Recognition patterns of acute kidney injury in hospitalized patients.

Background: Acute kidney injury (AKI) during hospitalization is associated with increased complications and mortality. Despite efforts to standardize AKI management, its recognition in clinical practice is limited. Methods: To assess and characterize different patterns of AKI diagnosis, we collected clinical data, serum creatinine (sCr) levels, comorbidities and outcomes from adult patients using the Hospital Discharge Form (HDF). AKI diagnosis was based on administrative data and according to Kidney Disease: Improving Global Outcomes (KDIGO) criteria by evaluating sCr variations during hospitalization. Additionally, patients were categorized based on the timing of AKI onset. Results: Among 56 820 patients, 42 900 (75.5%) had no AKI, 1893 (3.3%) had AKI diagnosed by sCr changes and coded in the HDF (full-AKI), 2529 (4.4%) had AKI reported on the HDF but not meeting sCr-based criteria (HDF-AKI) and 9498 (16.7%) had undetected AKI diagnosed by sCr changes but not coded in the HDF (KDIGO-AKI). Overall, AKI incidence was 24.5%, with a 68% undetection rate. Patients with KDIGO-AKI were younger and had a higher proportion of females, lower comorbidity burden, milder AKI stages, more frequent admissions to surgical wards and lower mortality compared with full-AKI patients. All AKI groups had worse outcomes than those without AKI, and AKI, even if undetected, was independently associated with mortality risk. Patients with AKI at admission had different profiles and better outcomes than those developing AKI later. Conclusions: AKI recognition in hospitalized patients is highly heterogeneous, with a significant prevalence of undetection. This variability may be affected by patients' characteristics, AKI-related factors, diagnostic approaches and in-hospital patient management. AKI remains a major risk factor, emphasizing the importance of ensuring proper diagnosis for all patients.

High-volume hemofiltration does not protect human kidney endothelial and tubular epithelial cells from septic plasma-induced injury.

High volume hemofiltration (HVHF) could remove from plasma inflammatory mediators involved in sepsis-associated acute kidney injury (SA-AKI). The IVOIRE trial did not show improvements of outcome and organ dysfunction using HVHF. The aim of this study was to evaluate in vitro the biological effects of plasma of patients treated by HVHF or standard volume hemofiltration (SVHF). We evaluated leukocyte adhesion, apoptosis and functional alterations of endothelial cells (EC) and tubular epithelial cells (TEC). In vitro data were correlated with plasma levels of TNF-α, Fas-Ligand (FasL), CD40-Ligand (CD40L), von Willebrand Factor (vWF) and endothelial-derived microparticles. An experimental model of in vitro hemofiltration using LPS-activated blood was established to assess cytokine mass adsorption during HVHF or SVHF. Plasma concentrations of TNF-ɑ, FasL, CD40L and von Willebrand Factor (vWF) were elevated at the start (d1h0) of both HVHF and SVHF, significantly decreased after 6 h (d1h6), remained stable after 12 h (d1h12) and then newly increased at 48 h (d3h0). Plasma levels of all these molecules were similar between HVHF- and SVHF-treated patients at all time points considered. In addition, the levels of endothelial microparticles remained always elevated, suggesting the presence of a persistent microvascular injury. Plasma from septic patients induced leukocyte adhesion on EC and TEC through up-regulation of adhesion receptors. Moreover, on EC, septic plasma induced a cytotoxic and anti-angiogenic effect. On TEC, septic plasma exerted a direct pro-apoptotic effect via Fas up-regulation and caspase activation, loss of polarity, altered expression of megalin and tight junction molecules with an impaired ability to internalize albumin. The inhibition of plasma-induced cell injury was concomitant to the decrease of TNF-α, Fas-Ligand and CD40-Ligand levels. The protective effect of both HVHF and SVHF was time-limited, since a further increase of circulating mediators and plasma-induced cell injury was observed after 48 h (d3h0). No significant difference of EC/TEC damage were observed using HVHF- or SVHF-treated plasma. The in vitro hemofiltration model confirmed the absence of a significant modulation of cytokine adsorption between HVHF and SVHF. In comparison to SVHF, HVHF did not increase inflammatory cytokine clearance and did not reverse the detrimental effects of septic plasma-induced EC and TEC injury. Further studies using adsorptive membranes are needed to evaluate the potential role of high dose convective therapies in the limitation of the harmful activity of plasma soluble factors involved in SA-AKI.Trial registration IVOIRE randomized clinical trial; ClinicalTrials.gov (NCT00241228) (18/10/2005).

Clinical and Economic Impact of Early Diagnosis of Chronic Kidney Disease in General Practice: The Endorse Study.

Introduction: The underdiagnosis of chronic kidney disease (CKD) remains a significant public health concern. The Early chroNic kiDney disease pOint of caRe Screening (ENDORSE) project aimed to evaluate the clinical and economic implications of a targeted training intervention for general practitioners (GPs) to enhance CKD awareness and early diagnosis. Methods: Data on estimated Glomerular Filtration Rate (eGFR) and Urinary Albumin-Creatinine Ratio (uACR) were collected by 53 Italian GPs from 112,178 patients at baseline and after six months. The intervention involved six months of hybrid training provided by 11 nephrologists, which included formal lectures, instant messaging support, and joint visits for complex cases. Results: The results demonstrated a substantial increase in the use of eGFR (+44.7%) and uACR (+95.2%) tests. This led to a 128.9% rise in the number of individuals screened for CKD using the KDIGO classification, resulting in a 62% increase in CKD diagnoses. The intervention's impact was particularly notable in high-risk groups, including patients with type 2 diabetes, hypertension, and heart failure. Discussion: A budget impact analysis projected cumulative five-year savings of €1.7 million for the study cohort. When these findings were extrapolated to the entire Italian CKD population, potential savings were estimated at €106.6 million, highlighting significant cost savings for the national health service. The clinical simulation assumed that early diagnosed CKD patients would be treated according to current indications for dapagliflozin, which slows disease progression. Conclusion: The ENDORSE model demonstrated that targeted training for GPs can significantly improve early CKD detection, leading to better patient outcomes and considerable economic benefits. This approach shows promise for broader implementation to address the underdiagnosis of CKD on a national and potentially international scale.

What Not to Overlook in the Management of Patients with Type 2 Diabetes Mellitus: The Nephrological and Hepatological Perspectives.

Diabetes mellitus (DM) significantly impacts renal and hepatic function, necessitating comprehensive understanding and management strategies. Renal involvement, namely diabetic kidney disease (DKD), presents a global challenge, with increasing prevalence paralleling DM rates. Lifestyle modifications and pharmacotherapy targeting hypertension and glycemic control have pivotal roles in DKD management. Concurrently, hepatic involvement in DM, characterized by metabolic dysfunction-associated steatotic liver disease (MASLD), presents a bidirectional relationship. DM exacerbates MASLD progression, while MASLD predisposes to DM development and worsens glycemic control. Screening for MASLD in DM patients is of high importance, utilizing non-invasive methods like ultrasound and fibrosis scores. Lifestyle modifications, such as weight loss and a Mediterranean diet, mitigate MASLD progression. Promising pharmacotherapies, like SGLT2 inhibitors and GLP-1 agonists, demonstrate efficacy in both DM and MASLD management. Special populations, such as diabetic individuals undergoing hemodialysis or kidney transplant recipients, demand special care due to unique clinical features. Similarly, DM exacerbates complications in MASLD patients, elevating the risks of hepatic decompensation and hepatocellular carcinoma. Recognizing the interconnectedness of DM, renal, and hepatic diseases underscores the need for multidisciplinary approaches for optimal patient outcomes. The present review aims to present the main characteristics and crucial points not to be overlooked regarding the renal and hepatic involvement in DM patients focusing on the inter-relationships between the renal and the hepatic involvements.

Associations of Intact and C-Terminal FGF23 with Inflammatory Markers in Older Patients Affected by Advanced Chronic Kidney Disease.

Background: In patients with chronic kidney disease (CKD), Fibroblast Growth Factor 23 (FGF23) is markedly increased and has been proposed to interact with systemic inflammation. Methods: In this cross-sectional study, we evaluated the correlations of intact FGF23, c-terminal FGF23, and the FGF23 ratio (c-terminal to intact) with some inflammatory cytokines in 111 elderly patients with advanced CKD not yet in dialysis. Results: Estimated glomerular filtration rate (eGFR) was inversely correlated with intact FGF23 and c-terminal FGF23, as well as with interleukin 6 (IL-6), tumor necrosis factor alpha (TNFα), and monocyte chemoattractant protein-1 (MCP-1). Intact FGF23 levels were directly correlated with IL-6 (r = 0.403; p < 0.001) and TNFα (r = 0.401; p < 0.001) while c-terminal FGF23 was directly correlated with MCP-1 (r = 0.264; p = 0.005). The FGF23 ratio was, instead, inversely correlated with IL-6 (r = -0.326; p < 0.001). Multivariate analysis revealed that intact FGF23 was directly associated with TNFα [B = 0.012 (95% CI 0.006, 0.019); p = 0.003] and c-terminal FGF23 was directly associated with MCP-1 [B = 0.001 (95% CI 0.000, 0.002); p = 0.038], while the FGF23 ratio was inversely correlated with IL-6 [B = -0.028 (95% CI -0.047, -0.010); p = 0.002]. Conclusions: Our data demonstrate that, in CKD patients, intact FGF23 and the metabolites deriving from its proteolytic cleavage are differently associated with some inflammatory pathways. In particular, intact FGF23 is mainly associated with IL-6 and TNFα, c-terminal FGF23 with MCP-1, and the FGF23 ratio with IL6.

Kidney transplantation in patients with ANCA-associated vasculitis is associated with a high incidence of post-transplant cancer.

BACKGROUND: Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a rare disease with limited data on outcomes after transplantation. METHODS: In this single-center retrospective cohort study, we describe the outcomes of kidney transplant patients with AAV transplanted at our institute from February 2006 to January 2022. RESULTS: We identified 9 patients among 1026 with a pre-transplant diagnosis of AAV; all patients had received previous treatment with cyclophosphamide. Maintenance immunosuppression after transplantation was tacrolimus-based in 89% of the patients. At the end of a mean follow-up of 132 ± 61.1 months after transplantation, only one case of extrarenal vasculitis relapse was observed. The relapse rate was 0.01 per patient per year, which is comparable to that reported in the literature. However, seven patients were diagnosed with cancer after a mean follow-up of 81.4 months after transplantation; six had skin cancer and three had renal cell carcinoma (RCC) of the native kidneys (cumulative incidence of 78%). One patient died from metastatic squamous cell carcinoma. CONCLUSION: In this study, we found a noticeable decrease in disease relapse (1 relapse in the present cohort vs 7 relapses in 19 patients in the previous cohort) in kidney transplant patients with AAV compared with previous data from our group (December 1987-January 2006). Conversely, we found a high incidence of post-transplant cancer. This result could be attributed to reduced immunosurveillance due to immunosuppression therapy before and after transplantation. Therefore, constant cancer early diagnosis and prevention is mandatory during the post-transplant follow-up of AAV patients.

Targeted silencing of GNAS in a human model of osteoprogenitor cells results in the deregulation of the osteogenic differentiation program.

Introduction: The dysregulation of cell fate toward osteoprecursor cells associated with most GNAS-based disorders may lead to episodic de novo extraskeletal or ectopic bone formation in subcutaneous tissues. The bony lesion distribution suggests the involvement of abnormal differentiation of mesenchymal stem cells (MSCs) and/or more committed precursor cells. Data from transgenic mice support the concept that GNAS is a crucial factor in regulating lineage switching between osteoblasts (OBs) and adipocyte fates. The mosaic nature of heterotopic bone lesions suggests that GNAS genetic defects provide a sensitized background for ectopic osteodifferentiation, but the underlying molecular mechanism remains largely unknown. Methods: The effect of GNAS silencing in the presence and/or absence of osteoblastic stimuli was evaluated in the human L88/5 MSC line during osteodifferentiation. A comparison of the data obtained with data coming from a bony lesion from a GNAS-mutated patient was also provided. Results: Our study adds some dowels to the current fragmented notions about the role of GNAS during osteoblastic differentiation, such as the premature transition of immature OBs into osteocytes and the characterization of the differences in the deposed bone matrix. Conclusion: We demonstrated that our cell model partially replicates the in vivo behavior results, resulting in an applicable human model to elucidate the pathophysiology of ectopic bone formation in GNAS-based disorders.

Glucagon-like peptide 1 receptor is a T cell-negative costimulatory molecule.

Glucagon-like peptide-1 receptor (GLP-1R) is a key regulator of glucose metabolism known to be expressed by pancreatic ß cells. We herein investigated the role of GLP-1R on T lymphocytes during immune response. Our data showed that a subset of T lymphocytes expresses GLP-1R, which is upregulated during alloimmune response, similarly to PD-1. When mice received islet or cardiac allotransplantation, an expansion of GLP-1Rpos T cells occurred in the spleen and was found to infiltrate the graft. Additional single-cell RNA sequencing (scRNA-seq) analysis conducted on GLP-1Rpos and GLP-1Rneg CD3+ T cells unveiled the existence of molecular and functional dissimilarities between both subpopulations, as the GLP-1Rpos are mainly composed of exhausted CD8 T cells. GLP-1R acts as a T cell-negative costimulatory molecule, and GLP-1R signaling prolongs allograft survival, mitigates alloimmune response, and reduces T lymphocyte graft infiltration. Notably, GLP-1R antagonism triggered anti-tumor immunity when tested in a preclinical mouse model of colorectal cancer.

Brain-Derived Neurotrophic Factor-Loaded Low-Temperature-Sensitive liposomes as a drug delivery system for repairing podocyte damage.

Podocytes, cells of the glomerular filtration barrier, play a crucial role in kidney diseases and are gaining attention as potential targets for new therapies. Brain-Derived Neurotrophic Factor (BDNF) has shown promising results in repairing podocyte damage, but its efficacy via parenteral administration is limited by a short half-life. Low temperature sensitive liposomes (LTSL) are a promising tool for targeted BDNF delivery, preserving its activity after encapsulation. This study aimed to improve LTSL design for efficient BDNF encapsulation and targeted release to podocytes, while maintaining stability and biological activity, and exploiting the conjugation of targeting peptides. While cyclic RGD (cRGD) was used for targeting endothelial cells in vitro, a homing peptide (HITSLLS) was conjugated for more specific uptake by glomerular endothelial cells in vivo. BDNF-loaded LTSL successfully repaired cytoskeleton damage in podocytes and reduced albumin permeability in a glomerular co-culture model. cRGD conjugation enhanced endothelial cell targeting and uptake, highlighting an improved therapeutic effect when BDNF release was induced by thermoresponsive liposomal degradation. In vivo, targeted LTSL showed evidence of accumulation in the kidneys, and their BDNF delivery decreased proteinuria and ameliorated kidney histology. These findings highlight the potential of BDNF-LTSL formulations in restoring podocyte function and treating glomerular diseases.

Peritoneal dialysis related peritonitis: insights from a long-term analysis of an Italian center.

BACKGROUND: Peritonitis is a common and severe complication of peritoneal dialysis (PD). For comparative analysis standardized definitions as well as measurements and outcomes are crucial. However, most PD-related peritonitis studies have been using heterogenous definitions and variable methods to measure outcomes. The ISPD 2022 guidelines have revised and clarified numerous definitions and proposed new peritonitis categories and outcomes. METHODS: Between 1st January 2009 and 31st May 2023, 267 patients who started PD at our institution were included in the study. All PD-related peritonitis episodes that occurred in our unit during the study period were collected. The new definitions and outcomes of ISPD 2022 recommendations were employed. RESULTS: The overall peritonitis rate was 0.25 episode/patient year. Patient cumulative probability of remaining peritonitis-free at one year was 84.2%. The medical cure and refractory peritonitis rates were equal to 70.3 and 22.4%, respectively. Culture-negative peritonitis accounted for 25.6% of all specimens. The rates of peritonitis associated death, hemodialysis transfer, catheter removal and hospitalization were 6.8%, 18.3%, 18.7% and 64.4%, respectively. Relapsing, repeat, recurrent and enteric peritonitis accounted for 7.8%, 6.8%, 4.1% and 2.7% of all episodes, respectively. Catheter insertion, catheter related and pre-PD peritonitis were 4.2, 2.1 and 0.5%. CONCLUSIONS: The implementation of PD-related peritonitis reports using standardized definitions and outcome measurements is of paramount importance to enhance clinical practice and to allow comparative studies.

Post-Transplant Diabetes Mellitus in Kidney-Transplanted Patients: Related Factors and Impact on Long-Term Outcome.

This study aimed to investigate the prevalence and determinants of glucose metabolism abnormalities and their impact on long-term clinical outcomes in kidney transplant recipients (KTxps). A retrospective analysis of 832 KTxps (2004-2020) was performed. Patients were assessed at 1 (T1), 6 (T6), and 12 (T12) months post-transplantation and clinically followed for an average of 103 ± 60 months. At T6, 484 patients underwent an oral glucose tolerance test for the diagnosis of alterations in glucose metabolism (AMG+) or post-transplant diabetes mellitus (PTDM+). The prevalence of pre-transplant diabetes was 6.2%, with 22.4% of PTDM+ within the 1st year. Patients with AMG were older and exhibited altered lipid profiles, higher body mass index, and increased inflammatory indices. Age at transplantation, lipid profile, and inflammatory status were significant determinants of PTDM. Graft loss was unaffected by glucose metabolism alterations. Survival analysis demonstrated significantly worse long-term survival for KTxps with diabetes (pre- and PTDM+, p = 0.04). In a comparison of the ND and PTDM+ groups, no significant differences in death with a functioning graft were found. The AMG+ group exhibited worse survival (p < 0.001) than AMG-, even after excluding patients with diabetes mellitus. Future randomized controlled trials are necessary to delve deeper into this subject, specifically examining the effects of new antidiabetic treatments.

PMMA dialyzers modulate both humoral and cell-mediate immune response to anti-COVID-19 vaccine (BNT162b2) in a cohort of chronic hemodialyzed patients.

Patients on hemodialysis (HD) have a high risk of death from COVID-19. We evaluated the humoral and cell-mediated immune response to BNT162b2 (Pfizer-BioNTech) vaccine in HD patients, comparing HD with Poly-methyl-methacrylate (PMMA) and HD with Polysulphone (PS). Samples were collected before vaccination (T0) and 14-days after the 2ndvaccine (T2) in a TG (TG, n = 16-Foggia) and in a VG (CG, n = 36-Novara). Anti-SARS-CoV-2-Ig were titrated in the cohort 2-weeks after the 2nddose of vaccine. In the Testing-Group, serum neutralizing antibodies (NAb) were assayed and PBMCs isolated from patients were thawed, counted and stimulated with SARS-CoV-2 IGRA stimulation tube set. All patients had a positive ab-response, except in a case. PMMA-patients had higher levels of anti-SARS-CoV-2 IgG (p = 0.031); VG data confirmed these findings (p < 0.05). NAb evaluation: PMMA patients passed the positive cut-off value, while in PS group only only 1/8 patient did not respond. PMMA patients showed higher percentages of anti-SARS-CoV-2 S1/RBD-Ig after a complete vaccine schedule (p = 0.028). Interferon-gamma release: PMMA patients showed significantly higher release of IFNγ (p = 0.014). The full vaccination course provided sufficient protection against SARS-CoV-2 across the entire cohort, regardless of dialyzer type. After vaccination, PMMA patients show a better immune response, both humoral and cellular, at the end of the vaccination course than PS patients.

Sequential administration of anti-complement component C5 eculizumab and type-2 anti-CD20 obinutuzumab for the treatment of early antibody-mediated rejection after kidney transplantation: A proof of concept.

Kidney transplant (KT) candidates with donor-specific antibodies (DSA) exhibit exceedingly high antibody-mediated rejection (ABMR) and allograft loss rates. Currently, treatment of ABMR remains an unmet clinical need. We report the use of the anti-C5 eculizumab and the type-2 anti-CD20 obinutuzumab in two patients with early ABMR. Eculizumab (900 mg IV) led to complete inhibition of the terminal complement cascade (unremarkable AP50 and CH50 activity) and prompt stoppage of complement-dependent antibody-mediated allograft injury (clearance of intra-graft C4d and C5b-9 deposition). Despite complement inhibition, obinutuzumab (1000 mg IV) determined full and long-lasting peripheral B-cell depletion, with significant reduction in all DSA. Graft function improved, remaining stable up to three years of follow-up. No signs of active ABMR and rebound DSA were detected. Obinutuzumab B-cell depletion and inhibition of DSA production were not affected by complement blockage. Further studies are needed to confirm the potential benefit of obinutuzumab in association with complement inhibitors.

Are Kidneys Affected by SARS-CoV-2 Infection? An Updated Review on COVID-19-Associated AKI.

BACKGROUND: Human kidneys are an important target of SARS-CoV-2 infection, and many renal abnormalities have been found in patients with SARS-CoV-2 infection, including proteinuria, hematuria, and acute kidney injury. Acute kidney injury is now considered a common complication of COVID-19, and the epidemiology of AKI in SARS-CoV-2-infected patients continues to be controversial. AIM AND METHODS: We have carried out a narrative review to evaluate the frequency and risk factors for AKI among patients hospitalized due to COVID-19, and the latest surveys on this topic have been included. The mechanisms by which AKI occurs in COVID-19 patients have also been reviewed. RESULTS: Multiple risk factors for the development of AKI in patients with SARS-CoV-2 infection have been identified; these have been classified in various groups (management and background factors, among others). SARS-CoV-2 targets the kidneys by indirect activity, but SARS-CoV-2 infects tubular epithelial cells and podocytes. We retrieved 24 reports (n = 502,593 unique patients with SARS-CoV-2 infection) and found an incidence of AKI of 31.8% (range, 0.5% to 56.9%). Only a minority (n = 2) of studies had a prospective design. We found that the AKI risk was greater in SARS-CoV-2 patients who underwent in-hospital deaths vs. those who survived; the summary estimate of the unadjusted RR of AKI was 2.63 (95% CI, 2.37; 2.93) (random-effects model). A stratified analysis showed that the incidence of AKI was greater in those reports where the frequency of COVID-19-positive patients having comorbidities (diabetes mellitus, arterial hypertension, and advanced age) was high. The unadjusted relative risk (aRR) of AKI was greater in SARS-CoV-2 patients who underwent ICU admission vs. those who did not; the pooled estimate of AKI risk was 2.64 (95% CI, 1.96; 3.56) according to the random-effects model. CONCLUSIONS: AKI is a common complication of hospitalized SARS-CoV-2-infected patients, and some comorbidities are important risk factors for it. The direct activity of the virus on the kidneys has been mentioned in the pathogenesis of AKI in SARS-CoV-2 patients. Further studies are ongoing in order to identify the mechanisms underlying the kidney injury in this population. The role of AKI on survival in SARS-CoV-2-infected patients is another area of active investigation.

Tunnel ultrasound can guide the use of peritoneal dialysis catheter exit site relocation by external splicing and cuff removal in refractory tunnel infection.

BACKGROUND: Peritoneal dialysis (PD) catheter related infections continue to be a major cause of morbidity and transfer to hemodialysis (HD) in PD patients. The treatment of tunnel infection (TI) could be challenging, especially when the infection involves the superficial cuff requiring the removal of the catheter. To spare the patient the loss of the catheter and the transfer to HD, several mini-invasive surgical techniques have been proposed as rescue therapy. Furthermore, nowadays, the rapid growth of digital technology has enormously increased the diagnostic sensibility of the echo signal allowing to accurately defines the extent of the infectious process along the PD catheter tunnel. METHODS: Between 1st January 2020 and 31st December 2021 seven patients who underwent exit-site relocation by external splicing and cuff removal at our institution due to refractory TI were included in the study. All patients were followed until 12 months after the procedure. As soon as TI was defined refractory to the medical therapy, an ultrasonographic examination of the catheter tunnel was performed to define the extent of the infectious episode. RESULTS: Among the 7 infectious episodes, 4 were caused by P. aeruginosa, and 3 by S. aureus. Around the superficial cuff the hypo/anechoic collections detected by ultrasounds showed a mean diameter of 3.05 ± 0.79 mm. The exit-site relocation by external splicing and cuff removal was successful in all cases (7/7, 100%). CONCLUSIONS: In our experience the use of exit site relocation by external splicing and cuff removal as rescue therapy for TI with positive ultrasounds for TI limited to superficial cuff involvement and without secondary peritonitis, yielded to promising results with a success rate of 100%. This preliminary experience underlines the paramount usefulness of tunnel echography in accurately defining the extent of TI and, consequently, guiding the choice of the therapeutical approach in refractory TI.

Corrigendum: Impact of hyperparathyroidism and its different subtypes on long term graft outcome: a single Transplant Center cohort study.

[This corrects the article DOI: 10.3389/fmed.2023.1221086.].

What Is Hidden in Patients with Unknown Nephropathy? Genetic Screening Could Be the Missing Link in Kidney Transplantation Diagnosis and Management.

Between 15-20% of patients with end stage renal disease (ESRD) do not know the cause of the primary kidney disease and can develop complications after kidney transplantation. We performed a genetic screening in 300 patients with kidney transplantation, or undiagnosed primary renal disease, in order to identify the primary disease cause and discriminate between overlapping phenotypes. We used a custom-made panel for next-generation sequencing (Agilent technology, Santa Clara, CA, USA), including genes associated with Fabry disease, podocytopaties, complement-mediated nephropathies and Alport syndrome-related diseases. We detected candidate diagnostic variants in genes associated with nephrotic syndrome and Focal Segmental Glomerulosclerosis (FSGS) in 29 out of 300 patients, solving about 10% of the probands. We also identified the same genetic cause of the disease (PAX2: c.1266dupC) in three family members with different clinical diagnoses. Interestingly we also found one female patient carrying a novel missense variant, c.1259C>A (p.Thr420Lys), in the GLA gene not previously associated with Fabry disease, which is in silico defined as a likely pathogenic and destabilizing, and associated with a mild alteration in GLA enzymatic activity. The identification of the specific genetic background may provide an opportunity to evaluate the risk of recurrence of the primary disease, especially among patient candidates living with a donor kidney transplant.

Outcome of atypical hemolytic uremic syndrome: role of triggers and complement abnormalities in the response to C5 inhibition.

BACKGROUND: Atypical-hemolytic uremic syndrome (aHUS) is a rare thrombotic microangiopathy often due to uncontrolled complement activation, characterized by high risk of end-stage kidney disease (ESKD). Eculizumab has improved the outcome, however, its efficacy varies among patients and its discontinuation is debated. METHODS: To identify characteristics associated with treatment response, we analyzed 244 aHUS patients referred to our center. Patients were classified according to the presence/absence of complement abnormalities and/or triggers at onset in 4 categories: (1) primary (complement abnormality without trigger), (2) secondary (trigger without complement abnormality), (3) combined (trigger and complement abnormality), (4) idiopathic (no trigger, no complement abnormality). Response to treatment was evaluated by comparing the response to eculizumab with that of conventional therapy. Short- and long-term outcomes were evaluated with the relapse rate after discontinuation of C5-inhibition. RESULTS: Patients had a better outcome with eculizumab compared to conventional treatment, with a response rate of 81.9% vs 56.9%, p < 0.001 and a long-term cumulative incidence of ESKD of 5.8% vs 22.5% (hazard ratio 0.25, 95% confidence interval: 0.10-0.80). The excellent global response was driven by the primary and combined groups (89.8% vs 54.0% and 89.3% vs 54.2%, respectively). The relapse rate following discontinuation of the C5-inhibitor was as high as 66.7% in the primary group, 18.7% in the combined, and 0% in the secondary and idiopathic groups. CONCLUSIONS: Our data show a better outcome in aHUS patients treated with C5-inhibition, particularly in the primary and combined forms, which have a high risk of relapse after discontinuation that is not observed in the secondary and idiopathic forms.

Relationship between number of daily exchanges at CAPD start with clinical outcomes.

BACKGROUND: Peritoneal dialysis (PD) continues to be demanding for patients affected by kidney failure. In kidney failure patients with residual kidney function, the employment of incremental PD, a less onerous dialytic prescription, could translate into a decrease burden on both health systems and patients. METHODS: Between 1st January 2009 and 31st December 2021, 182 patients who started continuous ambulatory peritoneal dialysis (CAPD) at our institution were included in the study. The CAPD population was divided into three groups according to the initial number of daily CAPD exchanges prescribed: one or two (50 patients, CAPD-1/2 group), three (97 patients, CAPD-3 group) and four (35 patients, CAPD-4 group), respectively. RESULTS: Multivariate analysis showed a difference in term of peritonitis free survival in CAPD-1/2 in comparison to CAPD-3 (hazard ratio (HR): 2.20, p = 0.014) and CAPD-4 (HR: 2.98, p < 0.01). A tendency towards a lower hospitalisation rate (CAPD-3 and CAPD-4 vs. CAPD-1/2, p = 0.11 and 0.13, respectively) and decreased mortality (CAPD-3 and CAPD-4 vs. CAPD-1/2, p = 0.13 and 0.22, respectively) in patients who started PD with less than three daily exchanges was detected. No discrepancy of the difference of the mean values between baseline and 24 months residual kidney function was observed among the three groups (p = 0.33). CONCLUSIONS: One- or two-exchange CAPD start was associated with a lower risk of peritonitis in comparison to three- or four-exchange start. Furthermore, an initial PD prescription with less than three exchanges may be associated with an advantage in term of hospitalisation rate and patient survival.