Bleeding complications of native kidney biopsy: a systematic review and meta-analysis

Arterial Stiffness is an Independent Risk Factor for Anemia After Percutaneous Native Kidney Biopsy

BACKGROUND/AIMS

Bleeding is the most common complication after renal biopsy. Although numerous predictors of bleeding have been reported, it remains unclear whether arterial stiffness affects bleeding complications.

METHOD

We performed an observational study of the renal biopsies performed in our division over an approximately 6-year period (May 2010 to May 2016). The clinical and laboratory factors were analyzed to reveal the risk factors associated with bleeding, with a focus on anemia (defined as a ≥10% decrease in hemoglobin [Hb] after biopsy). The brachial-ankle pulse wave velocity (baPWV) was measured to evaluate arterial stiffness.

RESULTS

This study included 462 patients (male, n=244; female, n=218). Anemia (defined above) was observed in 54 patients (11.7%). The risk of anemia was higher in women, older patients, and patients with lower serum albumin, lower eGFR and lower diastolic blood pressure after biopsy. We then performed a further analysis of 187 patients whose baPWV data were available. Multivariate analysis revealed that a higher baPWV was an independent risk factor for anemia. ROC analysis for predicting anemia found that a baPWV value of 1839 cm/s had the best performance (AUC 0.689).

CONCLUSION

An increased baPWV may be a more valuable predictor of bleeding than any of the other reported risk factors.

Innovative Perspective: Gadolinium-Free Magnetic Resonance Imaging in Long-Term Follow-Up after Kidney Transplantation

Since the mid-1980s magnetic resonance imaging (MRI) has been investigated as a non- or minimally invasive tool to probe kidney allograft function. Despite this long-standing interest, MRI still plays a subordinate role in daily practice of transplantation nephrology. With the introduction of new functional MRI techniques, administration of exogenous gadolinium-based contrast agents has often become unnecessary and true non-invasive assessment of allograft function has become possible. This raises the question why application of MRI in the follow-up of kidney transplantation remains restricted, despite promising results. Current literature on kidney allograft MRI is mainly focused on assessment of (sub) acute kidney injury after transplantation. The aim of this review is to survey whether MRI can provide valuable diagnostic information beyond 1 year after kidney transplantation from a mechanistic point of view. The driving force behind chronic allograft nephropathy is believed to be chronic hypoxia. Based on this, techniques that visualize kidney perfusion and oxygenation, scarring, and parenchymal inflammation deserve special interest. We propose that functional MRI mechanistically provides tools for diagnostic work-up in long-term follow-up of kidney allografts.

Peri-procedural use of anticoagulants in radiology: an evidence-based review

Peri-procedural anticoagulant management hinges on the balance of hemorrhagic and thrombotic complications. The radiologist is tasked with accurately assessing the hemorrhagic risk for patients undergoing procedures, taking into account procedural bleeding rates, underlying coagulopathy based on lab tests, and use of anticoagulants. The purpose of this article is to provide a contemporary review of commonly used anticoagulants and, incorporating published evidence, review their management related to image-guided procedures.

Chronic Kidney Disease

The definition and classification of chronic kidney disease (CKD) have evolved over time, but current international guidelines define this condition as decreased kidney function shown by glomerular filtration rate (GFR) of less than 60 mL/min per 1·73 m², or markers of kidney damage, or both, of at least 3 months duration, regardless of the underlying cause. Diabetes and hypertension are the main causes of CKD in all high-income and middle-income countries, and also in many low-income countries. Incidence, prevalence, and progression of CKD also vary within countries by ethnicity and social determinants of health, possibly through epigenetic influence. Many people are asymptomatic or have non-specific symptoms such as lethargy, itch, or loss of appetite. Diagnosis is commonly made after chance findings from screening tests (urinary dipstick or blood tests), or when symptoms become severe. The best available indicator of overall kidney function is GFR, which is measured either via exogenous markers (eg, DTPA, iohexol), or estimated using equations. Presence of proteinuria is associated with increased risk of progression of CKD and death. Kidney biopsy samples can show definitive evidence of CKD, through common changes such as glomerular sclerosis, tubular atrophy, and interstitial fibrosis. Complications include anaemia due to reduced production of erythropoietin by the kidney; reduced red blood cell survival and iron deficiency; and mineral bone disease caused by disturbed vitamin D, calcium, and phosphate metabolism. People with CKD are five to ten times more likely to die prematurely than they are to progress to end stage kidney disease. This increased risk of death rises exponentially as kidney function worsens and is largely attributable to death from cardiovascular disease, although cancer incidence and mortality are also increased. Health-related quality of life is substantially lower for people with CKD than for the general population, and falls as GFR declines. Interventions targeting specific symptoms, or aimed at supporting educational or lifestyle considerations, make a positive difference to people living with CKD. Inequity in access to services for this disease disproportionally affects disadvantaged populations, and health service provision to incentivise early intervention over provision of care only for advanced CKD is still evolving in many countries.

Risk factors for bleeding complications after nephrologist-performed native renal biopsy

Background

Bleeding is a recognized complication of native percutaneous renal biopsy. This study aimed to describe the incidence of major bleeding after biopsy in a single centre over a 15-year period and examine factors associated with major bleeding.

Methods

We identified consecutive adult patients undergoing ultrasound-guided native renal biopsy in the Glasgow Renal and Transplant Unit from 2000 to 2014. From the electronic patient record, we collected data pertaining to biopsy indication, pre- and post-biopsy laboratory measurements, prescribed medication and diagnosis. Aspirin was routinely continued. We defined major bleeding post-biopsy as the need for blood transfusion, surgical or radiological intervention or death. Binary logistic regression analysis was used to assess factors associated with increased risk of major bleeding.

Results

There were 2563 patients who underwent native renal biopsy (1499 elective, 1064 emergency). The average age of patients was 57 (SD 17) years and 57.4% were male. Overall, the rate of major bleeding was 2.2%. In all, 46 patients required transfusion (1.8%), 9 patients underwent embolization (0.4%), no patient required nephrectomy and 1 patient died as a result of a significant late retroperitoneal bleed. Major bleeding was more common in those undergoing emergency compared with elective renal biopsy (3.4 versus 1.1%; P < 0.001). Aspirin was being taken at the time of biopsy in 327 of 1509 patients, with no significant increase in the risk of major bleeding (P = 0.93). Body mass index (BMI) data were available for 546 patients, with no increased risk of major bleeding in 207 patients classified as obese (BMI >30).

Conclusions

The risk of major bleeding following native renal biopsy in the modern era is low. Complications are more common when biopsy is conducted as an emergency, which has implications for obtaining informed consent. Our data support the strategy of not stopping aspirin before renal biopsy.

Interstitial nephritis associated with ulcerative colitis in monozygotic twins

Although renal impairment is a rare complication of ulcerative colitis (UC), interstitial nephritis can occur as an idiosyncratic reaction to 5-aminosalicylate (5-ASA) treatment for UC. Monozygotic twins developed UC at ages 49 and 51, and they were separately treated at different medical institutes. They did not know that they had the same disease and were treated with the same drug (5-ASA). During the course of 5-ASA treatment, renal impairment diagnosed as interstitial nephritis occurred in both. Granulocyte/monocyte adsorption was initiated, UC remission was achieved and renal function deterioration subsided in both. Drug or treatment responses may be concordant in monozygotic twins with UC. Careful review is important before treatment to avoid serious adverse events.

Comparative differential proteomic analysis of minimal change disease and focal segmental glomerulosclerosis

Background

Minimal change disease (MCD) and primary focal segmental glomerulosclerosis (FSGS) are glomerular diseases characterized by nephrotic syndrome. Their diagnosis requires a renal biopsy, but it is an invasive procedure with potential complications. In a small biopsy sample, where only normal glomeruli are observed, FSGS cannot be differentiated from MCD. The correct diagnosis is crucial to an effective treatment, as MCD is normally responsive to steroid therapy, whereas FSGS is usually resistant.

The purpose of our study was to discover and validate novel early urinary biomarkers capable to differentiate between MCD and FSGS.

Methods

Forty-nine patients biopsy-diagnosed of MCD and primary FSGS were randomly subdivided into a training set (10 MCD, 11 FSGS) and a validation set (14 MCD, 14 FSGS). The urinary proteome of the training set was analyzed by two-dimensional differential gel electrophoresis coupled with mass spectrometry. The proteins identified were quantified by enzyme-linked immunosorbent assay in urine samples from the validation set.

Results

Urinary concentration of alpha-1 antitrypsin, transferrin, histatin-3 and 39S ribosomal protein L17 was decreased and calretinin was increased in FSGS compared to MCD. These proteins were used to build a decision tree capable to predict patient’s pathology.

Conclusions

This preliminary study suggests a group of urinary proteins as possible non-invasive biomarkers with potential value in the differential diagnosis of MCD and FSGS. These biomarkers would reduce the number of misdiagnoses, avoiding unnecessary or inadequate treatments.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-017-0452-6) contains supplementary material, which is available to authorized users.

Quantification of bleeding volume using computed tomography and clinical complications after percutaneous renal biopsy

Background: The aim of this study was to investigate specific bleeding volume after percutaneous renal biopsy (PRB) and the correlation between bleeding volume and clinical parameters.

Methods: A retrospective study of 252 consecutive patients (153 male patients and 99 female patients) who underwent PRB at the Department of Nephrology, Japanese Red Cross Ishinomaki Hospital, between July 2013 and January 2016 was conducted. PRB was performed under ultrasound guidance using an automated spring-loaded biopsy device and a 16-cm, 16-gauge needle. Patients underwent computed tomography (CT) the day after PRB. Bleeding volume after PRB was evaluated using reconstructed CT data.

Results: The median bleeding volume after PRB was 38 mL (25th–75th percentile, 18–85 mL), with ≥4 punctures identified as a risk factor for massive bleeding. The incidence rates of macrohematuria, transient hypotension and bladder obstruction were 14.3, 8.7 and 4.7%, respectively. Post-PRB blood transfusion and intervention were required in 4.7 and 0.8% of patients, respectively.

Conclusion: Although it is difficult to assess the risk for massive bleeding prior to PRB, we do provide evidence of a specific increased risk with ≥4 puncture attempts, and recommend careful follow-up of these patients.

Absorption fever characteristics due to percutaneous renal biopsy-related hematoma

This study aims to describe the unique characteristics of absorption fever in patients with a hematoma after percutaneous renal biopsy (PRB) and distinguish it from secondary infection of hematoma.We retrospectively studied 2639 percutaneous renal biopsies of native kidneys. We compared the clinical characteristics between 2 groups: complication group (gross hematuria and/or perirenal hematoma) and no complication group. The axillary temperature of patients with a hematoma who presented with fever was measured at 06:00, 10:00, 14:00, and 18:00. The onset and duration of fever and the highest body temperature were recorded. Thereafter, we described the time distribution of absorption fever and obtained the curve of fever pattern.Of 2639 patients, PRB complications were observed in 154 (5.8%) patients. Perirenal hematoma was the most common complication, which occurred in 118 (4.5%) of biopsies, including 74 small hematoma cases (thickness ≤3 cm) and 44 large hematoma cases (thickness >3 cm). Major complications were observed in only 6 (0.2%) cases resulting from a large hematoma. Of 118 patients with a perirenal hematoma, absorption fever was observed in 48 cases. Furthermore, large hematomas had a 5.23-fold higher risk for absorption fever than the small ones.Blood pressure, renal insufficiency, and prothrombin time could be risk factors for complications. Fever is common in patients with hematoma because of renal biopsy and is usually noninfectious. Evaluation of patients with post-biopsy fever is necessary to identify any obvious infection sources. If no focus is identified, empiric antibiotic therapy should not be initiated nor should prophylactic antibiotics be extended for prolonged durations. Absorption fevers will resolve in time without specific therapeutic interventions.

Renal Medullary and Cortical Correlates in Fibrosis, Epithelial Mass, Microvascularity, and Microanatomy Using Whole Slide Image Analysis Morphometry

Renal tubulointerstitial injury often leads to interstitial fibrosis and tubular atrophy (IF/TA). IF/TA is typically assessed in the renal cortex and can be objectively quantitated with computerized image analysis (IA). However, the human medulla accounts for a substantial proportion of the nephron; therefore, medullary scarring will have important cortical consequences and may parallel overall chronic renal injury. Trichrome, periodic acid-Schiff (PAS), and collagen III immunohistochemistry (IHC) were visually examined and quantitated on scanned whole slide images (WSIs) (N = 67 cases). When tuned to measure fibrosis, IA of trichrome and Trichrome-PAS (T-P) WSIs correlated for all anatomic compartments (among cortex, medulla, and entire tissue, r = 0.84 to 0.89, P all <0.0001); and collagen III deposition correlated between compartments (r = 0.69 to 0.89, P <0.0001 to 0.0002); however, trichrome and T-P measures did not correlate with collagen deposition, suggesting heterogeneous contributions to extracellular matrix deposition. Epithelial cell mass (EPCM) correlated between cortex and medulla when measured with cytokeratin IHC and with the trichrome red portion (r = 0.85 and 0.66, respectively, all P < 0.0001). Visual assessment also correlated between compartments for fibrosis and EPCM. Correlations were found between increasing medullary inner stripe (IS) width and fibrosis in all of the tissue and the medulla by trichrome morphometry (r = 0.56, P < 0.0001, and r = 0.48, P = 0.00008, respectively). Weak correlations were found between increasing IS width and decreasing visual assessment of all tissue EPCM. Microvessel density (MVD) and microvessel area (MVA) measured using a MVD algorithm applied to CD34 IHC correlated significantly between all compartments (r = 0.76 to 0.87 for MVD and 0.71 to 0.87 for MVA, P all < 0.0001). Overall, these findings demonstrate the interrelatedness of the cortex and medulla and the importance of considering the renal parenchyma as a whole.

Renal biopsy: Still a landmark for the nephrologist

Renal biopsy was performed for the first time more than one century ago, but its clinical use was routinely introduced in the 1950s. It is still an essential tool for diagnosis and choice of treatment of several primary or secondary kidney diseases. Moreover, it may help to know the expected time of end stage renal disease. The indications are represented by nephritic and/or nephrotic syndrome and rapidly progressive acute renal failure of unknown origin. Nowadays, it is performed mainly by nephrologists and radiologists using a 14-18 gauges needle with automated spring-loaded biopsy device, under real-time ultrasound guidance. Bleeding is the major primary complication that in rare cases may lead to retroperitoneal haemorrhage and need for surgical intervention and/or death. For this reason, careful evaluation of risks and benefits must be taken into account, and all procedures to minimize the risk of complications must be observed. After biopsy, an observation time of 12-24 h is necessary, whilst a prolonged observation may be needed rarely. In some cases it could be safer to use different techniques to reduce the risk of complications, such as laparoscopic or transjugular renal biopsy in patients with coagulopathy or alternative approaches in obese patients. Despite progress in medicine over the years with the introduction of more advanced molecular biology techniques, renal biopsy is still an irreplaceable tool for nephrologists.

EULAR/ERA-EDTA recommendations for the management of ANCA-associated vasculitis

In this article, the 2009 European League Against Rheumatism (EULAR) recommendations for the management of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) have been updated. The 2009 recommendations were on the management of primary small and medium vessel vasculitis. The 2015 update has been developed by an international task force representing EULAR, the European Renal Association and the European Vasculitis Society (EUVAS). The recommendations are based upon evidence from systematic literature reviews, as well as expert opinion where appropriate. The evidence presented was discussed and summarised by the experts in the course of a consensus-finding and voting process. Levels of evidence and grades of recommendations were derived and levels of agreement (strengths of recommendations) determined. In addition to the voting by the task force members, the relevance of the recommendations was assessed by an online voting survey among members of EUVAS. Fifteen recommendations were developed, covering general aspects, such as attaining remission and the need for shared decision making between clinicians and patients. More specific items relate to starting immunosuppressive therapy in combination with glucocorticoids to induce remission, followed by a period of remission maintenance; for remission induction in life-threatening or organ-threatening AAV, cyclophosphamide and rituximab are considered to have similar efficacy; plasma exchange which is recommended, where licensed, in the setting of rapidly progressive renal failure or severe diffuse pulmonary haemorrhage. These recommendations are intended for use by healthcare professionals, doctors in specialist training, medical students, pharmaceutical industries and drug regulatory organisations.

HOW DO PATIENTS EXPERIENCE A KIDNEY BIOPSY?

BACKGROUND

Guidelines for care before, during and after a kidney biopsy vary nationally and internationally. A literature search has shown few studies about the care before, during and after a kidney biopsy and we found one study from the patients' perspective.

OBJECTIVES

The aim of the study is to gain knowledge about patients' experiences before, during and after a kidney biopsy.

METHODS

A qualitative study with a phenomenological and hermeneutic approach using 'observiews' of seven patients before, during and after a kidney biopsy. Data were analysed using Malterud's principles of systematic text condensation.

RESULTS

Three themes were found: The patients' basic needs, the patient's needs for information and the patients use humour as a coping strategy.

CONCLUSION AND APPLICATION TO PRACTICE

The patients' experiences were characterised by their need to fulfill self-care requirements, because they had to lie down for four to six hours after the biopsy procedure. There is a need to find evidence for the time the patient need to be bedbound to avoid bleeding complications. The patients' needs for information were different, which explains why information should be individualised. There is particular need for more information after discharge.

Beyond complications: Comparison of procedural differences and diagnostic success between nurse practitioners and radiologists performing image-guided renal biopsies

PURPOSE

Radiology-trained nurse practitioners (NPs) may perform image-guided medical renal biopsies with computed tomography (CT). This study evaluates the procedural differences and diagnostic success between biopsies performed by NPs compared to radiologists.

DATA SOURCES

A retrospective study was performed on patients who underwent nontargeted, CT-guided renal biopsy between 2009 and 2014. Provider type (NP or radiologist), number of core specimens obtained, sedation medication dose, CT dose index (CTDI), and diagnostic success were recorded. Categorical and continuous variables were analyzed using χ² and Student's two-tailed t-test, respectively, comparing NPs with radiologists.

CONCLUSIONS

A total of 386 patients were included; radiologists performed 215 biopsies and NPs performed 171 biopsies. There was no significant difference in diagnostic success, amount of tissue harvested (number of cores), radiation dose, or sedation dosage between NPs and radiologists performing CT-guided renal biopsies. Only 4% were nondiagnostic (n = 7, radiologists; n = 9, NPs; p = .325). Overall mean number of cores obtained was 3.7, mean CTDI was 176.5 mGy, mean fentanyl dose was 86.3 μg, and mean midazolam was dose 1.54 mg without a statistically significant difference between provider types.

IMPLICATIONS FOR PRACTICE

NPs perform image-guided medical renal biopsies in a similar fashion to radiologists with respect to diagnostic success, amount of tissue harvested, total radiation dose exposure, and administration of sedation.

Complications of Ultrasound-Guided Renal Transplant Biopsies

Renal transplant biopsies to diagnose transplant pathology are routinely performed using ultrasound guidance. Few large studies have assessed the rate and risk factors of major biopsy complications. This study is a single-center 5-year retrospective cohort analysis of 2514 biopsies. Major complications occurred in 47 of 2514 patients (1.9%) and included hospitalization, transfusion of blood products, operative exploration and interventional radiology procedures. The complication rate among "cause" biopsies was significantly higher than in "protocol" biopsies (2.7% vs. 0.33%, p < 0.001). Complications presented on postbiopsy days 0-14, with the majority diagnosed on the same day as the biopsy and manifested by hematocrit drop, although the presence of such delayed presentation of complications occurring >24 h after the biopsy on days 2-14 is previously unreported. Specific patient characteristics associated with increased risk of a complication were increased age and blood urea nitrogen, decreased platelet count, history of prior renal transplant, deceased donor transplant type and use of anticoagulant medications but not aspirin.

Image-guided intervention in the coagulopathic patient

Determining practice parameters for interventional procedures is challenging due to many factors including unreliable laboratory tests to measure bleeding risk, variable usage of standardized terminology for adverse events, poorly defined standards for administration of blood products, and the growing numbers of anticoagulant and antiplatelet medications. We aim to address these and other issues faced by radiologists performing invasive procedures through a review of available literature, and experiential guidance from three academic medical centers. We discuss the significant limitations with respect to using prothrombin-time and international normalized ratio to measure bleeding risk, especially in patients with synthetic defects due to liver function. Factors affecting platelet function including the impact of uremia; recent advances in laboratory testing, including platelet function testing; and thromboelastography are also discussed. A review of the existing literature of fresh-frozen plasma replacement therapy is included. The literature regarding comorbidities affecting coagulation including malignancy, liver failure, and uremia are also reviewed. Finally, the authors present a set of recommendations for laboratory thresholds, corrective transfusions, as well as withholding and restarting medications.

Positive trends in paediatric renal biopsy service provision in the UK: a national survey and re-audit of paediatric renal biopsy practice

BACKGROUND

Paediatric renal biopsy standards introduced in the UK in 2010 were intended to reduce variation and improve practice. A concurrent national drive was aimed at building robust paediatric nephrology networks to ensure services cater for the needs of the family and minimise time away from home. We aimed to identify current national practice since these changes on behalf of the British Association for Paediatric Nephrology.

METHODS

All UK paediatric nephrology centres were invited to complete a survey of their biopsy practice, including advance preparation. From 1 January to 30 June 2012, a national prospective audit of renal biopsies was undertaken at participating centres comparing practice with the British Association for Paediatric Nephrology (BAPN) standards and audit results from 2005.

RESULTS

Survey results from 11 centres demonstrated increased use of pre-procedure information leaflets (63.6 % vs 45.5 %, P = 0.39) and play preparation (90.9 % vs 9.1 %, P = 0.0001). Audit of 331 biopsies showed a move towards day-case procedures (49.5 % vs 32.9 %, P = 0.17) and reduced major complications (4.5 % vs 10.4 %, P = 0.002). Biopsies with 18-gauge needles had significantly higher mean pass rates (3.2 vs 2.3, P = 0.0008) and major complications (15.3 % vs 3.3 %, P = 0.0015) compared with 16-gauge needles.

CONCLUSIONS

Percutaneous renal biopsy remains a safe procedure in children, thus improving family-centered service provision in the UK.

Incidence of bleeding complications after percutaneous core needle biopsy in hypertensive patients and comparison to normotensive patients

PURPOSE

To retrospectively determine the rate of major bleeding complications after solid organ or lung biopsy in patients with hypertension and compare to the rates of bleeding in normotensive patients.

MATERIALS AND METHODS

Following IRB approval, retrospective review of all solid organ and lung biopsies performed at our institution between June 1st, 2013 and October 31st, 2015 was performed. Hypertension was defined as a maximum observed systolic blood pressure of 160 mmHg or greater and/or diastolic blood pressure of 90 mmHg or greater at the time of the biopsy procedure. Bleeding complications were defined using the Common Terminology Criteria for Adverse Events (CTCAE, version 4.0) established by the National Cancer Institute.

RESULTS

4756 total biopsies in 3876 unique patients (median age 60, 57% male) were included. 1488 (31.3%) of these biopsies were performed in hypertensive patients. Fifteen major hemorrhages (CTCAE grade 3 or higher) occurred (0.32%). There were no deaths. There was no significant association between hypertension and major bleeding. The incidence of bleeding in hypertensive patients was 0.40% (6/1488), which was not statistically different than the incidence in normotensive patients (9/3268, 0.28%, p = 0.496). For the subgroup of native renal parenchymal biopsies, the rate of bleeding was slightly higher in hypertensive patients (3/213, 1.4% vs. 1/355, 0.28% in normotensive patients) but remained low, and the difference was not statistically significant (p = 0.188).

CONCLUSION

The overall incidence of major bleeding after percutaneous biopsy is very low. Hypertension does not appear to significantly increase the risk of major bleeding complications.

Current Safety of Renal Allograft Biopsy With Indication in Adult Recipients: An Observational Study

Renal biopsy remains the golden standard diagnosis of renal function deterioration. The safety in native kidney biopsy is well defined. However, it is a different story in allograft kidney biopsy. We conduct this retrospective study to clarify the safety of allograft kidney biopsy with indication.All variables were grouped by the year of biopsy and they were compared by Mann-Whitney U test (for continuous variables) or Chi-square test (for categorical variables). We collected possible factors associated with complications, including age, gender, body weight, renal function, cause of uremia, status of coagulation, hepatitis, size of needle, and immunosuppressants.We recruited all renal transplant recipients undergoing allograft biopsy between January of 2009 and December of 2014. This is the largest database for allograft kidney biopsy with indication. Of all the 269 biopsies, there was no difference in occurrence among the total 14 complications (5.2%) over these 6 years. There were only 3 cases of hematomas (1.11%), 6 gross hematuria (2.23%), 1 hydronephrosis (0.37%), and 2 hemoglobin decline (0.74%). The outcome of this cohort is the best compared to all other studies, and it is even better than the allograft protocol kidney biopsy. Among all possible factors, patients with pathological report containing "medullary tissue only" were susceptible to complications (P < 0.001, 1.8 of relative risk).In modern era, this study demonstrates the safety of allograft kidney biopsy with indication. Identifying the renal capsule before biopsy to avoid puncture into medulla is the most important element to prevent complications.

Clinical factors influencing the decision to transfuse after percutaneous native kidney biopsy

Background

Transfusion of erythrocytes is the most common intervention after a complicated percutaneous renal biopsy (PRB). Anemia is considered to be a leading risk factor for bleeding following a PRB, and based on recent studies of transfusions in hospitalized patients, many institutions are restricting the threshold for erythrocyte transfusion to a lower hemoglobin concentration (Hgb). The purpose of this study is to analyze factors that influence the transfusion decision after a PRB, and to determine whether anemia is truly a risk factor for bleeding or anemic patients are simply more likely to receive a transfusion because of their already lower pre-PRB Hgb.

Methods

PRB of native kidneys was performed using real-time ultrasound with automated biopsy needles from January 1990 to April 2014. All patients were prospectively followed for bleeding with a 24-h inpatient observation. An intervention for a bleeding complication (BL-I) was defined by undergoing a procedure (cystoscopy, embolization), receiving a blood transfusion (BL-T), death and/or readmission related to the biopsy. To further define the effect of anemia, patients were divided into three pre-PRB Hgb groups: <9.0 g/dL (n = 79), 9.0–11.0 g/dL (n = 266) and >11.0 g/dL (n = 565).

Results

BL-I occurred in 71/910 (7.8%) of PRBs. The majority of these were BL-T (57/71, 80%; 57/910, 6.3% overall). Patients with BL-I had lower pre-PRB Hgb than those without BL-I (mean ± SD; 10.3 ± 2.0 versus 12.0 ± 2.1 g/dL, P < 0.0001) and a greater change (Δ) in Hgb (2.1 ± 1.6 versus 1.0 ± 0.8 g/dL, P < 0.0001). When compared with higher Hgb, patients with Hgb <9.0 g/dL had more traditional risk factors for bleeding (older age: 49 ± 18 versus 48 ± 18 versus 45 ± 16 years, P = 0.02; female: 72 versus 70 versus 56%, P < 0.0001; higher serum creatinine: 4.0 ± 2.9 versus 2.9 ± 2.6 versus 1.7 ± 1.4 mg/dL, P < 0.0001; higher systolic blood pressure: 138 ± 18 versus 133 ± 19 versus 133 ± 18 mmHg, P = 0.06; higher bleeding time: 7.6 ± 1.8 versus 7.4 ± 2.0 versus 6.7 ± 1.8 min, P < 0.0001). When BL-T was stratified by pre-PRB Hgb, there were more transfusions in those with lower pre-PRB Hgb (24 versus 9 versus 3%, P < 0.0001). However, these patients not only had fewer hematomas (58 versus 83 versus 87%, P = 0.04) but also demonstrated a smaller ΔHgb post-PRB (1.3 ± 1.0 versus 1.8 ± 0.8 versus 3.2 ± 1.6, P < 0.0001) compared with patients with higher pre-PRB Hgb, yet still received a transfusion.

Conclusions

While patients with lower pre-PRB Hgb have more of the traditional risk factors for a complication after PRB, there was actually less clinically evident bleeding in these patients who were transfused. Although anemia itself has been considered to be a risk factor for a complication in the past, it more accurately represents only a predictor of receiving an erythrocyte transfusion. In the setting of the PRB, the decision for transfusion is influenced more by the severity of anemia at baseline as opposed to clinically evident bleeding.

Renal transplant ultrasound: The nephrologist's perspective

One of the principal roles of a nephrologist is to closely monitor renal transplant allograft function and promptly evaluate any dysfunction. Renal transplant sonography has a major role in this assessment process given its ability to easily define renal transplant anatomy and surrounding structures. Abnormalities can be extrarenal or involve vascular, parenchymal and urological components of the graft and these can acutely or chronically influence graft function and survival. Procedural guidance as is required during allograft biopsy, as well as routine surveillance and screening for post transplant complications such as malignancy are also important applications of ultrasound in the management of renal transplant recipients. This article outlines key ultrasound findings and applications in renal transplantation from the clinician's perspective.

The Native Kidney Biopsy: Update and Evidence for Best Practice

The kidney biopsy is the gold standard in the diagnosis and management of many diseases. Since its introduction in the 1950s, advancements have been made in biopsy technique to improve diagnostic yield while minimizing complications. Here, we review kidney biopsy indications, techniques, and complications in the modern era. We also discuss patient populations in whom special consideration must be given when considering a kidney biopsy and the important role that the kidney biopsy plays in nephrology training. These data are presented to develop best practice strategies for this essential procedure.

Endovascular embolization of pseudoaneurysm of left colic artery developing after renal biopsy

Vascular complications after percutaneous renal biopsy are uncommon and may require interventional management. In most of these cases, the pathology is a renal arterial pseudoaneurysm (PsA) or an arterio-venous fistula. Injury to other vessels like aorta, lumbar arteries or mesenteric arteries is rare with only one case of left colic artery PsA reported in literature. We report a case of a 60-year-old female, who developed left colic artery PsA after renal biopsy, which was successfully embolized through endovascular route using microcoils.

Incidence of A-V Fistulas after Renal Biopsy of Native and Transplanted Kidney - Two Centers Experience

AIM:

The aim of the study is to make a retrospective analysis of the incidence of AV fistulas after renal biopsy (RB) of native and transplanted kidney.

MATERIALS AND METHODS:

Five hundred and sixteen (516) RB were analyzed. One hundred twenty nine (129) were native kidneys RB performed in Clinic of Nephrology (CN), 190 were performed in Clinic of Nephrology and transplantation (CNT) and 197 were transplanted kidney biopsies from the same clinic. Biopsy technique type Gun with needle 14G, 16 and 18 G was used in CN, CNT used the same technique with needles 16G. Doppler ultrasound was made for A-V fistulas diagnosis.

RESULTS:

The A-V fistulas incidence was 0.8%. The frequency of A-V fistulas registered in CN was significantly higher than that registered in CNT (2.3% vs. 0.5%, p < 0.01). Biopsies performed by 14 G needles provide a higher percentage of A-V fistulas compared to those done by 16 G. (3.3% vs. 2.4%, p < 0.5). The frequency of the A-V fistulas in native and transplanted kidneys in CNT was similar (0.5% vs. 0.5%, p > 0.05).

CONCLUSION:

The A-V fistulas incidence is very low. The needle thickness is an important factor relevant to the risk of occurrence of A-V fistulas.

Evaluating renal biopsy-associated hemorrhage complications by the equation and providing an early intervention: a single-center experience

BACKGROUND

The aim was to evaluate the risk for major hemorrhage complications (MHC) prior to percutaneous renal biopsy and apply a specific procedure in high-risk patients to decrease their incidence. Hemorrhage complications that required blood transfusion or other interventions were diagnosed as MHC.

METHODS

One retrospective (Group A, n = 1314) and two prospective cohorts (Group B, n = 249 and Group C, n = 422) were involved in the study. Group A was used to establish a risk equation for MHC, Group B to test its performance, and Group C to evaluate the efficacy of the proposed procedure to reduce MHC incidence. Group C was classified, based on the equation, into high-risk (C1) and low-risk (C2) patients, who received different interventions. The intervention in Group C1 consisted of use of 18-gauge needles, a 12-h rest period post-operation, and reptilase injection; in Group C2, 16-gauge needles were used, with a 6-h rest, and no reptilase injection. Group B was also divided into B1 (high-risk) and B2 (low-risk) using the same cut-off, for further comparison.

RESULTS

(1) In Group A, 4.8% of patients experienced MHC and the equation: Logit (PMHC) = 0.022 × mean arterial pressure (mmHg) + 0.216 × bleeding time (min) - 0.011 × eGFR [ml/(min 1.73 m(2))] - 0.894 × kidney length (cm) - 2.100 × renal cortical thickness (cm) + 6.225 (cutoff = -1.664) was established. (2) The area under the receiver operating characteristic curve was 0.848 (95 % CI 0.797-0.890) for Group B. (3) MHC occurred in 4.8 and 2.8% of patients in Group B and C, respectively; Group B1 suffered significantly more frequent gross hematuria, hematoma and MHC than Group C1; however, no significant difference except for large hematoma was found between Groups B2 and C2 for all complications.

CONCLUSIONS

The equation is reliable to predict the risk for MHC; the interventions proposed can decrease the incidence of MHC in high-risk patients.

Safety of paediatric percutaneous native kidney biopsy and factors predicting bleeding complications

AIM

Data on safety of paediatric percutaneous native kidney biopsy (PNKB) using automated biopsy devices and real-time ultrasonography are lacking. The objective of this study was to evaluate the safety and to identify factors predicting bleeding complications associated with this PNKB protocol.

METHODS

A total of 227 patients aged <18 years who underwent the first PNKB were analyzed. The primary outcome was bleeding complications divided into minor and major bleeding complications. Minor bleeding complications included perirenal haematoma and macroscopic haematuria. Major bleeding complications included requirement of blood transfusion, a higher level of care or vasopressors to maintain haemodynamic stability, requirement of angiographic or surgical intervention, or death.

RESULTS

Perirenal haematoma occurred in 58 patients (25%) and macroscopic haematuria occurred in 46 patients (20%). Two factors were independently associated with perirenal haematoma in a multivariate model. These were male gender and weight for height Z-score <-0.5. Three patients (1.3%), all with perirenal haematoma had major bleeding complications (two required blood transfusion and one underwent surgery to repair an injured renal artery).

CONCLUSIONS

The favourable safety information from our study is useful when counselling the parents and patients undergoing similar protocols. PNKB can be safely performed when precautions are taken to prevent bleeding. Selection of biopsy instruments should be tailored according to patient size.

Real-time ultrasound-guided percutaneous renal biopsy with needle guide by nephrologists decreases post-biopsy complications

Background

Percutaneous renal biopsy (PRB) can result in serious complications. The study is aimed to compare the biopsy yield and complications rate of the real-time ultrasonagram (USG)-guided PRB and needle tracking with and without needle guide in two different study periods.

Methods

We compared the yield and complications of 2138 kidney biopsies performed in two different periods, 1510 biopsies during the first period from April 2004–December 2010 and 628 biopsies during second period from January 2011–March 2013. All biopsies in both periods were performed by nephrologists. Radiologists provided the real-time image without needle guide during the first period while nephrologists performed both imaging and biopsy with needle guide during the second period.

Results

Of all the 2138 patients, 226 (10.5%) patients developed 118 minor and 108 major complications. Only 13 (2.1%) major complications occurred in the second period and 95 (6.7%) in the first period (P < 0.001). The relative risk of developing a major complication without guide was 3.04 times greater than that of the biopsies performed with use of the guide. The mean number of glomeruli per biopsy obtained during the second period (17.98 ± 6.75) was significantly greater than that of the first period (14.14 ± 6.01) (P = 0.004). The number of passes to acquire adequate tissue (P = 0.001) and percentage of cortex on biopsy (P = 0.001) were also significantly better in the second period. The optimal observation period post biopsy is 24 h.

Conclusions

Real-time USG imaging supported by needle guide device is associated with better biopsy yield and fewer complications.

Successful Detection of Renal Involvement in Sjögren's Syndrome Secondary to Systemic Lupus Erythematosus by Renal Biopsy

An 80-year-old man presented with a mildly decreased renal function and increased anti-double-stranded-DNA (anti-dsDNA) antibody levels, and met the diagnostic criteria of the American College of Rheumatology for systemic lupus erythematosus (SLE). However, the incremental increase in creatinine levels and the mild proteinuria were inconsistent with lupus nephritis. We performed a renal biopsy, which revealed interstitial nephritis and minor glomerular abnormalities. Further examinations determined that the renal lesion was due to Sjögren's syndrome secondary to SLE. Following treatment with oral prednisolone, the patient's renal function improved as his anti-dsDNA antibody levels decreased. This case report indicates that renal biopsy should be considered even in elderly individuals when it may assist in the diagnosis, treatment, and prognosis of the patient.

A clinicopathological study of renal biopsies from 288 elderly patients: analysis based on 4,185 cases

PURPOSE

To investigate the clinical characteristics and histopathological features of kidney disease in elderly patients.

METHODS

We retrospectively analyzed the results of 4,185 consecutive renal biopsies, and 288 patients aged >60 years at the Second Hospital of Jilin University from January 1998 to December 2013 were finally included. All patients had been clinically and histologically diagnosed with kidney disease.

RESULTS

Nephrotic syndrome was the main clinical indication for biopsy. Twenty-four patients (8.33 %) experienced a minor complication related to their biopsy procedure. Among patients diagnosed as primary glomerulonephritis (GN), membranous nephropathy (MN) was the most frequent subclassification (24.7 %), followed by mesangioproliferative glomerulonephritis (MsPGN, 11.1 %) and IgA nephropathy (IgAN, 8.0 %). Amyloidosis (8.7 %) was the most common secondary GN, followed by antineutrophil cytoplasmic autoantibody (ANCA)-associated pauci-immune GN (5.2 %) and diabetic nephropathy (DN, 3.8 %). Based on renal biopsies results, 143/288 patients received immunosuppressive therapy and showed an overall remission rate (complete plus partial remissions) of 74.1 %. Among 71 MN patients, 29 patients received steroids plus cyclophosphamide and showed a remission rate of 79.3 %, while 42 patients received steroids and tacrolimus and showed a remission rate of 90.5 %. Among 25 patients with amyloidosis, 22 cases received melphalan plus dexamethasone and showed a remission rate of 40.9 %, while three patients received vincristine, adriamycin, and dexamethasone and showed a remission rate of 66.7 %.

CONCLUSION

Making an accurate pathologic diagnosis by renal biopsy is crucial for selecting the proper treatment for elderly patients with kidney disease.

Renal biopsy practice: What is the gold standard?

Renal biopsy (RB) is useful for diagnosis and therapy guidance of renal diseases but incurs a risk of bleeding complications of variable severity, from transitory haematuria or asymptomatic hematoma to life-threatening hemorrhage. Several risk factors for complications after RB have been identified, including high blood pressure, age, decreased renal function, obesity, anemia, low platelet count and hemostasis disorders. These should be carefully assessed and, whenever possible, corrected before the procedure. The incidence of serious complications has become low with the use of automated biopsy devices and ultrasound guidance, which is currently the “gold standard” procedure for percutaneous RB. An outpatient biopsy may be considered in a carefully selected population with no risk factor for bleeding. However, controversies persist on the duration of observation after biopsy, especially for native kidney biopsy. Transjugular RB and laparoscopic RB represent reliable alternatives to conventional percutaneous biopsy in patients at high risk of bleeding, although some factors limit their use. This aim of this review is to summarize the issues of complications after RB, assessment of hemorrhagic risk factors, optimal biopsy procedure and strategies aimed to minimize the risk of bleeding.

A study of clinical complications and risk factors in 1,001 native and transplant kidney biopsies in Sweden

BACKGROUND

In Sweden, native and transplant kidney biopsies are usually performed in major renal medical centers.

PURPOSE

To clarify risk factors in native and transplant kidney biopsies to improve patient safety.

MATERIAL AND METHODS

A total of 1001 biopsies (in 352 women and 565 men) were included. The median age was 54 years (range, 16-90 years). Data were derived from 826 native kidney biopsies (640 prospective and 186 retrospective) and 175 transplant kidney biopsies (170 prospective and 5 retrospective). Various factors and complications were registered while performing native and transplant kidney biopsies, focusing on major (e.g. blood transfusions, invasive procedures) and minor complications. The prospective protocol was used at six centers and at one center data were obtained retrospectively.

RESULTS

Women were at greater risk of overall complications than men (12.2% vs. 6.5%; P = 0.003; odds ratio [OR], 2.0; confidence interval [CI], 1.3-3.1) as well as of major complications (9.6% vs. 4.5%; P = 0.002; OR, 2.2, CI 1.3-3.7). Major complications occurred more commonly after biopsies from the right kidney, in women than in men (10.8% vs. 3.1%; P = 0.005; OR, 3.7; CI, 1.5-9.5), and in patients with lower BMI (25.5 vs. 27.3, P = 0.016) and of younger age (45 years vs. 52.5 years; P = 0.001). Lower mean arterial pressure in transplant kidney biopsies indicated a risk of major complications (90 mmHg vs. 98 mmHg; P = 0.039). Factors such as needle size, number of passes, serum creatinine, and eGFR did not influence complication rates.

CONCLUSION

The present findings motivate greater attention being paid to the risk of major side-effects after right-side biopsies from women's kidneys, as well as after biopsies from younger patients and patients with lower BMI.

Factors that can minimize bleeding complications after renal biopsy

Renal biopsy is a very important diagnostic tool in the evaluation of renal diseases. However, bleeding remains to be one of the most serious complications in this procedure. Many new techniques have been improved to make it safer. The risk factors and predictors of bleeding after percutaneous renal biopsy have been extensively reported in many literatures, and generally speaking, the common risk factors for renal biopsy complications focus on hypertension, high serum creatinine, bleeding diatheses, amyloidosis, advanced age, gender and so on. Our primary purpose of this review is to summarize current measures in recent years literature aiming at minimizing the bleeding complication after the renal biopsy, including the drug application before and after renal biopsy, operation details in percutaneous renal biopsies, nursing and close monitoring after the biopsy and other kinds of biopsy methods.

Preeclampsia before 20 weeks of gestation: a case report and review of the literature

The occurrence of preeclampsia before 20 weeks of gestation is rare and usually associated with trophoblastic diseases or antiphospholipid syndrome. Here, we report a case of preeclampsia before 20 weeks of gestation in the absence of the aforementioned disorders. A healthy 30-year-old nulliparous woman presented with new onset of hypertension and proteinuria at 18 weeks of gestation. Fetal ultrasound did not reveal any abnormalities. Empirical steroid treatment was initiated based on a tentative diagnosis of underlying renal disease. The clinical course of the disease was progressive despite steroid treatment and the fetus died in utero 8 days after the initiation of treatment. Following delivery, a renal biopsy was performed and provided a diagnosis of preeclampsia. All symptoms resolved postpartum. This report demonstrates that preeclampsia may occur before 20 weeks of gestation and should always be considered in the differential diagnosis of pregnant women with new onset of hypertension with proteinuria. Previous published cases are summarized briefly.

Safety and tissue yield for percutaneous native kidney biopsy according to practitioner and ultrasound technique

Background

Although percutaneous renal biopsy remains an essential tool in the diagnosis and treatment of renal diseases, in recent times the traditional procedure of nephrologists has been performed by non-nephrologists rather than nephrologists at many institutions. The present study assessed the safety and adequacy of tissue yield during percutaneous renal biopsy according to practitioners and techniques based on ultrasound.

Methods

This study included 658 native renal biopsies performed from 2005 to 2010 at a single centre. The biopsies were performed by nephrologists or expert ultrasound radiologists using the ultrasound-marked blind or real-time ultrasound-guided techniques.

Results

A total of 271 ultrasound-marked blind biopsies were performed by nephrologists, 170 real-time ultrasound-guided biopsies were performed by nephrologists, and 217 real-time ultrasound-guided biopsies were performed by radiologists during the study period. No differences in post-biopsy complications such as haematoma, need for transfusion and intervention, gross haematuria, pain, or infection were observed among groups. Glomerular numbers of renal specimens from biopsies performed by nephrologists without reference to any technique were higher than those obtained from real-time ultrasound-guided biopsies performed by expert ultrasound radiologists.

Conclusions

Percutaneous renal biopsy performed by nephrologists was not inferior to that performed by expert ultrasound radiologists as related to specimen yield and post-biopsy complications.

Relationship between hospital volume and hemorrhagic complication after percutaneous renal biopsy: results from the Japanese diagnosis procedure combination database

BACKGROUND

Although hemorrhagic complications are major complications of percutaneous renal biopsy (PRB), the relationship between procedure volume and morbidity remains unclear for PRB. The present study investigated the impact of hospital volume on the occurrence of hemorrhagic complications after PRB.

METHODS

Using large claims-based data in the diagnosis procedure combination database in Japan, we identified inpatients with renal disorders who underwent PRB within 4 days after admission during July to December 2007 to 2010. We assessed patient age, sex, clinical syndromes, hemorrhagic complications and diagnoses, and annual hospital volume of PRB divided into quintiles. Multivariate logistic regression analyses fitted with a generalized estimation equation were performed accounting for within-hospital clustering.

RESULTS

A total of 15,191 patients were identified from 942 hospitals. The overall proportion of hemorrhagic complications was 2.1 %, including diagnoses of hemorrhagic events (1.6 %), red blood cell transfusion (0.5 %), and requiring angiography or endovascular procedure (0.1 %). In-hospital deaths attributable to the complications occurred in 0.06 % of the patients. Patients with rapidly progressive nephritic syndrome (odds ratio 3.41, 95 % confidence interval 2.22-5.25) had significantly higher incidence than those with chronic nephritic syndrome. No significant association was observed between hospital volume and hemorrhagic complications, with odds ratios for the low-intermediate, intermediate, intermediate-high, and high-volume groups relative to the low-volume group of 0.74 (0.43-1.26), 1.19 (0.74-1.92), 1.16 (0.67-2.00), and 1.35 (0.78-2.34), respectively.

CONCLUSIONS

No significant relationship was observed between hemorrhagic complication incidence and hospital volume regarding PRB.

[Biopsies of the kidney, prostate and urinary bladder]

BACKGROUND

Biopsies of the kidney, prostate and urinary bladder are amongst the most frequent interventions in urology. A correct indication, preparation and performance are important to achieve good results and low complication rates.

OBJECTIVES

In this review complication management in biopsies of the kidney, prostate and urinary bladder are discussed.

MATERIALS AND METHODS

A selective search of the literature, with emphasis on systematic reviews and larger cohort studies was performed.

RESULTS

Complication rates are generally low. However, certain factors such as coagulation disorders, anatomical malformations, accompanying morbidities or antibiotic resistance may play a significant role and increase rates of complications. Especially complications such as hematuria and injury of contiguous organs are described in the literature.

DISCUSSION

Biopsies of the kidney, prostate and urinary bladder can be performed with low complication rates if general and specific factors in the planning of the intervention and prevention of complications are considered.

Risk factors and timing of native kidney biopsy complications

Background

The appropriate observation period, rate and risk factors of complications after a percutaneous renal biopsy remain debated.

Methods

We retrospectively studied native kidney biopsies performed in our institution between January 2007 and July 2011. Outpatients had either an 8- (67%) or a 24-hour (33%) observation period.

Results

312 biopsies were reviewed (287 patients), 51% of patients were female and the mean age was 54 ± 15 years. Half of these biopsies were performed in outpatients. A total of 15% of patients developed a symptomatic hematoma, 9% received a red blood cell transfusion and 1% required an angio-intervention. Eighty-four percent of the complications manifested within the first 8 h, 86% at 12 h and 94% at 24 h. Outpatients experienced significantly less complications, all manifesting within the first 8 h, 14% required an observation period longer than planned. The risk of symptomatic hematoma increased to 11, 20, 35 and 40% in patients with >200, 140-200, 100-140 and <100 × 10⁹/l platelets, respectively (p = 0.002). It also increased in hemodialysis patients (29% compared to 14%, p = 0.02). We found no association of risk with the number of biopsy passes and only a trend with needle size.

Conclusion

Symptomatic hematomas occurred in 15% of kidney biopsies and were strongly associated with platelet count and hemodialysis. Outpatients experienced fewer complications; therefore, we can conclude that same-day discharge in selected patients is safe.

Urinary peptide profiling to differentiate between minimal change disease and focal segmental glomerulosclerosis

BACKGROUND

Minimal change disease (MCD) and primary focal segmental glomerulosclerosis (FSGS) are the main causes of primary idiopathic nephrotic syndrome in children and adults, with diagnosis being essential for the appropriate choice of therapy and requiring renal biopsy. However, the presence of only normal glomeruli on renal biopsy of FSGS patients may lead to the misclassification of these patients as having MCD. The aim of this study was to (i) compare the peptide profile of MCD and FSGS patients with that of a group of healthy subjects, (ii) generate and validate a class prediction model to classify MCD and FSGS patients and (ii) identify candidate biomarkers of these glomerular entities by analysis of the urinary peptidome.

METHODS

The urinary peptide profile was analyzed by magnetic bead-based technology combined with MALDI-TOF mass spectrometry in 44 patients diagnosed of MCD (n = 22) and FSGS (n = 22). The resulting spectra were compiled and analyzed using ClinProTools software.

RESULTS

A class prediction model was developed to differentiate MCD and FSGS patients. The validation of this model correctly classified 81.8% (9/11) of MCD patients and 72.7% (8/11) of FSGS patients. Moreover, the signal with m/z 1913.60, identified as a fragment of uromodulin, and the signal with m/z 2392.54, identified as a fragment of alpha-1-antitrypsin, showed higher and lower peak areas, respectively, in FSGS patients compared with MCD patients.

CONCLUSIONS

The simple, non-invasive technique described in the present study may be a useful tool to help clinicians by confirming diagnoses achieved by renal biopsy, thereby reducing misdiagnoses and avoiding the implementation of inappropriate therapies.

Utility of renal biopsy in the clinical management of renal disease

Characterizing chronic kidney disease (CKD) at all stages is an essential part of rational management and the renal biopsy plays a key role in defining the processes involved. There remain no global guidelines available to the renal community on indications for this important diagnostic, prognostic, and relatively safe test. Although most nephrologists recognize several clear indications for a renal biopsy, it is still underutilized. It not only helps the clinician to manage the patient with CKD, but it can also help clarify the epidemiology of CKD, and aid research into the pathobiology of disease with the aim of discovering new therapies. It may be useful for instance in elderly patients with CKD, those with diabetes and presumed 'hypertensive nephropathy', and in some patients with advanced CKD as part of the pretransplant work-up. In some populations (for example, immunoglobulin A nephropathy and ANCA vasculitis), renal biopsy allows disease classification that may predict CKD progression and response to therapy. For the individual, interval renal biopsy may be of use in providing ongoing therapeutic and prognostic information. Molecular advances will change the landscape of renal pathology and add a new dimension to the diagnostic precision of kidney biopsy. Organizing the multiplicity of information available in a renal biopsy to maximize benefits to the patient, as well as to the epidemiologist and researcher, is one of the challenges that face the nephrology community.

A case of arteriovenous fistula after renal biopsy in an IgA nephropathy patient with macroscopic hematuria

Macroscopic hematuria is a common symptom in IgA nephropathy and is also one of the most frequent complications after a percutaneous renal biopsy. Here, we describe a patient with IgA nephropathy and recurrent macroscopic hematuria who developed an arteriovenous fistula after renal biopsy.