Immunofluorescence on paraffin embedded renal biopsies:Experience of a tertiary care center with review of literature

AIMTo describe the technique of immunofluorescence on paraffin embedded tissue sections and discuss the po-tential pitfalls with an in depth review of literature.METHODSImmunofluorescence is integral to diagnostic renal pa-thology. Immunofluorescence on paraffin embedded renal biopsies （IF-P） after enzyme treatment has been described in literature, however has not found widespread use in renal pathology laboratories. In our laboratory proteinase K digestion of paraffn embedded renal biopsy material was standardized and applied prospectively in cases where immunofuorescence on fresh frozen tissue was non contributory or not possible. Diagnostic utility was assessed and in a cohort of cases comparison of intensity of staining with routine immunofuorescence was performed.RESULTSOver the 5-year study period, of the 3141 renal biopsies received IF-P was performed on 246 cases （7.7%） and was interpretable with optimal digestion in 214 cases （6.8%）. It was of diagnostic utility in the majority of cases, which predominantly included glomerular disease. Non-diagnostic IF-P was found in membranous nephropathy （2 of 11 cases）, membranoproliferative glomerulonephritis （2 of 32 cases）, lupus nephritis （1 of 25 cases）, post infectious glomerulonephritis （1 of 11 cases） and chronic glomerulonephritis （3 of 8 cases）. Comparing cases with both routine IF and IF-P, 35 of 37 showed either equal intensity or a minor difference in intensity of staining（1＋） for the diagnostic immunoglobulin/complement. Technically assessment of immunofluorescence on the paraffin embedded tissue was found to be easier with clearly observed morphology, however a false positive staining pattern was observed in under-digested tissue. CONCLUSIONAs a “salvage” technique, immunofuorescence on paraffn embedded renal biopsies is of great diagnostic utility, however not without pitfalls.

Changes in macrophage infiltration and podocyte injury in lupus nephritis patients with repeated renal biopsy: Report of three cases

BACKGROUND In this study,we retrospectively analysed macrophage infiltration and podocyte injury in three patients with diffuse proliferative lupus nephritis(LN)who un-derwent repeated renal biopsy.CASE SUMMARY Clinical data of three diffuse proliferative LN patients with different pathological characteristics(case 1 was LN IV-G(A),case 2 was LN IV-G(A)+V,and case 3 was LN IV-G(A)+thrombotic microangiopathy)were reviewed.All patients underwent repeated renal biopsies 6 mo later,and renal biopsy specimens were studied.Macrophage infiltration was assessed by CD68 expression detected by immunohistochemical staining,and an immunofluorescence assay was used to detect podocin expression to assess podocyte damage.After treatment,Case 1 changed to LN III-(A),Case 2 remained as type V LN lesions,and Case 3,which changed to LN IV-S(A),had the worst prognosis.We observed reduced macro-phage infiltration after therapy.However,two of the patients with active lesions after treatment still showed macrophage infiltration in the renal interstitium.Before treatment,the three patients showed discontinuous expression of podocin.Notably,the integrity of podocin was restored after treatment in Case 1.CONCLUSION It may be possible to reverse podocyte damage and decrease the infiltrating ma-crophages in LN patients through effective treatment.

Risk evaluation for diabetic retinopathy in Chinese renalbiopsied type 2 diabetes mellitus patients

AIM:To investigate diabetic retinopathy(DR)prevalence in Chinese renal-biopsied type 2 diabetes mellitus(T2DM)patients with kidney dysfunction,and to further evaluate its relationship with diabetic nephropathy(DN)incidence and the risk factors for DR development in this population.METHODS:A total of 84 renal-biopsied T2DM patients were included.Fundus and imaging examinations were employed for DR diagnosis.Demographic information and clinical measures along with renal histopathology were analyzed for comparisons between the DR and non-DR groups.Risk factors on DR development were analyzed with multiple logistic regression.RESULTS:DR prevalence was 50%in total.The incidences of DN,non-diabetic renal disease(NDRD)and mixed-type pathology were 47.6%,19.0%and 33.3%in the DR group respectively,while 11.9%,83.3%and 4.8%in the non-DR group.Systolic blood pressure,ratio of urinary albumin to creatine ratio,urinary albumin,24-hours urinary protein,the incidence and severity of DN histopathology were found statistically increased in the DR group.Multiple logistic regression analysis showed histopathological DN incidence significantly increased the risk of DR development[odds ratio(OR)=21.664,95%confidential interval(CI)5.588 to 83.991,P<0.001 for DN,and OR=45.475,95%CI 6.949 to 297.611,P<0.001 for mixed-type,respectively,in reference to (NDRD)],wherein DN severity positively correlated.CONCLUSION:Renal histopathological evidence indicates DN incidence and severity increases the risk of DR development in Chinese T2DM patients inexperienced of regular fundus examinations.

Indications for Renal Needle Biopsy and Histological Spectrum of Kidney Disease in Togo

Introduction: The frequent late-stage diagnosis of chronic kidney disease (CKD) constrains the treatment choices for nephrologists. Renal biopsy (RB) is crucial for accurately identifying renal lesions. This key nephrological procedure, however, is invasive and not without potential complications. The purpose of this study was to evaluate the indications, frequency, and histological lesion profiles of renal biopsies in Togo. Materials and Methods: We conducted a descriptive cross-sectional study encompassing all renal biopsies performed in Togo from the inception of nephrology services to the present. Data were compiled from the medical records of the patients. Results: From 2015 to 2023, 68 high-quality renal biopsies were executed in Togo. The patients had an average age of 30.6 years, with a predominance of males (69.1%). The most common indication was nephrotic syndrome, accounting for 66.2% of cases. Histologically, glomerulopathies were predominant, representing 61.8% of lesions, followed by vascular nephropathies (25%) and tubulointerstitial nephropathies (13.2%). The most frequently observed primary glomerulopathy was focal segmental glomerulosclerosis (FSGS). Gross hematuria was the sole complication, occurring in 1.4% of the cases. Conclusion: RB is an evolving practice in Togo. Glomerulopathies are the most commonly observed lesions. The histological categorization of renal lesions is vital for clinicians in their diagnostic reasoning and approach.

Post-Renal Biopsy Deglobulization: Risk Factors and Prognosis: A Study of 157 Biopsies

Introduction: Percutaneous renal biopsy (PRB) is the gold standard for the diagnosis of most renal diseases. It is a safe and effective modality for the collection of renal tissue. However, many safety measures are not based on sufficient evidence and therefore vary considerably from a center to another. The aim of this work is to determine the rate of bleeding complications, to identify the risk factors for these complications, and to clarify the post renal biopsy prognosis. Materials and Methods: We performed a single-center retrospective observational study in the nephrology department at the University Hospital of Fez, including all patients who underwent percutaneous renal biopsy on native kidney between January 2018 and December 2019. Results: Overall, 157 biopsies were performed. Deglobulization was present in 20.4% (40) of patients, the mean age of patients was 41.57 ± 16.11 years [16.78]. The sex ratio M/F: 1.22. Diabetes mellitus was present in four cases (11.1%), arterial hypertension was present in four cases (11.1%). On clinical examination, systolic hypertension was found in 45.7%, diastolic hypertension in 45%, antihypertensive therapy was initiated in all patients with hypertension before. Hyperuremia was present in 29 patients (80.6%), renal failure was present in 77.8%. Anemia was present in 55.6%, thrombocytopenia in six cases (16.7%). Radiologically, the size of the kidneys was reduced in 5 patients (17.2%), differentiation was limited in 5 patients (17.2%). Major complications occurred in 3.8% (6/157). These six patients had a lumbar pain and required blood transfusions. A radiological embolization procedure was indicated in only one patient. Minor complications were seen in 21.6% (34/157). The diagnoses that were retained in patients with deglobulization were: Lupus in 34.71%, pauci-immune vasculitis in 13.79%, membranous glomerulonephritis in 10.34%, focal and segmental hyalinosis in 10.34%, membrano-proliferative glomerulonephritis in 10.34%. In univariate and multivariate analysis, the major risk factors for deglobulization found in our patients were: hyperuremia 80.6% (p: 0.017), acute renal failure 77.8% (p: 0.04), acute hemodialysis 24.7% (p: 0.02), hyperphosphatemia 63.6% (0.04). Conclusion: Renal biopsies are an overall safe procedure with rare major complications. Post-renal biopsy deglobulization is common. Routine post-biopsy ultrasound may not be necessary. Renal biopsies can be performed safely if risk factors are controlled, such as renal failure, hyperuremia, hyperphosphatemia, hemodialysis patients and a diagnosis of lupus nephropathy.

Exploring kidney biopsy findings in congenital heart diseases:Insights beyond cyanotic nephropathy

BACKGROUND The association between congenital heart disease and chronic kidney disease is well known.Various mechanisms of kidney damage associated with congenital heart disease have been established.The etiology of kidneydisease has commonly been considered to be secondary to focal segmental glomerulosclerosis(FSGS),however,this has only been demonstrated in case reports and not in observational or clinical trials.AIM To identify baseline and clinical characteristics,as well as the findings in kidney biopsies of patients with congenital heart disease in our hospital.METHODS This is a retrospective observational study conducted at the Nephrology Depart-ment of the National Institute of Cardiology“Ignacio Chávez”.All patients over 16 years old who underwent percutaneous kidney biopsy from January 2000 to January 2023 with congenital heart disease were included in the study.RESULTS Ten patients with congenital heart disease and kidney biopsy were found.The average age was 29.00 years±15.87 years with pre-biopsy proteinuria of 6193 mg/24 h±6165 mg/24 h.The most common congenital heart disease was Fallot’s tetralogy with 2 cases(20%)and ventricular septal defect with 2(20%)cases.Among the 10 cases,one case of IgA nephropathy and one case of membranoproliferative glomerulonephritis associated with immune complexes were found,receiving specific treatment after histopathological diagnosis,delaying the initiation of kidney replacement therapy.Among remaining 8 cases(80%),one case of FSGS with perihilar variety was found,while the other 7 cases were non-specific FSGS.CONCLUSION Determining the cause of chronic kidney disease can help in delaying the need for kidney replacement therapy.In 2 out of 10 patients in our study,interventions were performed,and initiation of kidney replacement therapy was delayed.Prospective studies are needed to determine the usefulness of kidney biopsy in patients with congenital heart disease.

Patterns of kidney diseases diagnosed by kidney biopsy and the impact of the COVID-19 pandemic in Yogyakarta,Indonesia:A single-center study

BACKGROUND Glomerular diseases rank third among the causes of chronic kidney disease worldwide and in Indonesia,and its burden continues to increase,especially regarding the sociodemographic index.Kidney biopsy remains the gold standard for the diagnosis and classification of glomerular diseases.It is crucial for developing treatment plans,determining the degree of histologic changes,and identifying disease relapse.AIM To describe the patterns of biopsy-proven kidney diseases in adult patients.METHODS We retrospectively reviewed the demographic,histopathologic,clinical,and laboratory data of 75 adult patients with biopsy-proven kidney diseases at our institution recorded from 2017 to 2022.RESULTS Among the patients,43(57.3%)were females,and the mean age was 31.52 years±11.70 years.The most common histopathologies were lupus nephritis(LN)(33.3%),minimal change disease(MCD)(26.7%),and focal segmental glomerulosclerosis(10.7%).LN(41.7%)was frequently diagnosed in women and MCD(28.1%)in men.The most common cause of nephritic syndrome was LN(36.7%)and of nephrotic syndrome was MCD(40%).CONCLUSION Different kidney disease patterns were observed in different sexes,age categories,clinical syndromes,and biopsy dates relative to the coronavirus disease 2019 pandemic.

Relationship between Renalase Expression and Kidney Disease： an Observational Study in 72 Patients Undergoing Renal Biopsy

The relationship between the levels of renalase and changes in proteinuria, hypertension, renal function, renal tubular epithelial cell apoptosis and B-cell lymphoma-2 （Bcl-2） expression was investigated in patients （chronic nephritis, primary nephrotic syndrome or other kidney disease） that underwent renal biopsy. The study group comprised 72 patients undergoing renal biopsy. Patient profiles and renal function were collected. Concentrations of renalase and Bcl-2 were measured by immunohistochemistry. Tubular injury was detected by periodic acid Schiff staining （PAS） and renal tubular epithelial cell apoptosis was assessed by TUNEL assay. The expression of renalase was significantly lower in renal biopsy specimens than in normal kidney tissues. There was a positive linear relationship between renalase and some serum and cardiac indices; a negative correlation was found between age, eGFR, Ccr and 24-h urinary protein. Renal tubule injury index and tubular epithelial cell apoptosis index showed a negative linear correlation with renalase. The results showed that renalase probably increased the expression of Bel-2. By two independent samples t-test, renalase levels were significantly increased in the non-hypertension group than in the hypertension group. One-way ANOVA showed that renalase expression was higher in samples with Lee＇s grade Ⅲ than in those with Lee＇s grade V. The expression of renalase was significantly decreased in patients who underwent renal biopsy, and was also associated with blood and renal function. The research proved that renalase may reduce renal tubular injury and apoptosis of renal tubular epithelial cells through the mitochondrial apoptosis pathway, finally achieving the purpose of delaying the progress of renal failure.

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 hae-maturia or asymptomatic hematoma to life-threatening hemorrhage. Several risk factors for complications after RB have been identifed, including high blood pressure, age, decreased renal function, obesity, anemia, low platelet count and hemostasis disorders. These should be carefully assessed and, whenever possible, correct-ed before the procedure. The incidence of serious com-plications has become low with the use of automated biopsy devices and ultrasound guidance, which is cur-rently the “gold standard” procedure for percutaneous RB. An outpatient biopsy may be considered in a care-fully selected population with no risk factor for bleed-ing. 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 bi-opsy in patients at high risk of bleeding, although some factors limit their use. This aim of this review is to sum-marize the issues of complications after RB, assessment of hemorrhagic risk factors, optimal biopsy procedure and strategies aimed to minimize the risk of bleeding.

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 benefts 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.

Goodpasture syndrome and hemorrhage after renal biopsy: A case report

BACKGROUND Goodpasture syndrome(GS) is a rare disease, the morbidity of which is estimated to be 0.5-0.8 per million per year. Hemorrhage is the most serious complication in renal biopsy. Despite the fact that both GS and hemorrhage after renal biopsy are rare, it has not been reported that they are likely to occur in the same patient.CASE SUMMARY A 30-year-old man with diffuse pulmonary hemorrhage and rapid progressive renal function caused by anti-glomerular basement membrane disease presented atypical symptoms without hemoptysis, accompanied by life-threatening hypoxemia. Plasmapheresis was performed, and glucocorticoids and cyclophosphamide were administered. The patient started to show signs of improvement. Percutaneous renal biopsy is an appropriate diagnostic measure that is commonly safe, but this patient experienced hemorrhage after operation,thus necessitating embolization of the renal artery to stop the bleeding. The patient’s condition was improved, and the serum anti-glomerular basement membrane antibody level was 106 AU/m L(normal range: < 24 AU/m L) and slowly decreased. His discharge medications were oral daily prednisone(30 mg)and continued maintenance hemodialysis.CONCLUSION GS is a rare organ-specific autoimmune disease that is invariably ubiquitous in the lung and kidney areas. Renal biopsy is the appropriate procedure for the treatment of GS disease, although it is an invasive measure.

Heterogeneity and renal mass biopsy:a review of its role and reliability

Increased abdominal imaging has led to an increase in the detection of the incidental small renal mass(SRM). With increasing recognition that the malignant potential of SRMs is heterogeneous, ranging from benign(15%-20%) to aggressive(20%), enthusiasm for more conservative management strategies in the elderly and infirmed, such as active surveillance(AS), have grown considerably. As the management of the SRM evolves to incorporate ablative techniques and AS for low risk disease, the role of renal mass biopsy(RMB) to help guide individualized therapy is evolving. Historically, the role of RMB was limited to the evaluation of suspected metastatic disease, renal abscess, or lymphoma. However, in the contemporary era, the role of biopsy has grown, most notably to identify patients who harbor benign lesions and for whom treatment, particularly the elderly or frail, may be avoided. When performing a RMB to guide initial clinical decision making for small, localized tumors, the most relevant questions are often relegated to proof of malignancy and documentation(if possible) of grade. However, significant intratumoral heterogeneity has been identified in clear cell renal cell carcinoma(ccRCC) that may lead to an underestimation of the genetic complexity of a tumor when single-biopsy procedures are used. Heterogeneous genomic landscapes and branched parallel evolution of ccRCCs with spatially separated subclones creates an illusion of clonal dominance when assessed by single biopsies and raises important questions regarding how tumors can be optimally sampled and whether future evolutionary tumor branches might be predictable and ultimately targetable. This work raises profound questions concerning the genetic landscape of cancer and how tumor heterogeneity may affect, and possibly confound, targeted diagnostic and therapeutic interventions. In this review, we discuss the current role of RMB, the implications of tumor heterogeneity on diagnostic accuracy, and highlight promising future directions.

Effect of Bundle Care on Deep Venous Thrombosis in Patients Received Renal Biopsy

Objective: To explore the effect of bundle care on the incidence of venous thromboembolism (VTE) in patients who received renal biopsy, and provide reference for clinical care. Methods: 300 patients with nephrotic syndrome who received renal biopsy in our hospital from February 2018 to August 2020 were selected and randomly divided into the observation group and the control group, with 150 patients in each group. In the control group, patients were given routine care: informing the precautions before and after operation, observing the changes of vital signs and bleeding after operation, etc. In the observation group, patients were given bundle care intervention, including preoperative, intraoperative and postoperative routine care, ankle pump exercise, Intermittent Pneumatic Compression (IPC) treatment and psychological care. The incidence of lower-limb venous thrombosis was compared between the two groups. Results: The incidence of deep venous thrombosis in the observation group was lower than that in the control group (P < 0.05), 1 case (0.6%) in the observation group and 8 cases (5.3%) in the control group;the peak velocity and mean velocity of lower-limb venous blood flow in the observation group were higher than those in the control group;the average length of stay in the observation group was less than that in the control group, and the satisfaction degree in the observation group was higher than that in the control group. The differences were statistically significant (P < 0.05). Conclusion: For patients who received renal biopsy, bundle care can help improve the peak velocity and mean velocity of venous blood flow, reduce the incidence of VTE, the average length of stay, and social costs, relieve their pain, and improve satisfaction degree of care;moreover, it plays an important role in reducing the incidence of deep venous thrombosis.

Study on the Effect of Canceling Hard Bed on Patients after Renal Needle Biopsy

Objective: To investigate the effect of hard bed on postoperative complications and comfort level of patients after renal puncture biopsy. Methods: A total of 115 patients who underwent renal needle biopsy in the Department of Nephrology of The First Affiliated Hospital of Jinan University from May 2020 to February 2021 were selected, and 57 patients who received hard bed nursing after renal needle biopsy were set as the control group, the others were selected as the observation group. The incidence of postoperative bleeding at the puncture mouth, gross hematuria and dysuria, as well as the postoperative comfort level of 6 h and 18 h were compared between the two groups. Results: There was no significant difference in the incidence of postoperative bleeding, gross hematuria and dysuria between the two groups (P > 0.05), but the comfort scores at 6 h and 18 h in the observation group were higher than those in the control group (P < 0.05). Conclusion: There is no significant difference in the incidence of postoperative complications, such as bleeding at the puncture mouth, gross hematuria and dysuria, among patients with renal needle biopsy, whether to use hard bed nursing or not. Eliminate hard bed nursing can improve the comfort level of patients, reduce the occurrence of pressure ulcers, and relieve the negative psychological emotions of patients.

Renal biopsy reports in nephritic syndrome:Update

BACKGROUND Nephritic syndrome(NiS)is a major indicator of serious renal diseases necessitating kidney biopsies for histopathological evaluations,but due to the lack of comprehensive reviews in the literature,the current understanding of the syndrome and its significance is limited.AIM To collect all the evidence retrievable from the literature on the diagnoses made on the renal biopsies performed for NiS as the indication to the procedure.METHODS A literature search was conducted to find studies reporting final diagnoses on renal biopsies in NiS patients.Data were pooled and analyzed with stratifications on age and regions.Meta-analyzes were performed using Stata v.9.RESULTS Overall,26414 NiS patients from the total number of 96738 kidney biopsy diagnoses reported by 47 studies from 23 countries from all continents(except sub-Saharan Africa)were found and analyzed.NiS was the indication for renal biopsy in 21%of the patient populations across the reviewed studies.Immunoglobulin A(IgA)nephropathy was the single most frequent diagnosis in these patients(approximately 38%)followed by lupus nephritis(approximately 8%)and Henoch Schönlein purpura(approximately 7%).IgA nephropathy was the most frequent diagnosis reported for the NiS patients from the East Asia,comprising half of all the cases,and least prevalent in South Asia.Considering the age subgroups,adult(vs pediatric or elderly)patients were by far the most likely age group to be diagnosed with the IgA nephropathy.A myriad of such regional and age disparities have been found and reported.CONCLUSION As the indication for renal biopsy,NiS represents a very distinctive epidemiology of final renal disease diagnoses compared to the other major syndromes.

Membranous nephropathy with systemic light-chain amyloidosis of remission after rituximab therapy:A case report

BACKGROUND About 70%-80%of patients with primary membranous nephropathy(MN)have phospholipase A2 receptor(PLA2R)in renal tissue.Systemic light-chain(AL)amyloidosis is the most common type of amyloidosis.MN complicated with amyloidosis is rare.CASE SUMMARY A 48-year-old Chinese male presented with nephrotic syndrome,positive serum PLA2R antibody,and positive serum and urine IgG-lambda type M-protein,with a normal ratio of serum-free light-chain level.The patient was diagnosed with MN accompanied by AL amyloidosis.He was treated with rituximab with glucocorticoids and CyBorD regimen of chemotherapy.After 21 mo of follow-up,the patient achieved complete remission regarding nephrotic syndrome without adverse effects of chemotherapy.CONCLUSION We report a case of PLA2R-related MN complicated with primary AL amyloidosis only with renal involvement and successfully treated with rituximab,glucocorticoids and chemotherapy.

Novel COL4A3 synonymous mutation causes Alport syndrome coexistent with immunoglobulin A nephropathy in a woman:A case report

BACKGROUND Alport syndrome(AS)is an inherited disease of the glomerular basement membrane caused by mutations in genes encodingα3,α4,orα5 chains of type IV collagen.It manifests with hematuria or proteinuria,which is often accompanied by hearing impairments and ocular abnormalities.Histopathologically,AS shows mesangial proliferation and sometimes incidental immunoglobulin A(IgA)deposition.Hematuria or proteinuria is also a common presentation in patients with IgA nephropathy that makes it difficult to differentially diagnose AS and IgA nephropathy solely based on these clinical and pathological features.CASE SUMMARY Herein,we present the case of a 59-year-old female patient who was admitted to our hospital with persistent microscopic hematuria and occasional proteinuria that had lasted for>2 years.This patient had a familial history of renal disease and was diagnosed with autosomal dominant AS(ADAS)and IgA nephropathy based on the findings of renal biopsy as well as genetic testing performed using whole-exome sequencing,which suggested that the patient carried a novel heterozygous variation(c.888G>A:p.Gln296Gln)in the COL4A3 gene that enriches the mutation spectrum of ADAS.The proband received an angiotensin receptor blocker therapy after a definitive diagnosis was established.After one year of therapy,a significant reduction in proteinuria was observed.The number of microscopic red blood cells per high-power field decreased to one-quarter of the baseline levels.Renal function also maintained well during the follow-up.CONCLUSION Our case highlights the significance of performing kidney biopsy and genetic testing in the diagnosis of AS and familial IgA nephropathy.

Clinicopathological Analysis of 155 Patients with Persistent Isolated Hematuria

Objectives To reveal etiologies of persistent isolated hematuria （PIH） through ultrastructural pathological examination, to disclose clinicopathological correlation in cases with PIH, and to summarize appropriate management of patients with PIH. Methods we retrospectively studied 155 P1H patients receiving renal biopsy between January, 2003 and December, 2008 in Peking Union Medical College Hospital. All the clinical data and follow-up result were analyzed. Results All subjects included 38 children and 117 adults, with mean age of 11.38±3.25 years for children and 35.17±8.44 years for adults. Thin basement membrane nephropathy （TBMN） was the most common pathology （55.3% of children and 49.6% of adults）, followed by IgA nephropathy （18.4% of children and 32.5% of adults, mainly grade 2-3） and mesangial proliferative glomerulonephritis （MsPGN） without IgA deposition （13.2% of children and 12.8% of adults）. Besides, A1port syndrome （2.6% of children） and membrane nephropathy （2.6% of children and 0.9% of adults） were demonstrated as other causes of PIH. Elevated mean arteral pressure or protein excretion rate, as well as episodic macrohematuria, indicated higher risk for MsPGN rather than TBMN. On the other hand, severity of microhematuria was irrelevant to pathological types of PIH. Totally, 86 patients were followed up and 37 cases therein stayed on track for long term （mean duration 41.11±28.92 months, range 8-113 months）. Most cases had benign clinical course except 3 cases with TBMN, 5 cases with IgA nephropathy, 1 case with MsPGN （without IgA deposition）, and 1 case with Alport syndrome, who developed hypertension or proteinuria. All of them were administered timely intervention. Conclusions Close follow-up should be required as the primary management for PIH. Equally important is careful monitoring for early identification of undesirable predictors; while renal biopsy and other timely intervention are warranted if there is hypertension, significant proteinuria or renal impairment.

Primary glomerular diseases in the elderly

Primary glomerular diseases in the elderly population are a frustrating topic due to difficulties in both the diagnosis and decision making about treatment. The most frequent type of primary glomerular disease in elderly is membranous nephropathy; while its counterpart in younger population is Ig A nephropathy. The most frequent cause of nephrotic syndrome in the elderly is also membranous nephropathy. Pauci-immune crescentic glomerulonephritis(GN) rate increases both in elderly and very elderly population. Pauci-immune crescentic GNs should be regarded as urgencies in elderly patients as in their younger counterparts due to potential for causing end-stage renal disease in case of delayed diagnosis and treatment, and also causing mortality due to alveolar hemorrhage in patients with pulmonary involvement. Renal biopsy is the inevitable diagnostic method in the elderly as in all other age groups. Renal biopsy prevents unnecessary treatments and provides prognostic data. So advanced age should not be the sole contraindication for renal biopsy. The course of primary glomerular diseases may differ in the elderly population. Acute kidney injury is more frequent in the course and renal functions may be worse at presentation. These patients are more prone to be hypertensive. The decision about adding immune suppressive therapies to conservative methods should be made considering many factors like co-morbidities, drug side effects and potential drug interactions, risk of infection, patient preference, life expectancy and renal functions at the time of diagnosis.

Crumbs homolog 2 mutation in two siblings with steroid-resistant nephrotic syndrome:Two case reports

BACKGROUND Crumbs homolog 2(CRB2)is a recently discovered gene that is closely related to the maintenance of normal polarity in podocytes;mutations can directly lead to steroid-resistant nephrotic syndrome(SRNS).However,the characteristics of nephrotic syndrome(NS)caused by CRB2 mutations have not been described.CASE SUMMARY We report a novel compound heterozygous mutation of the CRB2 gene in two siblings with SRNS.The two siblings had edema,proteinuria,hypoproteinemia and hyperlipidemia.Both their father and mother had normal phenotypes(no history of NS).Whole exon sequencing(WES)of the family showed a novel compound heterozygous mutation,c.2290(exon 8)C>T and c.3613(exon 12)G>A.Glucocorticoid therapy(methylprednisolone pulse therapy or oral prednisone)and immunosuppressive agents(tacrolimus)had no effect.During a 3-year follow-up after genetic diagnosis by WES,proteinuria persisted,but the patient was healthy.CONCLUSION CRB2 mutations related to SRNS often occur in exons 7,10,and 12.Clinical manifestations of SRNS caused by CRB2 mutations are often less severe than in other forms of SRNS.