Klotho as an Early Marker of Acute Kidney Injury Following Cardiac Surgery: A Systematic Review.

Acute kidney injury is a common complication following cardiac surgery (CSA-AKI). Serum creatinine levels require a minimum of 24-48 h to indicate renal injury. Nevertheless, early diagnosis remains critical for improving patient outcomes. A PRISMA-compliant systematic review of the PubMed and CENTRAL databases was performed to assess the role of Klotho as a predictive biomarker for CSA-AKI (end-of-search date: 17 February 2024). An evidence quality assessment of the four included studies was performed with the Newcastle-Ottawa scale. Among the 234 patients studied, 119 (50.8%) developed CSA-AKI postoperatively. Serum Klotho levels above 120 U/L immediately postoperatively correlated with an area under the curve (AUC) of 0.806 and 90% sensitivity. Additionally, a postoperative serum creatinine to Klotho ratio above 0.695 showed 94.7% sensitivity and 87.5% specificity, with an AUC of 92.4%, maintaining its prognostic validity for up to three days. Urinary Klotho immunoreactivity was better maintained in samples obtained via direct catheterization rather than indwelling catheter collection bags. Storage at -80 °C was necessary for delayed testing. Optimal timing for both serum and urine Klotho measurements was from the end of cardiopulmonary bypass to the time of the first ICU lab tests. In conclusion, Klotho could be a promising biomarker for the early diagnosis of CSA-AKI. Standardization of measurement protocols and larger studies are needed to validate these findings.

The Han:SPRD Rat: A Preclinical Model of Polycystic Kidney Disease.

Autosomal Dominant Polycystic Kidney Disease (ADPKD) stands as the most prevalent hereditary renal disorder in humans, ultimately culminating in end-stage kidney disease. Animal models carrying mutations associated with polycystic kidney disease have played an important role in the advancement of ADPKD research. The Han:SPRD rat model, carrying an R823W mutation in the Anks6 gene, is characterized by cyst formation and kidney enlargement. The mutated protein, named Samcystin, is localized in cilia of tubular epithelial cells and seems to be involved in cystogenesis. The homozygous Anks6 mutation leads to end-stage renal disease and death, making it a critical factor in kidney development and function. This review explores the utility of the Han:SPRD rat model, highlighting its phenotypic similarity to human ADPKD. Specifically, we discuss its role in preclinical trials and its importance for investigating the pathogenesis of the disease and developing new therapeutic approaches.

Assessment of Donor Derived Cell Free DNA (dd-cfDNA) at Surveillance and at Clinical Suspicion of Acute Rejection in Renal Transplantation.

In our prospective, unicenter cohort study, we collected blood samples from 30 newly kidney transplanted patients, at month 1, 2, 3, and 5 for dd-cfDNA analysis, along with creatinine/eGFR and DSA monitoring, and from 32 patients who underwent an indication biopsy and whose dd-cfDNA levels were measured at the time of biopsy and 1 month afterwards. Fourteen of 32 (43.8%) patients in the biopsy group were diagnosed with TCMR and 5 of 32 (15.6%) with ABMR. Dd-cfDNA proved to be better than creatinine in diagnosing rejection from non-rejection in patients who were biopsied. When a dd-cfDNA threshold of 0.5% was chosen, sensitivity was 73.7% and specificity was 92.3% (AUC: 0.804, 0.646-0.961). In rejection patients, levels of dd-cfDNA prior to biopsy (0.94%, 0.3-2.0) decreased substantially after initiation of treatment with median returning to baseline already at 1 month (0.33%, 0.21-0.51, p = 0.0036). In the surveillance group, high levels of dd-cfDNA (>0.5%) from second month post-transplantation were correlated with non-increasing eGFR 1 year post-transplantation. The study used AlloSeq kit for kidney transplant surveillance for first time and confirmed dd-cfDNA's ability to detect rejection and monitor treatment, as well as to predict worse long-term outcomes regarding eGFR.

Multidisciplinary approach to lupus nephritis: Clinical pearls, pitfalls, and positioning of newly-approved agents.

Lupus nephritis (LN) is a major course of morbidity and mortality in patients with systemic lupus erythematosus (SLE), best managed by a multidisciplinary group. To this end, we gathered a group of rheumatologists, nephrologists and a nephropathologist to review current evidence regarding diagnosis and management of LN. In this consensus paper, we summarize the key points from this meeting and provide practice guidelines for the management of kidney involvement in SLE, in view of emerging new data concerning novel agents approved recently. Renal biopsy is indispensable for the management of LN. Yet, important pearls and pitfalls need to be considered regarding indications and interpretation, which are summarized in informative tables. In new-onset LN, experts agreed that, although belimumab may be added from disease onset, patients with moderate to severe proliferative nephritis (defined as: NIH activity index > 5 plus ≥ 1 of the following: (i) NIH chronicity index > 2, (ii) proteinuria > 3 g/24 h, and (iii) increase in serum creatinine > 20%) may be more likely to benefit the most. In all other patients who have already started standard-of-care treatment with either mycophenolate mofetil (MMF) or cyclophosphamide (CY), belimumab could be considered in cases with an inadequate clinical response by 3 months, or in cases that experience a nephritic flare following initial response, or have an inability to reduce the dose of glucocorticoids. In all circumstances, the drug should be given as add-on therapy, that is, in combination with a standard-of-care therapy (MMF or CY). Voclosporin could be considered for up to 3 years, in combination with MMF, in patients with heavy proteinuria (well above the nephrotic range), wherein a quick reduction of protein loss in urine is desirable to avoid the complications of the nephrotic syndrome, either as part of the initial regimen, or in cases of inadequate reduction of proteinuria with MMF. In view of the potential scarring effects, long-term administration beyond the first year requires further documentation.

A past medical history of autoimmune disease predicts a future with fewer relapses in patients with ANCA-associated vasculitis.

OBJECTIVES: To explore the frequency and impact of an autoimmune disease past-medical history (PMH) in the clinical picture and outcomes of patients with antineutrophil cytoplasmic autoantibodies (ANCA) associated vasculitis (AAV). METHODS: This was a retrospective study of patients with biopsy-proven AAV, >16 years old, with detailed information about their PMH. Outcomes of interest included remission, treatment resistance, relapse, end-stage kidney disease (ESKD), and death. RESULTS: 206 patients with biopsy-proven AAV and available information regarding their PMH were studied. 63(30.6%) of them had a history of autoimmune disease prior to AAV diagnosis. The mean age overall was 54.1 years. One hundred and five patients (51%) were positive for PR3-ANCA, 101 (49%) for MPO-ANCA. Granulomatosis with polyangiitis was diagnosed in 79 (38.3%), microscopic polyangiitis in 97 (47.1%) and renal-limited vasculitis in 30 (14.6%) individuals. Remission rate was similar among patients with and without a PMH of autoimmune disease. Time-to-event analysis indicated that the relapse-free survival was significantly longer in patients with PMH of autoimmune disease (148.2 vs. 61.9 months, p-value <0.001). After adjusting for covariates, autoimmune disease history was associated with significantly lower risk of relapse (HR: 0.33, 95% CI: 0.15-0.72), which remained significant in males, patients ≥60 years old and those with C/PR3-ANCA, kidney and lung involvement. CONCLUSIONS: Patients with a PMH of autoimmune disease, prior to AAV diagnosis, experienced significantly fewer relapses after achievement of remission, compared to patients without such a history, underlining the importance of individualisation of maintenance immunosuppressive therapy, given the different aetiopathogenetic settings the disease was developed.

Hypocomplementemia at Diagnosis of Pauci-immune Glomerulonephritis Is Associated With Advanced Histopathological Activity Index and High Probability of Treatment Resistance.

INTRODUCTION: Recent evidence suggests that complement activation is important in the pathogenesis of pauci-immune (PI) vasculitis. This is a retrospective investigation of the frequency of hypocomplementemia at pauci-immune glomerulonephritis (PIGN) diagnosis, in relation to vasculitic manifestations, renal histopathology, and treatment outcomes. METHODS: A total of 115 patients with biopsy-proven PIGN were categorized based on their serum complement C3 (sC3). Histopathology evaluation included activity and chronicity indexes. The primary outcome of interest was treatment resistance, defined as a progressive decline in kidney function, with persistently active urine sediment, leading to dialysis dependency or vasculitis-related death. RESULTS: In all, 20.9% of patients had low sC3 levels associated with more advanced renal impairment (P < 0.01), requiring acute dialysis (P < 0.01) more frequently compared to patients with normal sC3. Within 1 year, 85.7% of patients with normal sC3 responded to therapy, versus 58.3% of those with low sC3 (P = 0.001). The probability of treatment resistance was strongly associated with low sC3 (P = 0.004), high serum creatinine (P < 0.001), acute dialysis requirement (P < 0.001), and high histopathological score of chronicity (P < 0.01). Advanced histopathological activity was related to more intense interstitial leukocyte infiltration (P = 0.005) and higher likelihood of fibrinoid necrosis documentation in a vessel wall (P = 0.02). The probability of treatment resistance was higher in patients with low sC3 (odds ratio [OR] = 6.47, 95% confidence interval [CI] 1.47-28.35, P = 0.013), oliguria (OR = 29.57, 95% CI = 4.74-184, P < 0.0001), and high chronicity score (OR = 1.77, 95% CI = 1.23-2.54, P = 0.002). CONCLUSION: Low sC3 is emerging as an independent predictor of treatment resistance in patients with PIGN associated with higher index of histopathological activity at diagnosis compared to normal sC3.

A case report of hypocomplementemic urticarial vasculitis presenting with membranoproliferative glomerulonephritis.

BACKGROUND: Hypocomplementemic urticarial vasculitis syndrome is an infrequent condition characterized by ocular, renal, gastrointestinal and pulmonary involvement with low serum complement levels and autoantibodies. Renal manifestations vary from microscopic hematuria to nephrotic syndrome and acute kidney injury. Accordingly differing histologic patterns have been reported. CASE PRESENTATION: We present the case of a 65 years old woman with a history of chronic uveitis who presented with arthralgias, urticarial rush, nephrotic syndrome, glomerular hematuria and low serum complement. Kidney biopsy revealed an immune-complex membranoproliferative glomerulonephritis. The patient received induction therapy with steroids, cyclophosphamide and hydroxychloroquine followed by rapid clinical improvement and remission of proteinuria. Maintenance treatment consisted of rituximab pulses. CONCLUSIONS: The majority of hypocomplementemic urticarial vasculitis syndrome cases is idiopathic, although an association to drugs, infections or other autoimmune disorders has been recorded. Given the rarity and heterogeneity of the disease, no standard treatment is established.

B-cell oligoclonal expansions in renal tissue of patients with immune-mediated glomerular disease.

B-cell clonal expansion has been sporadically described in the blood and/or renal tissue of patients with glomerulonephritides, albeit with unclear pathogenetic role. Herein, using spectratyping analysis, we observed oligoclonal intrarenal B-cell populations in 59% of glomerulonephritis patients with podocyte injury (6/7 with focal segmental glomerulosclerosis, 1/3 minimal change disease, 1/3 idiopathic membranous nephropathy, 3/4 IgA nephropathy, 2/5 membranous lupus nephritis), 20% of glomerulonephritis patients without podocyte involvement (4/13 with mesangial or proliferative lupus nephritis, 0/3 idiopathic membranoproliferative glomerulonephritis, 0/4 pauci-immune vasculitis) and 17% of control patients with renal cancer. In multivariate analysis, oligoclonal B-cells were associated with podocyte injury and the grade of glomerulosclerosis (both p = .009). B-cell oligoclonal expansions were not found in the paired peripheral blood samples. We postulate that B-cell expansion in the kidney results from local stimuli, including antigens expressed on podocytes. Further studies to unravel the role of oligoclonal B-cells in (auto)immune-mediated kidney disease are warranted.

Efficacy and safety of new direct-acting antivirals in kidney transplant recipients with chronic hepatitis C: a single-center study.

BACKGROUND: The recent interferon-free direct-acting antiviral (DAA) regimens have very good safety and efficacy profiles and are highly recommended for kidney transplant (KT) recipients with chronic hepatitis C (CHC). METHODS: All KT recipients with CHC followed at our hospital and who received therapy with the current DAAs were included. At the baseline visit, demographic, clinical and laboratory variables before and after KT, as well as at the commencement of DAAs, at the end of antiviral therapy and the end of follow up, were recorded, including assessment of glomerular filtration rate (eGFR). The changes in eGFR (DGFR) between baseline and end of therapy (1st period), and between end of therapy and end of follow up (2nd period), were evaluated. RESULTS: Twelve KT recipients were retrospectively evaluated: 2 had received antiviral therapy in the past; 4 (33.3%) patients had genotype 1 and 3 (25%) genotype 4 CHC. The median stiffness was 11.9 kPa (range 5-16.8), while 5 patients, none with decompensated cirrhosis, had stiffness >12.5 kPa. Eight patients received a sofosbuvir-containing antiviral regimen (Group 1) and 4 patients received an antiviral regimen without sofosbuvir (Group 2). Eleven (91.7%) patients achieved a sustained virological response (SVR). One patient discontinued DAAs early after treatment and did not achieve SVR. Otherwise, DAAs were well tolerated and no rejection episode was recorded. The DGFRs in the 1st period and 2nd period did not differ significantly between Group 1 and Group 2 patients. CONCLUSION: In this real-world study of KT recipients with CHC, the high efficacy and clinically acceptable tolerability of DAAs were confirmed.

Coronary artery disease in renal transplant recipients: an angiographic study.

BACKGROUND: Cardiovascular disease is the leading cause of mortality in renal transplant recipients (RT). Coronary artery disease (CAD) in such patients is poorly studied. METHODS: During 2012-2017, 50 patients with a renal graft (functioning for a minimum of 6 months) were subjected to coronary angiography in our institution. They were matched (for age, gender, diabetes, and indication for angiography) with 50 patients with end-stage renal disease (ESRD) undergoing chronic dialysis and 50 patients with normal renal function who were subjected to coronary angiography during the same period. The extent and severity of CAD were assessed by using the SYNTAX score. RESULTS: RT had a significantly longer duration of ESRD than patients on dialysis (17.5±7.1 vs. 8.5±8.7 years, p<0.01). Mean SYNTAX score was 13.3±12.0 in RT, 20.6±17.5 in patients on dialysis, and 9.4±9.2 in control patients (p<0.01). At least one significantly calcified lesion was present in 75.7% of RT recipients, 92.1% of patients on dialysis, and 15.8% of control patients (p<0.01). Percutaneous coronary intervention (PCI) was successful in 93.8% of the attempted cases in RT, 75% of patients on chronic dialysis, and 100% of control patients (p=0.04). In the RT group, SYNTAX score significantly correlated with smoking (p=0.02) and the total vintage of ESRD (p=0.04). CONCLUSIONS: In this angiographic study, CAD was less severe in RT than in patients on long-term dialysis despite a longer duration of ESRD. Coronary artery calcification was highly prevalent after renal transplantation. PCI in RT had a high rate of angiographic success.

Pathogenesis and Management of Acute Kidney Injury in Patients with Nephrotic Syndrome Due to Primary Glomerulopathies.

Acute kidney injury in the context of nephrotic syndrome is a serious and alarming clinical problem. Largely, acute kidney injury is a relatively frequent complication among patients with comorbidities while it has been independently associated with an increased risk of adverse outcomes, including death and chronic kidney disease. Nephrotic syndrome, without hematuria or with minimal hematuria, includes a list of certain glomerulopathies; minimal change disease, focal segmental glomerulosclerosis and membranous nephropathy. In the light of primary nephrotic syndrome, pathophysiology of acute kidney injury is differentiated by the nature of the primary disease and the severity of the nephrotic state. This review aims to explore the clinical circumstances and pathogenetic mechanisms of acute kidney injury in patients with nephrotic syndrome due to primary glomerulopathies, focusing on newer perceptions regarding the pathogenesis and management of this complicated condition, for the prompt recognition and timely initiation of appropriate treatment in order to restore renal function to its baseline level. Prompt recognition of the precise cause of acute kidney injury is crucial for renal recovery. Clinical characteristics, laboratory and serological findings along with histopathological findings, if required, will reveal the implicated pathway leading to individualized approach and management.

Arterial Stiffness in Patients With Renal Transplantation; Associations With Co-morbid Conditions, Evolution, and Prognostic Importance for Cardiovascular and Renal Outcomes.

Patients with chronic kidney disease (CKD), particularly those with end-stage renal disease (ESRD), are at increased risk of cardiovascular events and mortality. The spectrum of arterial remodeling in CKD and ESRD includes atheromatosis of middle-sized conduit arteries and, most importantly, the process of arteriosclerosis, characterized by increased arterial stiffness of aorta and the large arteries. Longitudinal studies showed that arterial stiffness and abnormal wave reflections are independent cardiovascular risk factors in several populations, including patients with CKD and ESRD. Kidney transplantation is the treatment of choice for patients with ESRD, associated with improved survival and better quality of life in relation to hemodialysis or peritoneal dialysis. However, cardiovascular mortality in transplanted patients remains much higher than that in general population, a finding that is at least partly attributed to adverse lesions in the vascular tree of these patients, generated during the progression of CKD, which do not fully reverse after renal transplantation. This article attempts to provide an overview of the field of arterial stiffness in renal transplantation, discussing in detail available studies on the degree and the associations of arterial stiffness with other co-morbidities in renal transplant recipients, the prognostic significance of arterial stiffness for cardiovascular events, renal events and mortality in these individuals, as well as studies examining the changes in arterial stiffness following renal transplantation.

2019 update of the EULAR recommendations for the management of systemic lupus erythematosus.

Our objective was to update the EULAR recommendations for the management of systemic lupus erythematosus (SLE), based on emerging new evidence. We performed a systematic literature review (01/2007-12/2017), followed by modified Delphi method, to form questions, elicit expert opinions and reach consensus. Treatment in SLE aims at remission or low disease activity and prevention of flares. Hydroxychloroquine is recommended in all patients with lupus, at a dose not exceeding 5 mg/kg real body weight. During chronic maintenance treatment, glucocorticoids (GC) should be minimised to less than 7.5 mg/day (prednisone equivalent) and, when possible, withdrawn. Appropriate initiation of immunomodulatory agents (methotrexate, azathioprine, mycophenolate) can expedite the tapering/discontinuation of GC. In persistently active or flaring extrarenal disease, add-on belimumab should be considered; rituximab (RTX) may be considered in organ-threatening, refractory disease. Updated specific recommendations are also provided for cutaneous, neuropsychiatric, haematological and renal disease. Patients with SLE should be assessed for their antiphospholipid antibody status, infectious and cardiovascular diseases risk profile and preventative strategies be tailored accordingly. The updated recommendations provide physicians and patients with updated consensus guidance on the management of SLE, combining evidence-base and expert-opinion.

Impact of Primary Disease Nature in the Development of De Novo Donor-Specific Antibodies After Kidney Transplant and the Risk of Acute Rejection.

OBJECTIVES: In this study, we explored the effect of the primary disease nature on development of de novo donor-specific antibodies after kidney transplant. MATERIALS AND METHODS: We retrospectively studied kidney transplant recipients based on their primary disease. Patients were divided according to autoimmune and nonautoimmune diseases. The frequency of de novo donor-specific antibodies posttransplant and the incidence of acute rejection were estimated. De novo donor-specific antibodies were determined by the Luminex (LAB Screen products, One Lambda, Inc., Canoga Park, CA, USA) assay. RESULTS: Our study included 228 patients: 92 with autoimmune diseases and 136 with nonautoimmune diseases. Similar rates of de novo donor-specific antibodies (10.9% vs 11.8%; P = .835) were shown in the 2 groups over a mean (standard deviation) follow-up of 56.5 (27.8) months. In the nonautoimmune group, presence of de novo donor-specific antibodies was associated with higher rates of biopsy-proven acute rejection (37.5% vs 8.3%; odds ratio = 6.6; 95% confidence interval, 1.985-21.945; P = .002) versus that shown in patients of the same group without de novo donor-specific antibodies. In the autoimmune group, biopsy-proven acute rejection rates were similar between patients with and without de novo donor-specific antibodies. Mean fluorescence intensity titers of de novo donor-specific antibodies were significantly higher in patients with nonautoimmune primary disease (P = .003).Overall, graft loss was shown to be significantly higher in patients with autoimmune than in patients with nonautoimmune diseases (P < .001), although not different between patients with de novo donor-specific antibody formation (P = .677). CONCLUSIONS: No associations were shown between the frequency of de novo donor-specific antibody development after kidney transplant and the nature of the primary disease (autoimmune vs nonautoimmune). Detection of de novo donor-specific antibodies was associated with higher rates of biopsy-proven acute rejection among patients with nonautoimmune primary disease.

Celiac-like Enteropathy Associated With Mycophenolate Sodium in Renal Transplant Recipients.

BACKGROUND: Although colonic injury is a well-known complication of mycophenolic acid (MPA), the involvement of the upper gastrointestinal tract is less extensively documented. We present the occurrence of celiac-like duodenopathy manifested as a severe diarrhea syndrome in 2 renal transplant recipients on enteric-coated mycophenolate sodium. METHODS: The patients belong to a setting of 16 renal transplant recipients under MPA suffering from chronic diarrhea in the absence of MPA-related colitis. RESULTS: Both patients had a history of persistent diarrhea with significant weight loss. Colonic mucosa was unremarkable, whereas duodenal biopsies revealed celiac-like changes with increased epithelial cell apoptosis. Clinical symptoms completely resolved, and follow-up biopsies demonstrated normalization of histology after enteric-coated mycophenolate sodium withdrawal and switching to azathioprine. CONCLUSIONS: Celiac-like enteropathy seems to represent a rare side effect of MPA-associated immunosuppressive therapy and should be taken into account in the differential diagnosis of diarrhea in transplant recipients treated with MPA particularly in the absence of MPA-related colitis. As macroscopic lesions are usually missing, blind duodenal biopsies are necessary to establish the diagnosis.

Primary Hepatic Burkitt Lymphoma in a Kidney Transplant Recipient.

This is a case of a renal transplant recipient who developed a primary hepatic Burkitt lymphoma a few years after kidney transplantation. The past medical history of the patient was significant for anti-HCV positivity with liver histopathology showing minimal changes of grades 0 and 1, stage 0. She received a graft from a deceased donor, with rabbit antithymocyte globulin and methyl-prednisolone, as induction therapy, and was maintained on azathioprine, cyclosporine, and low dose methyl-prednisolone with normal renal function. Four years after KTx she presented with fatigue, hepatomegaly, and impaired liver function and the workup revealed multiple, variable-sized, low density nodules in the liver, due to diffuse monotonous infiltration of highly malignant non-Hodgkin lymphoma of B-cells, which turned out to be a Burkitt lymphoma. Bone marrow biopsy and spinal fluid exam were free of lymphoma cells. At time of lymphoma diagnosis she was shown to be positive for Epstein-Barr virus polymerase chain reaction. She received aggressive chemotherapy but died due to sepsis, as a result of toxicity of therapy.

IgA nephropathy in Greece: data from the registry of the Hellenic Society of Nephrology.

BACKGROUND: Natural history, predisposing factors to an unfavourable outcome and the effect of various therapeutic regimens were evaluated in a cohort of 457 patients with immunoglobulin A nephropathy (IgAN) and follow-up of at least 12 months. METHODS: Patients with normal renal function and proteinuria <1 g/24 h as well as those with serum creatinine (SCr) >2.5 mg/dL and/or severe glomerulosclerosis received no treatment. Patients with normal or impaired renal function and proteinuria >1 g/24 h for >6 months received daily oral prednisolone or a 3-day course of intravenous (IV) methylprednisolone followed by oral prednisolone per os every other day or a combination of prednisolone and azathioprine. The clinical outcome was estimated using the primary endpoints of end-stage renal disease and/or doubling of baseline SCr. RESULTS: The overall 10-year renal survival was 90.8%, while end-stage renal disease and doubling of baseline SCr developed in 9.2% and 14.7% of patients, respectively. Risk factors related to the primary endpoints were elevated baseline SCr, arterial hypertension, persistent proteinuria >0.5 g/24 h and severity of tubulointerstial fibrosis. There was no difference in the clinical outcome of patients treated by the two regimens of corticosteroids; nevertheless, remission of proteinuria was more frequent in patients who received IV methylprednisolone (P = 0.000). The combination of prednisolone with azathioprine was not superior to IV methylprednisolone followed by oral prednisolone. Side effects related to immunossuppressive drugs were observed in 12.8% of patients. CONCLUSION: The clinical outcome of patients with IgAN was related to the severity of clinical and histological involvement. The addition of azathioprine to a corticosteroid-based regimen for IgAN does not improve renal outcome.