decreased bone mineral density and deranged bone turnover, while bone and arterial mineralization share common pathways. Therefore, results of clinical trials focused on mineral bone disorder, aimed at preserving bone and cardiovascular health, are considered unsatisfactory. In order to identify more effective therapeutic strategies, it is necessary to clarify the pathways modulating the cross-talk between bone and vasculature and identify new mediators involved in the pathogenesis of CKD-MBD. Much attention has been paid recently to the role of the transforming growth factor-beta superfamily members in renal disease, and in particular of activin A (ActA). Preclinical studies demonstrate an upgrade of ActA signalling in kidney, skeleton, vasculature and heart during CKD. This supports the idea that an endocrine factor produced in the kidney during renal disease, in addition to promoting the progression of kidney damage, deranges other organs' homoeostasis and participates in CKD-MBD. In this review, we analyse the contribution of ActA to kidney fibrosis and inflammation as well as its role in the development of CKD-MBD.

SGLT2 inhibitors, sodium and off-target effects: an overview

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a relatively new class of antidiabetic drugs that in addition to emerging as an effective antihyperglycemic treatment have been shown to improve, in several trials, both renal and cardiovascular outcomes. In consideration of the renal site of action and the associated osmotic diuresis, a negative sodium balance has been postulated during SGLT2i administration. Actually, sodium and water depletion may contribute to some positive actions of SGLT2i but evidence is far from being conclusive and the real physiologic effects of SGLT2i on sodium remain largely unknown. Indeed, no study has yet investigated how SGLT2i change sodium balance in the long term and especially the pathways through which the natriuretic effect is expressed. Furthermore, several experimental studies have recently identified different pathways, not directly linked to tubular sodium handling, which could contribute to the renal and cardiovascular benefits associated with SGLT2i. This paper will review the evidence of SGLT2i action on sodium transporters, their off-target effects and their potential role on kidney protection.

An international cohort study of autosomal dominant tubulointerstitial kidney disease due to REN mutations identifies distinct clinical subtypes

There have been few clinical or scientific reports of autosomal dominant tubulointerstitial kidney disease due to REN mutations (ADTKD-REN), limiting characterization. To further study this, we formed an international cohort characterizing 111 individuals from 30 families with both clinical and laboratory findings. Sixty-nine individuals had a REN mutation in the signal peptide region (signal group), 27 in the prosegment (prosegment group), and 15 in the mature renin peptide (mature group). Signal group patients were most severely affected, presenting at a mean age of 19.7 years, with the prosegment group presenting at 22.4 years, and the mature group at 37 years. Anemia was present in childhood in 91% in the signal group, 69% prosegment, and none of the mature group. REN signal peptide mutations reduced hydrophobicity of the signal peptide, which is necessary for recognition and translocation across the endoplasmic reticulum, leading to aberrant delivery of preprorenin into the cytoplasm. REN mutations in the prosegment led to deposition of prorenin and renin in the endoplasmic reticulum-Golgi intermediate compartment and decreased prorenin secretion. Mutations in mature renin led to deposition of the mutant prorenin in the endoplasmic reticulum, similar to patients with ADTKD-UMOD, with a rate of progression to end stage kidney disease (63.6 years) that was significantly slower vs. the signal (53.1 years) and prosegment groups (50.8 years) (significant hazard ratio 0.367). Thus, clinical and laboratory studies revealed subtypes of ADTKD-REN that are pathophysiologically, diagnostically, and clinically distinct.

The Off-Target Effects, Electrolyte and Mineral Disorders of SGLT2i

The sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a relatively new class of antidiabetic drugs that, in addition to emerging as an effective hypoglycemic treatment, have been shown to improve, in several trials, both renal and cardiovascular outcomes. In consideration of the renal site of action and the associated osmotic diuresis, a negative sodium balance has been postulated during SGLT2i administration. Although it is presumable that sodium and water depletion may contribute to some positive actions of SGLT2i, evidence is far from being conclusive and the real physiologic effects of SGLT2i on sodium remain largely unknown. Indeed, no study has yet investigated how SGLT2i change sodium balance in the long term and especially the pathways through which the natriuretic effect is expressed. Furthermore, recently, several experimental studies have identified different pathways, not directly linked to tubular sodium handling, which could contribute to the renal and cardiovascular benefits associated with SGLT2i. These compounds may also modulate urinary chloride, potassium, magnesium, phosphate, and calcium excretion. Some changes in electrolyte homeostasis are transient, whereas others may persist, suggesting that the administration of SGLT2i may affect mineral and electrolyte balances in exposed subjects. This paper will review the evidence of SGLT2i action on sodium transporters, their off-target effects and their potential role on kidney protection as well as their influence on electrolytes and mineral homeostasis.

P0085MAYO AND PRO-PKD SCORE CONCORDANCE FOR PROGRESSION OF RENAL FALIURE EVALUATION IN ADPKD PATIENTS

Background and Aims

Autosomal dominant polycystic kidney disease (ADPKD) is a multisystemic disease characterized by the progressive development of bilateral renal cysts, resulting in enlargement of the kidney volume due to cystic formations, hypertension, haematuria, and loss of renal function. Recent advances in genomics have contributed to have a better understanding of the pathogenesis of the disease suggesting new treatment strategies to inhibit or delay cysts formation and expansion.Since 2015, the European Medicines Agency approved Vaptans as therapy to slow the growth of kidney volume and the decline in kidney function in patients defined rapid progressors.

In 2016 European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Working Groups on Inherited Kidney Disorders and European Renal Best Practice (WGIKD/ ERBP) published a position statement for definition of rapid progression. These recommendations included two algorithms to assess indications for initiation of ADPKD treatment. They selected three criteria based on: 1) the relationship between TKV(total kidney volume) and the decline in renal function according CRISP study, using Mayo Clinic Score 2) eGFR slope with an average ≥2.5 mL/min/1.73 m2/ yearly loss of renal function over a period of 5 yearsor 3) the link between genetic mutation and clinical information study using Propkd score.A 5 –years follow-up is not always available to achieve the criteria for rapid progressor, therefore the use of scores in clinical practice is widespread.In this scenario both scores (MAYO and PRO-PKD) are able to define rapid progressor patients and it is possible to use them alternatively as reported in literature.

The aim of this study is to evaluate the prognostic scores in a real life experience.

Method

All ADPKD patients in follow-up in our Nephrology Unit from January 2017 to July 2019 were included in the study. Descriptive statistics were used to summarize demographic and clinical characteristics. Therefore we classified them for TKV, genetic mutation, renal function, Mayo score and Propkd score.

Rapid progression was defined as 1C-D-E Mayo and high risk PRO PKD while non rapid progressors was 1A-1B mayo and low and intermediate PRO-PKD. Kappa statistic was used to determinate the concordance between Mayo and PROPKD score. Change in renal function within patients with the same class of score where analysed using Paired Wilcoxon signed rank sum test.

Results

We examined75 patients, 78% between 18-50 years, equally distributed for sex. The results shown thatdisease was more frequent familiar (88 %) witha percentage of mutations of PKD1 versus PKD2 mutation (90,7%/9,3%). 31patients (41%) had a GFR between 45-89 ml/min, 52patients (69%) achieved the criteria for nephromegaly according guideline (TKV &gt; 750CC). Respectively 76% (57pt) and 21%(16pt) were defined as rapid progressors for Mayo score ad Propkd score.

The slope of GFR was worse in patients defined rapid progressor in spite of non rapidprogressor according MAYO score (-2,8 ml/min vs 0,3 ml/min) as for propkd classification (-3 vs - 1,75ml/min).

Only for 15 patients the results were concordant for this two scores,43 patients identified as rapid progressor for Mayo score were non rapid progressor for Propkd score, in the same way 2 patients classified for Propkd were not rapid progressor for Mayo score. K of Coen of 0,07.

Conclusion

High risk patients present a significant decline in renal function in the first year with both score systems, confirming results of previous studies. Currently the scores used to define rapid progressors select patients differently. Concordance between scores il low (K of Cohen 0,076). The Propkd score is more selective compared to Mayo score. NeverthelessProPKD allows to identify some rapid progressor patients excluded from the use of the Mayo score only. The combined use of scoring may however increases the ability to identify progressive patients.

Gene Panel Analysis in a Large Cohort of Patients With Autosomal Dominant Polycystic Kidney Disease Allows the Identification of 80 Potentially Causative Novel Variants and the Characterization of a Complex Genetic Architecture in a Subset of Families

Introduction: Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common inherited disorders in humans and the majority of patients carry a variant in either PKD1 or PKD2. Genetic testing is increasingly required for diagnosis, prognosis, and treatment decision, but it is challenging due to segmental duplications of PKD1, genetic and allelic heterogeneity, and the presence of many variants hypomorphic or of uncertain significance. We propose an NGS-based testing strategy for molecular analysis of ADPKD and its phenocopies, validated in a diagnostic setting. Materials and Methods: Our protocol is based on high-throughput simultaneous sequencing of PKD1 and PKD2 after long range PCR of coding regions, followed by a masked reference genome alignment, and MLPA analysis. A further screening of additional 14 cystogenes was performed in negative cases. We applied this strategy to analyze 212 patients with a clinical suspicion of ADPKD. Results and Discussion: We detected causative variants (interpreted as pathogenic/likely pathogenic) in 61.3% of our index patients, and variants of uncertain clinical significance in 12.5%. The majority (88%) of genetic variants was identified in PKD1, 12% in PKD2. Among 158 distinct variants, 80 (50.6%) were previously unreported, confirming broad allelic heterogeneity. Eleven patients showed more than one variant. Segregation analysis indicated biallelic disease in five patients, digenic in one, de novo variant with unknown phase in two. Furthermore, our NGS protocol allowed the identification of two patients with somatic mosaicism, which was undetectable with Sanger sequencing. Among patients without PKD1/PKD2 variants, we identified three with possible alternative diagnosis: a patient with biallelic mutations in PKHD1, confirming the overlap between recessive and dominant PKD, and two patients with variants in ALG8 and PRKCSH, respectively. Genotype-phenotype correlations showed that patients with PKD1 variants predicted to truncate (T) the protein experienced end-stage renal disease 9 years earlier than patients with PKD1 non-truncating (NT) mutations and >13 years earlier than patients with PKD2 mutations. ADPKD-PKD1 ^T cases showed a disease onset significantly earlier than ADPKD-PKD1 ^NT and ADPK-PKD2, as well as a significant earlier diagnosis. These data emphasize the need to combine clinical information with genetic data to achieve useful prognostic predictions.

A Pathogenic Galactosidase A Mutation Coexisting With an MYBPC3 Mutation in a Female Patient With Hypertrophic Cardiomyopathy

The coexistence of GLA (Pro259Ser, c.775C>T) and MYBPC3 (c.1351+2T>C) mutations was found in a female patient with hypertrophic cardiomyopathy. Histology documented abundant vacuolisation with osmiophilic lamellar bodies and positive Gb3 immunohistochemistry. In the presence of a hypertrophic cardiomyopathy phenotype, the systematic search for unusual findings is mandatory to rule out a phenocopy.

Iloprost in Acute Post-kidney Transplant Atheroembolism: A Case Report of Two Successful Treatments

Cholesterol embolization (CE) is a rare and alarming post-transplant complication, responsible for primary non-function (PNF) or delayed graft function (DGF). Its incidence is expected to rise due to increasingly old donors and recipients and the extended criteria for donation. Therapy with statins and steroids has not been shown to be effective, while agonism of prostaglandin I₂ has been reported to be useful in systemic CE. We report two cases of acute post-transplant CE in which intravenous iloprost (0.05 mg/kg/day) was added to standard statin and steroid therapy. In the first instance, CE was due to embolization from the kidney artery resulting in embolization of the small vessels; after a long DGF and 15 days of iloprost therapy, renal function recovered. The second instance is a case of embolization from the iliac artery of the recipient, where CE manifested as a partial renal infarction. After 5 days of iloprost administration, creatinine levels improved. Iloprost acts on vasodilation and on different inflammatory pathways, improving the anti-inflammatory profile. Post-transplant CE is difficult to diagnose and, if not treated, can lead to loss of function. Iloprost added to standard therapy could be beneficial in accelerating renal function recovery immediately after transplant.

Time evolution of restless legs syndrome in haemodialysis patients

Background

Restless legs syndrome (RLS) is characterized by an urge to move the extremities, accompanied by paraesthesiae, in the evening and at night. Uraemic RLS, a type of secondary RLS, occurs commonly in chronic kidney disease and end-stage renal disease. Progression of uraemic RLS over time is unclear. Therefore we investigated the prevalence, progression over time, risk factors and impact on survival of uraemic RLS in a cohort of dialysis patients.

Methods

We reviewed at the 7-year follow-up a cohort of haemodialysis (HD) patients we had previously investigated for RLS, through interviews, validated questionnaires and analysis of demographic and clinical data.

Results

At the 7-year follow-up, RLS was present in 16% of patients, with a persistence rate of 33%. A correlation was obtained between RLS and older age, diabetes, low albumin and low body mass index. RLS was associated with reduced overall survival (median survival of 3.3 versus 3.7 years), particularly with the continuous form of RLS (1.61 years). There was a higher incidence of myocardial infarction and peripheral vascular disease, although not reaching statistical significance. RLS patients had absolute higher scores in all quality of life domains. A large majority of study patients (96%) reported being symptom-free within a few days or weeks following kidney transplantation.

Conclusions

The development of RLS, especially the continuous form, in patients undergoing HD has important consequences associated with decreased survival. Our results indicated an association between uraemic RLS and ageing, diabetes and malnutrition. Considerable efforts should be focused on the treatment of RLS, since it significantly and persistently impacts the quality of life of HD patients. Kidney transplantation could represent an effective treatment option for that RLS impacts on dialysis patients' quality of life, thus confirming the secondary nature of RLS in most HD patients.

Non-marital Pregnancies and Unmarried Women's Search for Illegal Abortion in Morocco

Abortion in Morocco is illegal except to safeguard a woman's life or health. Morocco has put some sexual and reproductive health policies into motion that are in line with the standards defined by the World Health Organization and the United Nations Population Fund, especially after the 1994 International Conference on Population and Development, but Morocco's Penal Code continues to criminalize the practice. This paper explores how proposed reforms to the abortion law that on the surface seem to legalize abortion in cases of severe health disorders or rape in reality moralize abortion, since vulnerable women should prove these conditions through lengthy bureaucratic procedures. Drawing on ethnographic fieldwork on unplanned pregnancies, I examine the social and health inequalities surrounding illegal abortion. My results show that socioeconomic status, education, geography, and marital status all play a role in delineating which women are willing or able to obtain an abortion and under which conditions the abortion takes place. I use the concept of "reproductive governance" to examine the relevance of rights-based approaches in Morocco, ultimately arguing that the intersection of socioeconomic and political processes in the country normalizes the risk and occurrence of illegal abortion, particularly for unmarried women living in precarious socioeconomic conditions, who are not addressed by sexual and reproductive health policies.¹.

Nutritional vitamin D in CKD: Should we measure? Should we treat?

Vitamin Ddeficiency is frequently present in patients affected by chronic kidney disease (CKD). Experimental studies demonstrated that Vitamin D may play a role in the pathophysiology of diseases beyond mineral bone disorders in CKD (CKD-MBD). Unfortunately, the lack of large and interventional studies focused on the so called "non-classic" effects of 25(OH) Vitamin D supplementation in CKD patients, doesn't permit to conclude definitely about the beneficial effects of this supplementation in clinical practice. In conclusion, treatment of nutritional vitamin D deficiency in CKD may play a central role in both bone homeostasis and cardiovascular outcomes, but there is not clear evidence to support one formulation of nutritional vitamin D over another in CKD.

Mineral and Electrolyte Disorders With SGLT2i Therapy

The newly developed sodium‐glucose cotransporter 2 inhibitors (SGLT2is) effectively modulate glucose metabolism in diabetes. Although clinical data suggest that SGLT2is (empagliflozin, dapagliflozin, ertugliflozin, canagliflozin, ipragliflozin) are safe and protect against renal and cardiovascular events, very little attention has been dedicated to the effects of these compounds on different electrolytes. As with other antidiabetic compounds, some effects on water and electrolytes balance have been documented. Although the natriuretic effect and osmotic diuresis are expected with SGLT2is, these compounds may also modulate urinary potassium, magnesium, phosphate, and calcium excretion. Notably, they have had no effect on plasma sodium levels and promoted only small increases in serum potassium and magnesium concentrations in clinical trials. Moreover, SGLT2is may induce an increase in serum phosphate, FGF‐23, and PTH; reduce 1,25‐dihydroxyvitamin D; and generate normal serum calcium. Some published and preliminary reports, as well as unconfirmed reports have suggested an association with bone fractures. Some homeostasis perturbations are transient, whereas others may persist, suggesting that the administration of SGLT2is may affect electrolyte balances in exposed subjects. Although current evidence supports their safety, additional efforts are needed to elucidate the long‐term impact of these compounds on chronic kidney disease, mineral metabolism, and bone health. Indeed, the limited follow‐up studies and the heterogeneity of the case‐mix of different randomized controlled trials preclude a definitive answer on the impact of these compounds on long‐term outcomes such as the risk of bone fracture. Here we review the current understanding of the mechanisms involved in electrolyte handling and the available data on the clinical implications of electrolytes and mineral metabolism perturbations induced by SGLT2i administration. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Correlation Between Renal Cortical Stiffness and Histological Determinants by Point Shear-Wave Elastography in Patients With Kidney Transplantation

INTRODUCTION

Renal allograft biopsy is the gold standard for the detection of histological lesions of chronic allograft dysfunction. The identification of a noninvasive routine test would be desirable. Elastosonography is used to assess tissue stiffness according to viscosity, and no data are available on the use of point quantification shear-wave elastography (ElastPQ) for the evaluation of renal chronic lesions.

RESEARCH QUESTION

To evaluate the feasibility of ElastPQ to assess cortical allograft stiffness and to determine the correlation of clinical, biological, and pathological factors with the diagnostic accuracy of kidney stiffness values in patients with histological lesions.

DESIGN

Forty-two patients underwent kidney transplant biopsy and 10 valid measurements of ElastPQ, blindly performed by 2 operators. The interobserver reproducibility was assessed according to intraclass correlation coefficient. The ElastPQ measurements and the clinical data were compared using the Spearman correlation analysis.

RESULTS

97.6% reliable measurements were obtained using ElastPQ, with an excellent interobserver agreement. The kidney stiffness was significantly higher in the patients with a time since transplantation >12 months and was correlated with chronic lesions (interstitial fibrosis, tubular atrophy transplant glomerulopathy, and mesangial matrix), with the interstitial fibrosis/tubular atrophy, score and with the sum of the scores of the chronic lesions. Mesangial matrix increase is the only independent determinant of kidney stiffness.

DISCUSSION

ElastPQ is a noninvasive, reproducible, and sensitive diagnostic tool able to detect moderate/severe chronic lesions. Its routine use during follow-up can identify patients eligible for biopsy, which remains the gold standard exam for detecting chronic allograft dysfunction.

Histological Evidence of Diabetic Kidney Disease Precede Clinical Diagnosis

BACKGROUND

In the absence of a histological diagnosis, persistent albuminuria is globally accepted as the main diagnostic criteria for diabetic kidney disease (DKD).

METHODS

In the present retrospective study, we evaluated data from an Italian cohort of 42 deceased diabetic donors (mainly with type 2 diabetes). Using the kidney biopsies obtained at the time of donation to evaluate single or double allocation based on Karpinski score, we determined the prevalence of histological lesions attributable to diabetes.

RESULTS

All 42 donors presented with proteinuria in the normal range and an estimated glomerular filtration rate (eGFR) (chronic kidney disease [CKD]-EPI) >60 mL/min/1.73 m2. A kidney biopsy was available for 36 patients; of these, one was not interpretable and 32 showed histopathological lesions consistent with DKD and encompassing all histological classes. Thus, we found a relatively high proportion of histologically proven DKD that had been clinically undiagnosed, as none of the patient had significant proteinuria and eGFR <60 mL/min/1.73 m2.

CONCLUSIONS

The data we present here support the need to implement routine kidney biopsies in normoalbuminuric diabetic subjects in the early stages of CKD. Such strategy may help to improve risk stratification in diabetic patients and guide therapeutic decisions during the early stages of the disease.

New mineralocorticoid receptor antagonists: update on their use in chronic kidney disease and heart failure

Aldosterone is a mineralocorticoid hormone with a well-known effect on the renal tubule leading to water retention and potassium reabsorption. Other major effects of the hormone include the induction of proinflammatory activity that leads to progressive fibrotic damage of the target organs, heart and kidney. Blocking the aldosterone receptor therefore represents an important pharmacological strategy to avoid the clinical conditions deriving from heart failure (CHF) and chronic kidney disease (CKD). However, steroidal mineralocorticoid receptor antagonists (MRA) have a low safety profile, especially in CKD patients due to the high incidence of hyperkalemia. A new generation of nonsteroidal MRA has recently been developed to obtain a selective receptor block avoiding side-effects like hyperkalemia and thereby making the drugs suitable for administration to CKD patients. This review summarizes the results of published preclinical and clinical studies on the nonsteroidal MRA, apararenone esaxerenone and finerenone. The trials showed a better safety profile with maintained drug efficacy compared with steroidal MRA. For this reason, nonsteroidal MRA represent an interesting new therapeutic approach for the prevention of CHF and CKD progression. Some basic research findings also yielded interesting results in acute clinical settings such as myocardial infarction and acute kidney injury.

The Key Role of Phosphate on Vascular Calcification

Vascular calcification (VC) is common in dialysis and non-dialysis chronic kidney disease (CKD) patients, even in the early stage of the disease. For this reason, it can be considered a CKD hallmark. VC contributes to cardiovascular disease (CVD) and increased mortality among CKD patients, although it has not been proven. There are more than one type of VC and every form represents a marker of systemic vascular disease and is associated with a higher prevalence of CVD in CKD patients, as shown by several clinical studies. Major risk factors for VC in CKD include: Increasing age, dialysis vintage, hyperphosphatemia (particularly in the setting of intermittent or persistent hypercalcemia), and a positive net calcium and phosphate balance. Excessive oral calcium intake, including calcium-containing phosphate binders, increases the risk for VC. Moreover, it has been demonstrated that there is less VC progression with non-calcium-containing phosphate binders. Unfortunately, until now, a specific therapy to prevent progression or to facilitate regression of VC has been found, beyond careful attention to calcium and phosphate balance.

Folic Acid and Vitamin B12 Administration in CKD, Why Not?

Patients affected by chronic kidney disease (CKD) or end-stage renal disease (ESRD) experience a huge cardiovascular risk and cardiovascular events represent the leading causes of death. Since traditional risk factors cannot fully explain such increased cardiovascular risk, interest in non-traditional risk factors, such as hyperhomocysteinemia and folic acid and vitamin B12 metabolism impairment, is growing. Although elevated homocysteine blood levels are often seen in patients with CKD and ESRD, whether hyperhomocysteinemia represents a reliable cardiovascular and mortality risk marker or a therapeutic target in this population is still unclear. In addition, folic acid and vitamin B12 could not only be mere cofactors in the homocysteine metabolism; they may have a direct action in determining tissue damage and cardiovascular risk. The purpose of this review was to highlight homocysteine, folic acid and vitamin B12 metabolism impairment in CKD and ESRD and to summarize available evidences on hyperhomocysteinemia, folic acid and vitamin B12 as cardiovascular risk markers, therapeutic target and risk factors for CKD progression.

Klotho-FGF23, Cardiovascular Disease, and Vascular Calcification: Black or White?

BACKGROUND

Patients affected by Chronic Kidney Disease and Mineral Bone Disorder (CKD-MBD) have a high risk of cardiovascular (CV) mortality that is poorly explained by traditional risk factors. The newest medical treatments for CKD-MBD have been associated with encouraging, but still inconsistent, improvement in CV disease complications and patient survival. A better understanding of the biomarkers and mechanisms of left ventricular hypertrophy (LVH), atherosclerosis, and vascular calcification (VC) may help with diagnosis and treatment of the organ damage that occurs secondary to CKD-MBD, thus improving survival. Recent insights about fibroblast growth factor-23 (FGF23) and its co-receptor, Klotho, have led to marked advancement in interpreting data on vascular aging and CKDMBD.

CONCLUSION

This review will discuss the current experimental and clinical evidence regarding FGF23 and Klotho, with a particular focus on their roles in LVH, atherosclerosis, and VC.

Impact of 3 Major Maintenance Immunosuppressive Protocols on Long-term Clinical Outcomes: Result of a Large Multicenter Italian Cohort Study Including 5635 Renal Transplant Recipients

BACKGROUND

Although optimization of immunosuppressive schemes in renal transplantation have minimized acute posttransplant complications, long-term outcomes are still not optimal and most of the chronic graft damage is drug-related. Therefore, to define the best long-term maintenance immunosuppressive regimen is of major importance in renal transplantation. To assess this objective, we undertook a large, multicenter cohort study in Italy.

METHODS

We retrospectively analyzed data of 5635 patients (enrolled from 1983 to 2012) and we assessed the impact of 3 major immunosuppressive regimens (calcineurin inhibitors+antimetabolites+corticosteroids [CNI+ANT+CS] vs CNI+mammalian target-of-rapamycin (mTOR) inhibitors+CS [CNI+mTOR-I+CS] vs CNI+CS) on long-term clinical outcomes by employing several statistical algorithms.

RESULTS

The overall difference in the incidence of outcome over time was not statistically different within the first 5 years of follow-up (P = .13); however, it became significant at 10 years and 20 years (P < .01), with the CNI+CS group showing the lowest cumulative incidence of outcome. Compared with the CNI+ANT+CS group, the CNI+mTOR-I+CS group patients had a significantly higher risk of outcome (hazard ratio [HR], 1.30; P = .024); the difference remained significant and even increased in magnitude after adjustment for potential confounders (HR, 1.38; P = .006). Similarly, patients in the CNI+CS group had a significantly higher risk of the outcome (HR, 1.64; P < .001).

CONCLUSION

Our data confirm that CNI+ANT+CS is the "gold standard" therapy in renal transplantation, but, whenever required, the introduction of mTOR-Is instead of ANT may not dramatically modify major clinical outcomes. The use of mTOR-I could be a valuable pharmacologic tool to minimize CNI complications and insure adequate immunosuppression.

Increase in Serum Amylase and Resistive Index After Kidney Transplant Are Biomarkers of Delayed Graft Function

BACKGROUND

Both amylase and resistive index (RI) are routinely measured after kidney transplant and proposed as markers of delayed graft function (DGF).

MATERIAL AND METHODS

This retrospective cross-sectional study analyzed amylase and RI in 269 renal transplant recipients before and after transplantation, and at discharge. An increase above 20% of total amylase with/without RI>0.7 were evaluated as prognostic markers of DGF, hospitalization length and risk of rejection.

RESULTS

Serum amylase increase >20% was found in 103/269 (38.3%) patients who showed DGF (45.6% vs. 25.3%, p=0.001) and had lower estimated glomerular filtration rate compared to those with an amylase increase <20% (42.0±21.7 vs. 49.8±23.2 ml/min, p=0.007). The double condition consisting of concomitant amylase increase >20% and RI>0.7 was associated with higher DGF occurrence (65% vs. 24%, p<0.001), longer hospital stay, lower eGFR at discharge, and higher risk of rejection.

CONCLUSION

Patients with concomitant amylase increase >20% and RI>0.7 might require closer monitoring to diagnose DGF early and modify the therapeutic approach accordingly.

Functional Abnormalities and Thyroid Nodules in Patients with End-stage Renal Disease

BACKGROUND/AIM

Clinical and subclinical hypothyroidism is more common in patients with end-stage renal disease (ESRD) than in the general population. Patients with ESRD with hypothyroidism are more susceptible to cardiovascular disease, with an increased risk of mortality than those with normal thyroid function. Moreover, these patients have higher incidence of benign and malignant nodules.

PATIENTS AND METHODS

This was a retrospective study on 2,147 patients with ESRD on the renal transplant waiting list between 2000 and 2015 aimed at identifying the presence of hypothyroidism and associated variables.

RESULTS

Hypothyroidism was detected in 437/2,147 (20.3%) patients, 289 of them having the subclinical form. Cardiovascular disease and older age were significantly associated with hypothyroidism, and autosomal polycystic kidney disease was correlated to goiter (p<0.001).

CONCLUSION

Thyroid abnormalities, particularly hypothyroidism with nodules, should be investigated in patients with ESRD on a waiting list for renal transplant to control cardiovascular complications and cancer risk.

Atrial changes after kidney transplant: what diagnostic and therapeutic perspectives?

Kidney transplant is known to be the first choice therapy for end stage chronic kidney disease, also for its positive effects on kidney transplant recipients cardiovascular morbidity and mortality. Several evidences evaluated the morphological changes of the left ventricle before and after transplantation, demonstrating a positive effect of at least partial regression of left ventricular hypertrophy (LVH) in kidney transplant recipients. This article is protected by copyright. All rights reserved.

Neutrophil Gelatinase-Associated Lipocalin as a Biomarker of Allograft Function After Renal Transplantation: Evaluation of the Current Status and Future Insights

Neutrophil gelatinase‐associated lipocalin (NGAL), a protein belonging to the lipocalin superfamily initially found in activated neutrophils, is expressed by several cell types, including kidney tubule. The increase in NGAL production and release from tubular cells in response to various insults has been proven to predict acute kidney injury (AKI). For this reason, it has emerged as a valuable noninvasive biomarker of AKI in clinical nephrology. Also in the renal transplant setting, different studies have indicated NGAL as a valuable tool, especially in the early postoperative period, since the currently available clinical and laboratory parameters remain poorly sensitive to monitor immediate posttransplant graft function. This is an analysis of the recent literature to assess the utility of plasma and urinary NGAL, exosomal mRNA for NGAL, and NGAL levels in the perfusate of machine‐perfused kidneys for the prediction of graft function recovery in the early postsurgery phase after renal transplantation. We found that NGAL appears as a promising troponin‐like biomarker to detect short‐term impairment of graft function after renal transplant, but there are still some limitations in its clinical application, essentially related to its low specificity. Moreover, comparing NGAL assayed in serum, urine, machine‐perfusate, or as exosomal mRNA, each one has shown limitations and benefits in terms of predictive performance for DGF, according to various existing studies, feasibly due to different cut‐off levels, designs and patient sample sizes.

Sodium Prescription in the Prevention of Intradialytic Hypotension: New Insights into an Old Concept

Background: Sodium prescription in patients with intradialytic hypotension remains a challenge for the attending nephrologist, as it increases dialysate conductivity in hypotension-prone patients, thereby adding to dietary sodium levels. Methods: New sodium prescription strategies are now available, including the use of a mathematical model to compute the sodium mass to be removed during dialysis as a physiological controller. Results: This review describes the sodium load of patients with end-stage renal disease on chronic hemodialysis (HD) and discusses 2 strategies to remove excess sodium in patients prone to intradialytic hypotension, namely, Profiled HD and the hemodiafiltration Aequilibrium System. Conclusion: The Profiled HD and Aequilibrium System trial both proved effective in counteracting intradialytic hypotension.

Fifteen-Year Analysis of Deceased Kidney Donation: A Single Transplant Center Experience in a Region of Northern Italy

Background

The rising number of patients on waiting lists for kidney transplant and the shortage of available organs has intensified efforts to increase the number of potential donors.

Material/Methods

This study investigated changes in clinical parameters among potential deceased donors in the 15-year period between 1999 and 2013 and their impact on transplantation procedure and outcomes. A total of 1634 potential deceased donors were examined and divided into 2 groups: 707 of them identified from 1999 to 2005 (Group A), and 927 from 2006 to 2013 (Group B).

Results

The comparison between the potential donors in Group A vs. Group B revealed an increase over time in donor age (54.6±17.2 vs. 58.8±16.3, p<0.001), a reduction in the percentage of standard donors (52.3% vs. 39.8%, p<0.001), a broader utilization of organs from expanded criteria donors, and a greater number of comorbidities, particularly cardiovascular disease and dyslipidemia. However, renal function parameters and the bioptic scores did not change significantly over the years.

Conclusions

These results suggest the usefulness of strategies to increase the number of potential donors suitable for organ donation, especially among elderly and marginal donors.