Underwent Kidney Biopsy Research Articles

Age of Onset and Disease Course in Biopsy-Proven Minimal Change Disease: An Analysis From the Cure Glomerulonephropathy Network

Adolescent- and adult-onset minimal change disease (MCD) may have a clinical course distinct from childhood-onset disease. We characterized the course of children and adults with MCD in the Cure Glomerulonephropathy Network (CureGN) and assessed predictors of rituximab response. Prospective, multicenter, observational study. CureGN participants with proven MCD on biopsy. Age at disease onset, initiation of renin-angiotensin-aldosterone system (RAAS) blockade, and immunosuppression including rituximab during the study period. Relapse and remission, change in estimated glomerular filtration rate (eGFR), and kidney failure. Remission and relapse probabilities were estimated using Kaplan-Meier curves and gap time recurrent event models. Linear regression models were used for the outcome of change in eGFR. Cox proportional hazards models were used to estimate the association between rituximab administration and remission. The study included 304 childhood- (≤12 years old), 49 adolescent- (13-17 years old), and 201 adult- (≥18 years) onset participants with 2.7-3.2 years of follow-up after enrollment. Children had a longer time to biopsy (238 vs 23 and 36 days in adolescent- and adult-onset participants, respectively; P<0.001) and were more likely to have received therapy before biopsy. Children were more likely to be treated with immunosuppression but not RAAS blockade. The rate of relapse was higher in childhood- versus adult-onset participants (HR, 1.69 [95% CI, 1.29-2.21]). The probability of remission was also higher in childhood-onset disease (HR, 1.33 [95%CI, 1.02-1.72]). In all groups eGFR loss was minimal. Children were more likely to remit after rituximab than those with adolescent- or adult-onset disease (adjusted HR, 2.1; P=0.003). Across all groups, glucocorticoid sensitivity was associated with a greater likelihood of achieving complete remission after rituximab (adjusted HR, 2.62; P=0.002). CureGN was limited to biopsy-proven disease. Comparisons of childhood to nonchildhood cases of MCD may be subject to selection bias, given that childhood cases who undergo a biopsy may be limited to patients who are least responsive to initial therapy. Among patients with MCD who underwent kidney biopsy, there were differences in the course (relapse and remission) of childhood-onset compared with adolescent- and adult-onset disease, as well as rituximab response. Minimal change disease is a biopsy diagnosis for nephrotic syndrome. It is diagnosed in childhood, adolescence, or adulthood. Patients and clinicians often have questions about what to expect in the disease course and how to plan therapies. We analyzed a group of patients followed longitudinally as part of the Cure Glomerulonephropathy Network (CureGN) and describe the differences in disease (relapse and remission) based on the age of onset. We also analyzed rituximab response. We found that those with childhood-onset disease had a higher rate of relapse but also have a higher probability of reaching remission when compared with adolescent- or adult-onset disease. Children and all steroid-responsive patients are more likely to achieve remission after rituximab.

Risk and Timing of Major Bleeding Complications Requiring Intervention of the Percutaneous Kidney Biopsy With a Short Observation Protocol: A Retrospective Chart Review

Background: We previously published a retrospective study of kidney biopsies performed in a tertiary care hospital in London, Ontario from 2012 to 2017. This study resulted in a change of practice in our institution to shorter postbiopsy monitoring for outpatients as well as the development of a risk calculator to predict serious bleeding complications. Objective: The primary objective of this study was to determine whether this shorter monitoring time is adequate in the outpatient setting. A secondary objective was to validate the bleeding risk calculator in both inpatients and outpatients. Design: This was a retrospective chart review. Setting: This study was performed at a tertiary academic hospital in London, Ontario, Canada. Participants: This was a retrospective study of 400 adult patients who underwent kidney biopsy between April 30, 2018 and February 25, 2022 at a tertiary academic hospital in London, Canada. Methods: We retrospectively assessed frequency and timing of major bleeding complications in patients who underwent kidney biopsy. In secondary analyses, we examined the prediction performance of the risk calculator in discrimination and calibration. Results: Major bleeding occurred in 7 patients (1.8%). Five of these patients required blood transfusions (1.3%) and 2 required embolization (0.5%). In the outpatient setting, any major bleeding events were identified immediately (1 patient) or on the routine 2-hour ultrasounds (1 patient). The risk calculator showed good discrimination (C-statistic, 0.91, 95% confidence interval [CI] = [0.84 to 0.95]) and calibration (slope, 1.10, 95% CI = [0.47 to 1.74]; intercept, 95% CI = −0.02 [−0.79 to 0.75]), but with much uncertainty in the estimates. Limitations: The occurrence of only a few major bleeding events limits the reliability of our assessment of our risk calculator. Conclusions: There appears to be little yield in extending observation beyond 2 hours after an outpatient kidney biopsy with the use of immediate and 2-hour postbiopsy ultrasounds. The bleeding risk calculator ( http://perioperativerisk.com/kbrc ) warrants further validation.

Oxalate Nephropathy.

Oxalate Nephropathy.

The Development of a Comprehensive Clinicopathologic Registry for Glomerular Diseases Using Natural Language Processing.

Glomerulonephritis (GN) represents a common cause of chronic kidney disease, and treatment to slow or prevent progression of GN is associated with significant morbidity. Large patient registries have improved the understanding of risk stratification, treatment selection, and definitions of treatment response in GN, but can be resource-intensive, with incomplete patient capture. To describe the creation of a comprehensive clinicopathologic registry for all patients undergoing kidney biopsy in Manitoba, using natural language processing software for data extraction from pathology reports, as well as to describe cohort characteristics and outcomes. Retrospective population-based cohort study. Tertiary care center in the province of Manitoba. All patients undergoing a kidney biopsy in the province of Manitoba from 2002 to 2019. Descriptive statistics are presented for the most common glomerular diseases, along with outcomes of kidney failure and mortality for the individual diseases. Data from native kidney biopsy reports from January 2002 to December 2019 were extracted into a structured database using a natural language processing algorithm employing regular expressions. The pathology database was then linked with population-level clinical, laboratory, and medication data, creating a comprehensive clinicopathologic registry. Kaplan-Meier curves and Cox models were constructed to assess the relationship between type of GN and outcomes of kidney failure and mortality. Of 2421 available biopsies, 2103 individuals were linked to administrative data, of which 1292 had a common glomerular disease. The incidence of yearly biopsies increased almost 3-fold over the study period. Among common glomerular diseases, immunoglobulin A (IgA) nephropathy was the most common (28.6%), whereas infection-related GN had the highest proportions of kidney failure (70.3%) and all-cause mortality (42.3%). Predictors of kidney failure included urine albumin-to-creatinine ratio at the time of biopsy (adjusted hazard ratio [HR] = 1.43, 95% confidence interval [CI] = 1.24-1.65), whereas predictors of mortality included age at the time of biopsy (adjusted HR = 1.05, 95% CI = 1.04-1.06) and infection-related GN (adjusted HR = 1.85, 95% CI = 1.14-2.99, compared with the reference category of IgA nephropathy). Retrospective, single-center study with a relatively small number of biopsies. Creation of a comprehensive glomerular diseases registry is feasible and can be facilitated through the use of novel data extraction methods. This registry will facilitate further epidemiological research in GN.

Measurement of Complement Activation via Plasma-Soluble C5b-9 Comparison with Terminal Complement Complex Staining in a Series of Kidney Biopsies

Introduction: With the emergence of therapeutic complement inhibitors, there is a need to identify patients with complement-driven inflammation. C5b-9 is the terminal product of the three complement pathways and therefore a marker of total complement activation. We present a pilot study which aims to assess whether plasma soluble C5b-9 (sC5b-9) correlates with terminal complement complex (TCC) staining in kidney tissue. The secondary aim was to assess the utility of plasma sC5b-9 as part of routine workup in kidney patients undergoing kidney biopsy. Methods: Thirty-seven patients undergoing kidney biopsy had plasma sC5b-9 and TCC staining on kidney tissue performed. Additional blood markers including creatinine, haemoglobin, CRP, factor H, factor I, and midkine levels were also taken. These parameters were correlated with the histological diagnoses. Patients were divided into a diseased group (n = 31) and a control group (n = 6) consisting of transplanted kidneys with minor or no changes. Of the biopsies in the control group, 50% were performed as per protocol, and the other 50% were performed due to clinical need. Results: There was no correlation found between plasma sC5b-9 and TCC kidney staining. Elevated sC5b-9 levels were found in a heterogeneous group of patients but were associated with higher CRP and lower haemoglobin levels. Overall, there was more TCC kidney staining in the diseased group compared with the control group, and a trend was observed of diabetic, primary membranous nephropathy, and amyloidosis patients having more intense glomerular and peritubular/interstitial staining. Conclusion: Plasma sC5b-9 as a marker of total complement activation does not correlate with TCC kidney staining. This discordance suggests that plasma sC5b-9 and TCC staining are distinct markers of disease. TCC staining reflects chronicity and tissue deposition of complement over time. Conversely, plasma sC5b-9 concentrations change rapidly and reflect systemic complement activation. Complement activation was present in a heterogeneous group of kidney disease, indicating the underlying role of complement in many disorders.

An 8-month-old boy with infantile nephrotic syndrome caused by semaphorin 3B-associated membranous nephropathy.

We present a case of nephrotic syndrome caused by semaphorin 3B-associated membranous nephropathy. The patient was an 8-month-old male infant who presented with severe proteinuria and hypertension. He was treated with prednisolone (PSL) for nephrotic syndrome; however, remission was not achieved within 4weeks. He was diagnosed with steroid-resistant nephrotic syndrome and underwent kidney biopsy. Pathological examination revealed membranous nephropathy with IgG deposits on both the glomerular basement membrane (GBM) and the tubular basement membrane (TBM). He was treated with cyclosporine (CsA) in addition to PSL and achieved complete remission. However, frequent relapses occurred after the discontinuation or tapering of immunosuppressants. Two years after treatment initiation, a second biopsy was performed and showed worsening of the disease, which required treatment with several immunosuppressants to achieve complete remission. After that, we performed additional immunostaining for semaphorin 3B, which confirmed the diagnosis of semaphorin 3B-associated membranous nephropathy. Although extremely rare in infantile cases, semaphorin 3B-associated membranous nephropathy should be considered in the differential diagnosis, as strong treatment with immunosuppressants might be needed. In addition, mycophenolate mofetil showed an effective clinical response in this case, indicating that it can be considered for future treatment strategies.

The spectrum and changes of biopsy-proven kidney diseases in Chinese children.

The study aimed to investigate the spectrum of biopsy-proven kidney disease in Chinese children. Records of children 0-17years old who underwent native kidney biopsy from June 1st, 2013 to December 31st, 2018 in the national inpatients' database of China were analyzed. Biopsy-proven kidney diseases of different sex, age groups, and diagnosis, and the changing patterns of kidney disease compared with the previous study were analyzed. A total of 21,311 patients from 232 hospitals with a median age of 11.34years were included. Immunoglobulin A vasculitis with nephritis (IgAVN) was the most common pathological finding [29.17%, 95% confidence interval (confidence interval, CI) = 28.56-29.78], followed by IgA nephropathy (IgAN) (22.70%, 95% CI = 22.14-23.27). IgAN was the most common finding in patients with hematuria (60.75%, 95% CI = 58.83-62.65], proteinuria (33.43%, 95% CI = 30.54-36.42), and hematuria plus proteinuria (62.77%, 95% CI = 56.19-69.02). Minimal change disease was the most common finding (40.69%, 95% CI = 39.41-41.98) in nephrotic syndrome. The proportion of IgAVN in patients with biopsy-proven glomerular disease increased year by year during 2013-2018 (p for trend < 0.001) and washigher than that of2004-2014 [29.41% (95% CI = 29.10-29.72) in 2013-2018 vs. 13.35% (95% CI = 12.97-13.73) 2004-2014, p < 0.001]. The proportion of hepatitis B virus associated nephritis during 2013-2018 was lower than that of 2004-2014 [0.44% (95% CI = 0.36-0.54) in 2013-2018 vs. 0.87% (95% CI = 0.67-1.10) in 2004-2014, p < 0.001]. IgAVN and IgAN were the most common types of pathological findings in children who underwent kidney biopsies from 2013 to 2018. The pathological spectrum of kidney biopsy changed over time.

Dent Disease Type 1: Still an Under-Recognized Renal Proximal Tubulopathy: A Case Report

Dent disease is a rare renal tubular disorder that appears almost exclusively in males. The diagnosis is still challenging, and therefore Dent disease is occasionally misdiagnosed. We report a case of a 45-year-old man with Dent disease who developed renal failure. Since the age of 7 months, he persistently exhibited proteinuria. At the age of 24 years, he underwent kidney biopsy, which revealed focal segmental glomerulosclerosis. The patient’s brother was found to have proteinuria since he was 2 years old. At the age of 45 years, the patient was transferred to a tertiary care nephrologist, and Dent disease was suspected. Genetic testing revealed a CLCN5 mutation. We highlight the broad spectrum of clinical manifestations in Dent disease and the importance of having a high clinical suspicion to attain a definitive diagnosis. Furthermore, future research regarding the clinical course of the disease, prognosis, and effective treatment options is needed.

Development of an instrument to predict proliferative histological class in lupus nephritis based on clinical and laboratory data.

To compare the correlations of histological class inferences based on clinical manifestations and laboratory tests between rheumatologists and nephrologists, to determine the associations of clinical and laboratory data with histological classes and to develop an instrument that can assist histological class identification in lupus nephritis (LN). Retrospective study based on medical records of 80 systemic lupus erythematosus patients (SLICC criteria classification, 2012) who underwent kidney biopsy between 2010 and 2017. Two rheumatologists and two nephrologists received clinical and laboratory data and answered questions regarding which histological class was expected on kidney biopsy. Kappa (K) coefficient was used to assess agreement between evaluators. A decision tree was constructed using the chi-square interaction detector and logistic regression was performed for the development of the proliferative histological class predictor instrument. The mean age and disease duration were 33 ± 10.3years and 11.5 ± 6.7years, respectively. The level of agreement between the evaluators and kidney biopsy was poor (global K 0.364 ± 0.029; p < .001). Analyzing clinical and laboratory variables as predictors of proliferative histological class, patients with abnormal urinary sediment and positive anti-dsDNA antibodies presented 13.96 and 4.96times higher risks of presenting class III or IV, respectively (p < 0.001). Our instrument has a sensitivity of 87.8% and specificity of 80%, using abnormal urinary sediment, anti-dsDNA antibodies, and serum creatinine as variables. Rheumatologists and nephrologists with experience in treating LN generated evaluations that correlated weakly with kidney biopsy. When kidney biopsy is unavailable or is contraindicated for medical reasons, instruments based on clinical and laboratory predictors may be helpful.

Diagnostic accuracy of ultrasound-based multimodal radiomics modeling for fibrosis detection in chronic kidney disease

ObjectivesTo predict kidney fibrosis in patients with chronic kidney disease using radiomics of two-dimensional ultrasound (B-mode) and Sound Touch Elastography (STE) images in combination with clinical features.MethodsThe Mindray Resona 7 ultrasonic diagnostic apparatus with SC5-1U convex array probe (bandwidth frequency of 1–5 MHz) was used to perform two-dimensional ultrasound and STE software. The severity of cortical tubulointerstitial fibrosis was divided into three grades: mild interstitial fibrosis and tubular atrophy (IFTA), fibrotic area < 25%; moderate IFTA, fibrotic area 26–50%; and severe IFTA, fibrotic area > 50%. After extracting radiomics from B-mode and STE images in these patients, we analyzed two classification schemes: mild versus moderate-to-severe IFTA, and mild-to-moderate versus severe IFTA. A nomogram was constructed based on multiple logistic regression analyses, combining clinical and radiomics. The performance of the nomogram for differentiation was evaluated using receiver operating characteristic (ROC), calibration, and decision curves.ResultsA total of 150 patients undergoing kidney biopsy were enrolled (mild IFTA: n = 74; moderate IFTA: n = 33; severe IFTA: n = 43) and randomized into training (n = 105) and validation cohorts (n = 45). To differentiate between mild and moderate-to-severe IFTA, a nomogram incorporating STE radiomics, albumin, and estimated glomerular filtration (eGFR) rate achieved an area under the ROC curve (AUC) of 0.91 (95% confidence interval [CI]: 0.85–0.97) and 0.85 (95% CI: 0.77–0.98) in the training and validation cohorts, respectively. Between mild-to-moderate and severe IFTA, the nomogram incorporating B-mode and STE radiomics features, age, and eGFR achieved an AUC of 0.93 (95% CI: 0.89–0.98) and 0.83 (95% CI: 0.70–0.95) in the training and validation cohorts, respectively. Finally, we performed a decision curve analysis and found that the nomogram using both radiomics and clinical features exhibited better predictability than any other model (DeLong test, p < 0.05 for the training and validation cohorts).ConclusionA nomogram based on two-dimensional ultrasound and STE radiomics and clinical features served as a non-invasive tool capable of differentiating kidney fibrosis of different severities.Key Points• Radiomics calculated based on the ultrasound imaging may be used to predict the severities of kidney fibrosis.• Radiomics may be used to identify clinical features associated with the progression of tubulointerstitial fibrosis in patients with CKD.• Non-invasive ultrasound imaging-based radiomics method with accuracy aids in detecting renal fibrosis with different IFTA severities.

Direct costs associated with lupus nephritis management in the Private Healthcare System in Brazil: an expert panel perspective

Objective: To estimate direct medical costs of lupus nephritis (LN) in the Brazilian private healthcare system. Methods: An expert panel of five specialists were convened to discuss health resource usage in LN patient management. The discussion included diagnosis, treatment, and disease monitoring, including dialysis and kidney transplantation. Unit costs (in BRL) were obtained from public sources, and an estimation of 1-year costs was conducted. Results: Approximately 76.0% of patients with LN undergo kidney biopsy, of which 48.1% present with LN classes III–IV and 21.4% have class V. Around 67.5% of patients with LN classes III–IV experience an average of four renal flares annually. Overall, 20.3% of patients present refractory LN, and 10.3% have end-stage kidney disease (ESKD), requiring dialysis and kidney transplantation. Estimated total weighted annual costs per patient were BRL 115,824.81 for LN classes III–IV, BRL 85,684.79 for LN class V, BRL 115,594.98 for refractory LN; and BRL 325,712.88 for ESKD. The main annual cost driver for LN classes III–IV was renal flares (BRL 60,240.41; 52.0%) and dialysis for LN class V (BRL 31,128.38; 36.3%). Conclusions: Total direct costs increase when LN progresses to ESKD. Although it is challenging to improve the diagnosis, identification of the disease at an early stage, together with rapid initiation of treatment, are fundamental elements to optimize results, potentially reducing costs to the system and the impact of disease burden and quality of life on patients.

Baseline Proteinuria and Serum Creatinine Concentration as Clinical Predictors of Complete Renal Response in Patients with Lupus Nephritis: A Single-Center Experience.

The aim of the study was to identify robust predictors of complete renal response (CRR), within 36 months, in a single-center cohort of lupus nephritis (LN) patients. Patients with biopsy-confirmed LN who underwent kidney biopsy between 1 January 2010 and 31 December 2020 were included and followed up for at least 6 months. CRR was defined as a reduction of urinary protein-to-creatinine ratio (UPCR) below 0.50 g/g. We evaluated baseline demographic, laboratory, and biopsy characteristics as potential predictors of CRR, and selected the variables further evaluated with Kaplan−Meier curves and log-rank tests. The traits with a p-value < 0.1 were later tested with both uni- and multivariable Cox proportional hazard models. Our sample consisted of 57 patients (84% females, median age 32 years), out of which 63.2% reached CRR within 36 months. The initial UPCR and estimated glomerular filtration rate (eGFR) were the only variables in multivariable Cox regression model, which were selected through backward elimination, with a significance threshold <0.05 (HR = 0.77, p = 0.01 and HR = 1.02, p = 0.001). Our results confirmed the role of initial UPCR and serum creatinine concentration (sCr) as predictors of CRR in LN.

The effect of non-albumin proteinuria on renal outcomes in patients with biopsy proven diabetic nephropathy.

We aimed at investigating the effect of non-albumin proteinuria on renal outcomes in patients with biopsy-proven diabetic nephropathy. The files of all patients who underwent kidney biopsy between January 2010 and January 2020 were reviewed retrospectively. Non-albumin proteinuria was calculated by subtracting albumin from total protein in 24-hour urine samples. The patients were divided into 2 groups, according to the presence of composite kidney outcomes. The study included 23 patients with diabetic nephropathy. The kidney endpoint was achieved in 34.8% (n=8) of the patients. Hypertension, duration of diabetes mellitus, creatinine level at the date of biopsy, microalbuminuria and non-albumin proteinuria were found to be independent predictors for composite kidney outcome (p=0.002, p=0.007, p=0.004, p=0.006, and p=0.001, respectively). NAP was found to be an independent risk factor for doubling the serum creatinine level from the date of biopsy, for starting hemodialysis or peritoneal dialysis, for kidney transplantation, and kidney-related death.

PSAT181 Amyloidosis as a Possible Cause of Hypoparathyroidism

Abstract Background Hypoparathyroidism is a relatively uncommon metabolic disorder with an estimated prevalence of 37 per 100,000 person-years in the United States. Postsurgical hypoparathyroidism is the most common etiology and accounts for 75% of the cases. Nonsurgical cases are frequently the result of autoimmune or genetic disorders. Rarely parathyroid gland infiltration, external radiation treatment is also known cause hypoparathyroidism. We present a rare case of hypoparathyroidism associated with amyloidosis. Case 61-year-old female presented for evaluation of hypothyroidism and hypoparathyroidism and significant fatigue. Patient was already treated with levothyroxine as well as calcitriol at the time of presentation for management of these issues without improvement in her fatigue. Further review of prior records showed progressive decline in kidney function and albumin, hypothyroidism in addition to worsening hypocalcemia evidenced on ionized calcium levels over a two year period. This also coincided with the duration of the onset of fatigue. Past medical history was also significant for parathyroid surgery for primary hyperparathyroidism 12 years prior to the onset of symptoms. Patient did not develop hypoparathyroidism after surgery but maintained normal calcium levels until onset of symptoms 2 years ago.Physical exam did not reveal any abnormalities. Labs (when patient was receiving calcitriol) revealed a calcium of 9.5mg/dL (8.4-10.2mg/dL), with albumin 2.3g/dL(3.8-5.3g/dL), ionized calcium 1.27mmol/L(1.14-1.33mmol/L), 25-hydroxy Vitamin D 14ng/mL(&amp;gt;/=30ng/mL), PTH 7pg/mL(15-88pg/mL), Phosphorus 3.4mg/dL(2.4-4.8 mg/dL), Magnesium 2.6mg/dL(1.8-3.0 mg/dL), Creatinine 2.45mg/dL(0.40-0.99 mg/dL), eGFR 21 mL/min/1.73m2. She was trialled off calcitriol to assess for improvement of her PTH, however was noted to have inappropriately normal PTH despite hypocalcemia and was restarted on calcitriol. TPO antibody and 21 hydroxylase antibody levels were not elevated. Due to CKD, She underwent kidney biopsy that revealed lambda light chain amyloidosis. Patient is currently receiving daratumumab and Cyclophosphamide-Bortezomib-Dexamethasone and plans to undergo stem cell transplant in future. Conclusion Notably, the occurrence of amyloidosis with hypothyroidism and infiltrative amyloid goiter is well documented. Although prior case studies have detailed the co-occurrence of hyperparathyroidism and amyloidosis, little is known about the relationship of parathyroid disease and amyloidosis. Due to the temporal association of amyloidosis, hypoparathyroidism, and hypothyroidism, we hypothesize that infiltration of these endocrine glands by amyloid has contributed to the dysfunction. The patient will be monitored for improvement in her parathyroid function as the amyloidosis is treated. Further studies are needed to assess the interplay between the parathyroid and amyloidosis. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

Transdermal Estrogen Provides Comparable Effectiveness With Desmopressin in Preventing Uremic Bleeding in CKD Patients Undergoing Kidney Biopsy: A Pilot Randomized, Double-Blinded Controlled Trial

Transdermal Estrogen Provides Comparable Effectiveness With Desmopressin in Preventing Uremic Bleeding in CKD Patients Undergoing Kidney Biopsy: A Pilot Randomized, Double-Blinded Controlled Trial

Clinical and histopathological study of renal biopsy in Nepalese children: A single center experience.

BackgroundGlomerular diseases are important causes of morbidity and mortality among children in developing countries. Renal biopsy is the gold standard for determining histological diagnosis, prognosis, and therapy options. This study aimed to investigate the clinical, histopathological, and direct immunofluorescence findings of renal biopsy results in Nepalese children under 18 years old.MethodsIn this retrospective cross-sectional study, the available data from children who had undergone kidney biopsy between 2016 and the end of 2020 were evaluated. Demographic data, indications of biopsy, histopathologic findings, and direct immunofluorescence findings were collected and presented.ResultsThe mean age of the patients was 12.14 ± 4.07 years. Male/female ratio was 1:1. The majority of biopsy cases were aged between 11–15 years of age. The most common indication for biopsy in children was nephrotic syndrome (68.25%). Lupus nephritis with 28 cases (22.22%) had the highest frequency in overall renal biopsies. Minimal change disease (MCD) with 22 cases (17.46%) followed by Ig A nephropathy with 16 cases (12.69%) were the most frequent primary glomerulonephritis. Lupus nephritis showed full house positivity, and MCD showed full house negativity in all Direct immunofluorescence (DIF) parameters, whereas immunoglobulin A nephropathy showed 100% positivity in Ig A in DIF.ConclusionsNephrotic syndrome was the most common indication for renal biopsy. The most common primary glomerulonephritis was MCD, while secondary glomerulonephritis was lupus nephritis. Clinical data, light microscopy, and direct DIF played an integral role in the overall final diagnosis.

Immune checkpoints inhibitors and its link to acute kidney injury and renal prognosis.

Immunotherapy with immune checkpoint inhibitors (ICPi) may cause acute kidney injury (AKI) and their use is increasing. This is a single-center retrospective cohort study of patients receiving ICPi drugs for solid organ malignancies. ICPi-related AKI, the need for renal replacement therapy during or following ICPi treatment, and the associated mortality was studied. Two hundred thirty five patients were included in the final analysis. Patients with (N = 40) and without (n = 195) AKI had similar age, sex, type of ICPi, baseline serum creatinine levels, comorbidities and mortality; while patients with AKI were more likely to be receiving a nephrotoxic agent or be treated for genitourinary malignancy. 18 patients had ICPi-related AKI; 7 of these patients underwent kidney biopsy, which showed acute interstitial nephritis while the remaining 11 were diagnosed on clinical parameters. 18 (45%) patients recovered kidney function after AKI. No differences were observed between patients with and without kidney function recovery, although patients without recovery had a numerical, but not statistically significant, higher mortality. Patients with biopsy-confirmed ICPi-induced AKI had an increased risk of mortality, as compared with the rest of the population-HR 1.83, 95% CI 1.22-2.74, p = 0.003. Use of nephrotoxic drugs and the location of malignancy appear to be common drivers of AKI in patients receiving ICPis for solid organ malignancy. Whether nephrotoxic agents or urinary tract obstruction may favor ICPi-related autoimmunity should be further studied.

S1826 Severe Steatorrhea in the Setting of Chronic Pancreatitis Leading to Hyperoxaluria and Subsequent Oxalate Nephropathy Necessitating Dialysis

Introduction: Steatorrhea is a common clinical entity encountered by gastroenterologists spanning a wide array of patient populations. In addition to causing disruptive symptoms which negative impact quality of life, steatorrhea leads to fat-soluble vitamin deficiency and the corresponding adverse affects including mineral and bone disease, clotting factor deficiency, and delayed wound healing. While multiple disorders can lead to steatorrhea, this report will focus on chronic pancreatitis. Regardless of the etiology, some patients may ultimately develop hyperoxaluria due to the interaction between non absorbed fat in the gut lumen, calcium, and oxalate. This has the potential to lead to oxalate nephropathy, and in extreme cases, acute renal failure. We herein present the case of an 89-year-old man receiving treatment for chronic pancreatitis who developed acute renal failure requiring dialysis secondary to oxalate nephropathy. Case Description/Methods: Our case involves an 89-year-old man with a past medical history significant for chronic pancreatitis on enzymes replacement, IPMN, and COPD who presented to the hospital at the request of his primary physician for abnormal blood work. On initial evaluation, he was found to be in acute renal failure with a BUN of 104 and creatinine 9.34. Gastroenterology and nephrology teams were consulted. During the course of his stay, our patient was started on dialysis and subsequently underwent kidney biopsy, which revealed oxalate nephropathy. He did not undergo invasive testing such as EGD with secretin administration and subsequent duodenal bicarbonate aspiration to confirm pancreatic insufficiency, as this diagnosis was assumed from prior gastroenterology evaluation and appropriate clinical findings. He was discharged home after kidney function was stabilized and continues on dialysis at this time. Discussion: This case presentation highlights a potential adverse outcome associated with severe steatorrhea in the setting of chronic pancreatitis, and is a useful lesson for the gastroenterologist so that similar events might be detected at an early stage in future patients. Recognizing acute kidney injury in this setting is of the utmost importance, so that progression to ESRD requiring dialysis may be avoided. Management of steatorrhea in this setting may require aggressive pancreatic enzyme replacement and dietary therapy. Fecal fat quantity may be monitored with stool sudan stain as well as fecal elastase, in an effort to avoid invasive testing.

PULMONARY LIMITED SERONEGATIVE GRANULOMATOSIS WITH POLYANGIITIS VASCULITIS

PULMONARY LIMITED SERONEGATIVE GRANULOMATOSIS WITH POLYANGIITIS VASCULITIS

Renal Prognosis of COVID-19 Associated Nephropathy

COVID-19 associated nephropathy (COVAN) is the most common cause of acute kidney injury (AKI) in Black patients with SARS-CoV-2 infection undergoing kidney biopsy. It presents with AKI and proteinuria, often nephrotic-range. The histopathology of COVAN is collapsing glomerulopathy (CG), the most severe form of focal segmental glomerulosclerosis.1 The pattern of injury of CG is also seen in the setting of other infections (including human immunodeficiency virus, human T-cell lymphotrophic virus-1, filariasis, leishmaniasis, parvovirus B19, cytomegalovirus, and loa loa), autoimmune disease, ischemia, anabolic steroids, and therapeutic or recreational drugs.