Evaluating Single-Nucleotide Polymorphisms in Inflammasome Proteins and Serum Levels of IL-18 and IL-1ß in Kidney Interstitial Damage in Anti-Neutrophilic Cytoplasmic Antibody-Associated Vasculitis.

The inflammasome regulates the innate inflammatory response and is involved in autoimmune diseases. In this study, we explored the levels of IL-18 and IL-1ß in serum and urine and the influence of various single-nucleotide polymorphisms (SNPs) on kidney lesions at diagnosis in patients with ANCA-associated vasculitis (AAV) and their clinical outcomes. Ninety-two patients with renal AAV were recruited, and blood and urine were collected at diagnosis. Serum and urine cytokine levels were measured by ELISA. DNA was extracted and genotyped using TaqMan assays for SNPs in several inflammasome genes. Lower serum IL-18 (p = 0.049) and the IL-18 rs187238 G-carrier genotype (p = 0.042) were associated with severe fibrosis. The IL-18 rs1946518 TT genotype was associated with an increased risk of relapse (p = 0.05), whereas GG was related to better renal outcomes (p = 0.031). The rs187238 GG genotype was identified as a risk factor for mortality within the first year after AAV diagnosis, independent of the requirement for dialysis or lung involvement (p = 0.013). We suggest that decreased cytokine levels could be a surrogate marker of scarring and chronicity of the renal lesions, together with the rs187238 GG genotype. If our results are validated, the rs1946518 TT genotype predicts the risk of relapse and renal outcomes during follow-up.

Immune checkpoint inhibitors induce acute interstitial nephritis in mice with increased urinary MCP1 and PD-1 glomerular expression.

INTRODUCTION: Immune checkpoint inhibitors (ICIs) induce acute interstitial nephritis (AIN) in 2-5% of patients, with a clearly higher incidence when they are combined with platinum derivatives. Unfortunately, suitable disease models and non-invasive biomarkers are lacking. To fill this gap in our understanding, we investigated the renal effects of cisplatin and anti-PD-L1 antibodies in mice, assessing PD-1 renal expression and cytokine levels in mice with AIN, and then we compared these findings with those in AIN-diagnosed cancer patients. METHODS: Twenty C57BL6J mice received 200 µg of anti-PD-L1 antibody and 5 mg/kg cisplatin intraperitoneally and were compared with those receiving cisplatin (n = 6), anti-PD-L1 (n = 7), or saline (n = 6). After 7 days, the mice were euthanized. Serum and urinary concentrations of TNFα, CXCL10, IL-6, and MCP-1 were measured by Luminex. The kidney sections were stained to determine PD-1 tissue expression. Thirty-nine cancer patients with AKI were enrolled (AIN n = 33, acute tubular necrosis (ATN) n = 6), urine MCP-1 (uMCP-1) was measured, and kidney sections were stained to assess PD-1 expression. RESULTS: Cisplatin and anti PD-L1 treatment led to 40% AIN development (p = 0.03) in mice, accompanied by elevated serum creatinine and uMCP1. AIN-diagnosed cancer patients also had higher uMCP1 levels than ATN-diagnosed patients, confirming our previous findings. Mice with AIN exhibited interstitial PD-1 staining and stronger glomerular PD-1 expression, especially with combination treatment. Conversely, human AIN patients only showed interstitial PD-1 positivity. CONCLUSIONS: Only mice receiving cisplatin and anti-PDL1 concomitantly developed AIN, accompanied with a more severe kidney injury. AIN induced by this drug combination was linked to elevated uMCP1, consistently with human AIN, suggesting that uMCP1 can be potentially used as an AIN biomarker.

Combining neutrophil and macrophage biomarkers to detect active disease in ANCA vasculitis: a combinatory model of calprotectin and urine CD163.

Background: CD163 and calprotectin have been proposed as biomarkers of active renal vasculitis. This study aimed to determine whether the combination of serum/urine calprotectin (s/uCalprotectin) and urinary soluble CD163 (suCD163) increases their individual performance as activity biomarkers. Methods: We included 138 patients diagnosed with ANCA vasculitis (n = 52 diagnostic phase, n = 86 remission). The study population was divided into the inception (n = 101) and the validation cohorts (n = 37). We determined the s/uCalprotectin and suCD163 concentration using enzyme-linked immunoassay at the diagnostic or at the remission phase. Receiver operating characteristic (ROC) curves were conducted to assess the biomarkers' classificatory values. We elaborated a combinatorial biomarker model in the inception cohort. The ideal cutoffs were used in the validation cohort to confirm the model's accuracy in the distinction between active disease and remission. We added the classical ANCA vasculitis activity biomarkers to the model to increase the classificatory performance. Results: The concentrations of sCalprotectin and suCD163 were higher in the diagnostic compared with the remission phase (P = .013 and P < .0001). According to the ROC curves, sCalprotectin and suCD163 were accurate biomarkers to discern activity [area under the curve 0.73 (0.59-0.86), P = .015 and 0.88 (0.79-0.97), P < .0001]. The combinatory model with the best performance in terms of sensitivity, specificity and likelihood ratio included sCalprotectin, suCD163 and haematuria. Regarding the inception and the validation cohort, we obtained a sensitivity, specificity and likelihood ratio of 97%, 90% and 9.7, and 78%, 94% and 13, respectively. Conclusions: In patients with ANCA vasculitis, a predictive model combining sCalprotectin, suCD163 and haematuria could be useful in detecting active kidney disease.

Collapsing Glomerulonephritis in a Kidney Transplant Recipient after mRNA SARS-CoV-2 Vaccination.

With the vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), studies are describing cases of glomerulonephritis arising after vaccination. We present the first case of a kidney transplant patient who, after mRNA vaccination against SARS-CoV-2, developed nephrotic proteinuria and renal dysfunction, with a biopsy diagnostic of collapsing glomerulonephritis. No other triggers for this glomerulonephritis were identified. Antibodies against the spike protein were negative, but the patient developed a specific T-cell response. The close time between vaccination and the proteinuria suggests a possible determinant role of vaccination. We should be aware of nephropathies appearing after COVID-19 vaccination in kidney transplant recipients also.

Th1 Cytokines Signature in 2 Cases of IgA Nephropathy Flare after mRNA-Based SARS-CoV-2 Vaccine: Exploring the Pathophysiology.

mRNA-based vaccines have dramatically shifted the course of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. IgA nephropathy (IgAN) flare is the most reported renal adverse effect after the administration of these vaccines. Unraveling the mechanistic pathways leading to these flares is necessary to confirm a causal association. Herein, we report 2 cases of IgAN flare after SARS-CoV-2 vaccination in patients previously diagnosed with IgAN. We describe and compare the clinical and analytical features of the disease at the time of the diagnostic with the post-vaccine flare. In addition, we obtained serum and urine of these patients at the moment of the flare and determined the levels of IL-2, TNF-α, and IFNγ using a multiplex bead-based assay. As diseased controls, we included n = 13 patients diagnosed with IgAN who had available serum and urine samples at the moment of the diagnostic stored in our biobank. We also included 6 healthy controls. Compared to the first episode, postvaccination flares were more severe in terms of peak serum creatinine, albuminuria, and urinary erythrocyte count. The histological lesions found at the biopsy performed during the post-vaccine flare were similar to those found at the diagnostic. One of the patients who suffered a post-vaccine flare showed increased serum IL-2 and TNFα compared to the IgAN-diseased controls and the healthy controls. In conclusion, although several cases of post-vaccine IgAN flares have been reported, there are no mechanistic studies on the occurrence of these flares. We here suggest that hyperactivation of the Th1 pathway may be involved, but larger studies with more refined methods for numerical and functional Th1 lymphocytes evaluation are required.

The Role of Inflammasomes in Glomerulonephritis.

The inflammasome is an immune multiprotein complex that activates pro-caspase 1 in response to inflammation-inducing stimuli and it leads to IL-1ß and IL-18 proinflammatory cytokine production. NLRP1 and NLRP3 inflammasomes are the best characterized and they have been related to several autoimmune diseases. It is well known that the kidney expresses inflammasome genes, which can influence the development of some glomerulonephritis, such as lupus nephritis, ANCA glomerulonephritis, IgA nephropathy and anti-GBM nephropathy. Polymorphisms of these genes have also been described to play a role in autoimmune and kidney diseases. In this review, we describe the main characteristics, activation mechanisms, regulation and functions of the different inflammasomes. Moreover, we discuss the latest findings about the role of the inflammasome in several glomerulonephritis from three different points of view: in vitro, animal and human studies.

Predictors of outcome in a Spanish cohort of patients with Fabry disease on enzyme replacement therapy / Predictores de eventos clínicos en una cohorte de pacientes con enfermedad de Fabry en tratamiento sustitutivo enzimático

Fabry disease may be treated by enzyme replacement therapy (ERT), but the impact of chronic kidney disease (CKD) on the response to therapy remains unclear. The aim of the present study was to analyse the incidence and predictors of clinical events in patients on ERT. Study design: Multicentre retrospective observational analysis of patients diagnosed and treated with ERT for Fabry disease. The primary outcome was the first renal, neurological or cardiological events or death during a follow-up of 60 months (24–120). Results: In 69 patients (42 males, 27 females, mean age 44.6±13.7 years), at the end of follow-up, eGFR and the left ventricular septum thickness remained stable and the urinary albumin: creatinine ratio tended to decrease, but this decrease only approached significance in patients on agalsidase-beta (242–128mg/g (p=0.05). At the end of follow-up, 21 (30%) patients had suffered an incident clinical event: 6 renal, 2 neurological and 13 cardiological (including 3 deaths). Events were more frequent in patients with baseline eGFR≤60ml/min/1.73m2 (log Rank 12.423, p=0.001), and this remained significant even after excluding incident renal events (log Rank 4.086, p=0.043) and in males and in females. Lower baseline eGFR was associated with a 3- to 7-fold increase the risk of clinical events in different Cox models. Conclusions: GFR at the initiation of ERT is the main predictor of clinical events, both in males and in females, suggesting that start of ERT prior to the development of CKD is associated with better outcomes. (AU)

El objetivo de este estudio es realizar un mapa del tratamiento actual de la enfermedad de Fabry en España, analizando el efecto de diferentes factores en el desarrollo de eventos clínicos a largo plazo. Diseño del estudio: Análisis observacional retrospectivo multicéntrico. Criterios de inclusión: pacientes diagnosticados y tratados de enfermedad de Fabry. Se recogieron datos generales en relación con el diagnóstico, síntomas y tipo mutación, tipo de tratamiento recibido, evolución renal y cardiológica. Durante un tiempo de seguimiento de 60 meses (24-120), se recogió el primer evento clínico tras el inicio de tratamiento sustitutivo enzimático definido como mortalidad, evento renal, cardiológico o neurológico. Resultados: Se incluyeron 69 pacientes (42 H, 27 M) con una edad media de 44,6±13,7 años. A los cinco años de tratamiento, el FGe y la hipertrofia ventricular izquierda se mantuvieron estables, y la albuminuria tiende a disminuir, siendo este descenso más significativo en el grupo de pacientes tratados con beta-galactosidasa (de 242 a 128mg/g (p=0,05). Veintiún pacientes sufrieron un evento clínico (30%): seis renales, dos neurológicos y 13 cardiológicos (incluidas tres muertes). Los pacientes con ERC (FGe<60) antes del inicio de tratamiento tuvieron más eventos (log-rank 12.423, p=0,001), manteniéndose la predicción si excluíamos los eventos renales (log-rank 4.086 (p=0,043) en hombres y mujeres. La peor función renal al inicio del tratamiento aumentó entre tres y siete veces el riesgo de eventos clínicos en diferentes modelos de Cox ajustados. Conclusiones: La función renal al inicio de tratamiento sustitutivo enzimático es la principal predictora de desarrollo de eventos clínicos a largo plazo, tanto en hombres como mujeres. El inicio de tratamiento sustitutivo enzimático precoz antes del desarrollo de ERC mejoraría el pronóstico. (AU)

Urinary Cytokines Reflect Renal Inflammation in Acute Tubulointerstitial Nephritis: A Multiplex Bead-Based Assay Assessment.

BACKGROUND: Acute tubulointerstitial nephritis (ATIN) diagnosis lays on histological assessment through a kidney biopsy, given the absence of accurate non-invasive biomarkers. The aim of this study was to evaluate the accuracy of different urinary inflammation-related cytokines for the diagnostic of ATIN and its distinction from acute tubular necrosis (ATN). METHODS: We included 33 patients (ATIN (n = 21), ATN (n = 12)), and 6 healthy controls (HC). We determined the urinary levels of 10 inflammation-related cytokines using a multiplex bead-based Luminex assay at the time of biopsy and after therapy, and registered main clinical, analytical and histological data. RESULTS: At the time of biopsy, urinary levels of I-TAC/CXCL11, CXCL10, IL-6, TNFα and MCP-1 were significantly higher in ATIN compared to HC. A positive correlation between the extent of the tubulointerstitial cellular infiltrates in kidney biopsies and the urinary concentration of I-TAC/CXCL11, MIG/CXCL9, CXCL10, IL17, IFNα, MCP1 and EGF was observed. Notably, I-TAC/CXCL11, IL-6 and MCP-1 were significantly higher in ATIN than in ATN, with I-TAC/CXCL11 as the best discriminative classifier AUC (0.77, 95% CI 0.57-0.95, p = 0.02). A combinatory model of these three urinary cytokines increased the accuracy in the distinction of ATIN/ATN compared to the individual biomarkers. The best model resulted when combining the three cytokines with blood eosinophil and urinary leukocyte counts (LR = 9.76). Follow-up samples from 11ATIN patients showed a significant decrease in I-TAC/CXCL11, MIG/CXCL9 and CXCL10 levels. CONCLUSIONS: Urinary I-TAC/CXCL11, CXCL10, IL6 and MCP-1 levels accurately distinguish patients developing ATIN from ATN and healthy individuals and may serve as novel non-invasive biomarkers in this disease.

Predictors of outcome in a Spanish cohort of patients with Fabry disease on enzyme replacement therapy.

Fabry disease may be treated by enzyme replacement therapy (ERT), but the impact of chronic kidney disease (CKD) on the response to therapy remains unclear. The aim of the present study was to analyse the incidence and predictors of clinical events in patients on ERT. STUDY DESIGN: Multicentre retrospective observational analysis of patients diagnosed and treated with ERT for Fabry disease. The primary outcome was the first renal, neurological or cardiological events or death during a follow-up of 60 months (24-120). RESULTS: In 69 patients (42 males, 27 females, mean age 44.6±13.7 years), at the end of follow-up, eGFR and the left ventricular septum thickness remained stable and the urinary albumin: creatinine ratio tended to decrease, but this decrease only approached significance in patients on agalsidase-beta (242-128mg/g (p=0.05). At the end of follow-up, 21 (30%) patients had suffered an incident clinical event: 6 renal, 2 neurological and 13 cardiological (including 3 deaths). Events were more frequent in patients with baseline eGFR≤60ml/min/1.73m2 (log Rank 12.423, p=0.001), and this remained significant even after excluding incident renal events (log Rank 4.086, p=0.043) and in males and in females. Lower baseline eGFR was associated with a 3- to 7-fold increase the risk of clinical events in different Cox models. CONCLUSIONS: GFR at the initiation of ERT is the main predictor of clinical events, both in males and in females, suggesting that start of ERT prior to the development of CKD is associated with better outcomes.

Predictors of outcome in a Spanish cohort of patients with Fabry disease on enzyme replacement therapy.

Fabry disease may be treated by enzyme replacement therapy (ERT), but the impact of chronic kidney disease (CKD) on the response to therapy remains unclear. The aim of the present study was to analyse the incidence and predictors of clinical events in patients on ERT. STUDY DESIGN: Multicentre retrospective observational analysis of patients diagnosed and treated with ERT for Fabry disease. The primary outcome was the first renal, neurological or cardiological events or death during a follow-up of 60 months (24-120). RESULTS: In 69 patients (42 males, 27 females, mean age 44.6±13.7 years), at the end of follow-up, eGFR and the left ventricular septum thickness remained stable and the urinary albumin: creatinine ratio tended to decrease, but this decrease only approached significance in patients on agalsidase-beta (242-128mg/g (p=0.05). At the end of follow-up, 21 (30%) patients had suffered an incident clinical event: 6 renal, 2 neurological and 13 cardiological (including 3 deaths). Events were more frequent in patients with baseline eGFR≤60ml/min/1.73m2 (log Rank 12.423, p=0.001), and this remained significant even after excluding incident renal events (log Rank 4.086, p=0.043) and in males and in females. Lower baseline eGFR was associated with a 3- to 7-fold increase the risk of clinical events in different Cox models. CONCLUSIONS: GFR at the initiation of ERT is the main predictor of clinical events, both in males and in females, suggesting that start of ERT prior to the development of CKD is associated with better outcomes.