Transjugular Renal Biopsy Bleeding Risk and Diagnostic Yield: A Systematic Review

Investigating the impact of inflammatory response-related genes on renal fibrosis diagnosis: a machine learning-based study with experimental validation

Renal fibrosis plays a crucial role in the progression of renal diseases, yet the lack of effective diagnostic markers poses challenges in scientific and clinical practices. In this study, we employed machine learning techniques to identify potential biomarkers for renal fibrosis. Utilizing two datasets from the GEO database, we applied LASSO, SVM-RFE and RF algorithms to screen for differentially expressed genes related to inflammatory responses between the renal fibrosis group and the control group. As a result, we identified four genes (CCL5, IFITM1, RIPK2, and TNFAIP6) as promising diagnostic indicators for renal fibrosis. These genes were further validated through in vivo experiments and immunohistochemistry, demonstrating their utility as reliable markers for assessing renal fibrosis. Additionally, we conducted a comprehensive analysis to explore the relationship between these candidate biomarkers, immunity, and drug sensitivity. Integrating these findings, we developed a nomogram with a high discriminative ability, achieving a concordance index of 0.933, enabling the prediction of disease risk in patients with renal fibrosis. Overall, our study presents a predictive model for renal fibrosis and highlights the significance of four potential biomarkers, facilitating clinical diagnosis and personalized treatment. This finding presents valuable insights for advancing precision medicine approaches in the management of renal fibrosis.Communicated by Ramaswamy H. Sarma.

Renal Biopsy for Diagnosis in Kidney Disease: Indication, Technique, and Safety

Renal biopsies are the gold standard for diagnosis, staging, and prognosis of underlying parenchymal kidney disease. This article provides an overview of the current indications and highlights ways to reduce bleeding complications in order to achieve optimal diagnostic yield with minimal risk to the patient. Novel indications have emerged from the increasing use of new molecularly targeted oncologic therapies in recent years, which often induce immune-mediated renal disease. On the other hand, the detection of specific antibodies against target antigens on podocytes in the sera of patients with new-onset nephrotic syndrome has now relativized the indication for biopsy in membranous nephropathy. The use of semi-automatic spring-loaded biopsy devices and real-time ultrasound considerably declined the complication rate and is the current standard. Percutaneous renal biopsies are overall a safe procedure if contraindications are considered. A coagulation disorder needs to be excluded beforehand, and an elevated blood pressure must be reduced to the normotensive range with medications. A laparoscopic approach or a radiology interventional procedure through the internal jugular vein may be considered for obtaining a kidney tissue sample if there is an urgent indication and a bleeding tendency cannot be adequately corrected. Major bleeding after a percutaneous renal biopsy can usually be managed with selective arterial embolization of the injured renal vessel. The use of a 16-gauge needle is the most reasonable compromise between diagnostic benefit and risk of complication. In the routine diagnostic, the biopsy specimen is examined with light microscopy, immunohistochemistry, and electron microscopy. Combination with modern molecular pathology techniques will contribute to more precise insights into the development and progression of kidney disease, which will likely refine future treatments in nephrology.

Revealing Potential Diagnostic Gene Biomarkers Associated with Immune Infiltration in Patients with Renal Fibrosis Based on Machine Learning Analysis

Chronic kidney disease is characterized by the development of renal fibrosis. The basic mechanisms of renal fibrosis have not yet been fully investigated despite significant progress in understanding the etiology of the disease. In this work, the researchers sought to identify potential diagnostic indicators for renal fibrosis. From the GEO database, we were able to acquire two gene expression profiles with publically available data (GSE22459 and GSE76882, respectively) from human renal fibrosis and control samples. 215 renal fibrosis specimens and 124 normal specimens were examined for differentially expressed genes (DEGs). The SVM-RFE and LASSO regression models were used to discover potential markers. CIBERSORT was applied to estimate the combined cohorts' immune cell fraction compositional trends in renal fibrosis. RT-PCR was used to examine the expression of ISG20 in renal fibrosis and healthy samples. In vitro experiments were applied to examine the function of ISG20 knockdown on the progression of renal fibrosis. In this study, we identified 24 DEGs. The result of LASSO and SVM-RFE identified nine critical genes. ROC assays confirmed the diagnostic value of the above nine genes for renal fibrosis. Immune cell infiltration analysis revealed that ISG20 and SERPINA3 were both found to be correlated with T cell follicular helper, neutrophils, T cell CD4 memory activated, eosinophils, T cell CD8, dendritic cell activated, B cell memory, monocytes, macrophage M2, plasma cells, T cell CD4 naïve, mast cell resting, B cell naïve, T cell regulatory, and NK cell activated. Finally, we observed that the expression of ISG20 and SERPINA3 was distinctly increased in renal fibrosis samples compared with normal samples. ISG20 siRNA significantly suppressed the progression of renal fibrosis in vitro. Overall, this study identified nine diagnostic biomarkers for renal fibrosis. ISG20 may be a novel therapeutic target of renal fibrosis.

Safety of Obtaining an Extra Biobank Kidney Biopsy Core

Background and objectives: Kidney biopsy (KB) is the “gold standard” for the diagnosis of nephropathies and it is a diagnostic tool that presents a low rate of complications. Nowadays, biobank collections of renal tissue of patients with proven renal pathology are essential for research in nephrology. To provide enough tissue for the biobank collection, it is usually needed to obtain an extra kidney core at the time of kidney biopsy. The objective of our study is to evaluate the complications after KB and to analyze whether obtaining an extra core increases the risk of complications. Material and methods: Prospective observational study of KBs performed at Vall d’Hebron Hospital between 2019 and 2020. All patients who accepted to participate to our research biobank of native kidney biopsies were included to the study. Clinical and laboratory data were reviewed and we studied risk factors associated with complications. Results: A total of 221 patients were included, mean age 56.6 (±16.8) years, 130 (58.8%) were men, creatinine was 2.24 (±1.94) mg/dL, proteinuria 1.56 (0.506–3.590) g/24 h, hemoglobin 12.03 (±2.3) g/dL, INR 0.99 (±0.1), and prothrombin time (PT) 11.86 (±1.2) s. A total of 38 patients (17.2%) presented complications associated with the procedure: 13.1% were minor complications, 11.3% (n = 25) required blood transfusion, 1.4% (n = 3) had severe hematomas, 2.3% (n = 5) required embolization, and 0.5% (n = 1) presented arterio-venous fistula. An increased risk for complication was independently associated with obtaining a single kidney core (vs. 2 and 3 cores) (p = 0.021). Conclusions: KB is an invasive and safe procedure with a low percentage of complications. Obtaining an extra kidney core for research does not increase the risk of complications during the intervention, which remains low in concordance with previously published reports.

Complications after native kidney biopsy: definitive data

PURPOSE OF REVIEW

To assess the risk of complications associated with native kidney biopsies. This review will highlight recent advances on the risk factors for major bleeding and risk management in patients with native kidney biopsy.

RECENT FINDINGS

Recent studies provided new important data regarding the individualization of the risk of bleeding after kidney biopsy. A new bleeding risk score was proposed as a risk stratification tool, useful for shared decision making and procedure choice.

SUMMARY

The risk of complications is low (<1%) in most patients but varies widely. Risk factors include Charlson index, frailty index, female gender, dyslipidemia, anemia, thrombocytopenia, cancer, abnormal kidney function, glomerular disease, autoimmune disease, vasculitis, hematologic disease, and thrombotic microangiopathy. A new bleeding score can help physicians and patients to assess the risk of bleeding enabling informed consent, and decide to perform it or not, and to prefer transjugular vs percutaneous route.

Major Bleeding of Transjugular Native Kidney Biopsies. A French Nationwide Cohort Study

Introduction

The risk of bleeding associated with transjugular kidney biopsies is unclear, and which patients are the best candidates for this route is unknown.

Methods

This was a retrospective cohort study comparing proportion of bleeding associated with transjugular versus percutaneous native kidney biopsies in all patients in France in the 2010–2019 period. Major bleeding at day 8 (i.e., blood transfusions, hemorrhage/hematoma, angiographic intervention, nephrectomy) and risk of death at day 30 were assessed, and we used a bleeding risk score initially developed for the percutaneous route.

Results

Our analysis included 60,331 patients (transjugular route: 5305; percutaneous route: 55,026 patients). The observed proportion of major bleeding varied widely (transjugular vs. percutaneous): 0.4% versus 0.5% for the lowest risk scores (0–4) to 19.1% versus 30.8% for the highest risk scores (≥35). Transjugular was more frequently used than percutaneous route (39% vs. 24%) when the risk score was ≥20 (15,133/60,331; 25% of all patients). Transjugular was associated with a lower risk of major bleeding than percutaneous route in multivariate analyses (odds ratio [OR]: 0.88 [0.78–0.99]), especially for scores ≥20 (OR: 0.83 [0.72–0.96], (i.e., 25% of patients). Major bleeding was associated with an increased risk of death both for transjugular (OR: 1.77 [1.00–3.14]) and percutaneous (OR: 1.80 [1.43–2.28]) routes.

Conclusions

The transjugular route is independently associated with a lower risk of bleeding than the percutaneous route, especially in high-risk patients identified by a preprocedure risk score ≥20 (i.e., 25% of patients). Major bleeding is associated with an increased risk of death for both routes.