Sonological predictors of complications of percutaneous renal biopsy-a prospective observational study.

Percutaneous renal biopsy, although essential for renal disease diagnosis, is associated with a number of post-biopsy complications ranging from gross haematuria to AV fistula to death. In this study, we carried out an active haematoma surveillance and attempted to correlate renal sonological parameters-kidney length, renal parenchymal changes, renal cortical and parenchymal thickness for their potential use in prediction of post-renal biopsy complications. METHODS: This was a prospective study done from April 2022 to April 2023 on all adult patients undergoing native or transplant kidney biopsy. Baseline clinical, laboratory and renal sonological parameters were noted prior to biopsy. USG-guided renal biopsy was done and any haematoma at 0 h, 12 h and 24 h post-biopsy noted. Biopsy complications including need for any interventions were noted. RESULTS: Out of the 240 patients enrolled in the study, 58.3% experienced post-biopsy complications. Among these, 5% of patients encountered major complications, with 3.33% necessitating medical intervention following renal biopsy procedures. A high percentage, 98.89%, exhibited hematoma formation within 12 h post-biopsy. Furthermore, our analysis revealed that a hematoma size exceeding 1.2 cm at the 12-h mark exhibited a sensitivity of 100% and specificity of 71% in predicting the need for blood transfusion. Renal parenchymal changes were the most reliable sonological parameters for predicting post-biopsy complication on multivariate analysis. CONCLUSION: The incidence of major complications requiring interventions following renal biopsy is notably low. Our study highlights the significance of renal sonological characteristics, including parenchymal thickness, cortical thickness and parenchymal changes, in predicting these complications. Furthermore, we emphasize the utility of hematoma surveillance immediately post-biopsy and at the 12 h, as a valuable tool for predicting the necessity of post-biopsy interventions. This approach can aid in efficiently triaging patients and determining the need for further observation post-renal biopsy.

Early and late assessment of renal allograft dysfunction using intravoxel incoherent motion (IVIM) and diffusion-weighted imaging (DWI): a prospective study.

PURPOSE: To evaluate the ability of the Intravoxel Incoherent Motion (IVIM) and monoexponentially ADC in renal allograft function in the early and late phases of transplantation, and to predict their effectiveness in discrimination of the graft pathology. METHODS: This is a prospective study included participants scanned with quantitative diffusion and perfusion sequences on a 3-T MR scanner (Philips, Ingenia); the ADC and IVIM parameters; were calculated. Correlations and regression analysis with the eGFR, transplantation periods, and pathology were assessed. RESULTS: This study included 105 renal allograft recipients (85 males, and 20 females with mean age = 32.4 ± 11.9 years and age range = 22-61 years). There was a significant positive correlation between the whole parameters of the ADC and IVIM with eGFR however, the cortical parameters showed higher significant correlation coefficients (p < 0.001). Regression analysis revealed the most significant model can predict eGFR groups included cortical pseudo diffusion (D*) and cortical ADC (p < 0.001). In graft dysfunction eGFR was 61.5 ml/min and normal graft was 64 ml/min. This model demonstrates a high performance of an AUC 96% [0.93-0.97]. In the late transplantation, there is a higher correlation with D* compared to ADC, p-values = 0.001. CONCLUSION: IVIM and ADC Values are significant biomarkers for renal allograft function assessment, cortical ADC, and D* had the highest performance even in situations with mild impairment that is not affect the eGFR yet as cases of proteinuria with normal eGFR. Furthermore, D* is superior to ADC in the late assessment of the renal transplant.

Complicated obstructive uropathy after kidney biopsy: A case report highlighting the risk of biopsy-related acute kidney injury in a patient with unilateral kidney hypoplasia.

Unilateral kidney hypoplasia is a congenital condition characterized by the underdevelopment of one kidney. Although often asymptomatic, it can cause severe renal complications in patients combined with contralateral renal injury, leading to acute renal failure. This case report describes a patient with unilateral kidney hypoplasia who underwent a kidney biopsy on the contralateral normal-sized kidney and subsequently developed oliguric acute kidney injury. This report discusses the challenges encountered while diagnosing and managing this rare case, highlighting the importance of awareness and recognition to perform timely intervention and optimize the patient's outcome.

Reducing Waiting Times and Admission Periods through Pre-Admission Testing: A Quality Improvement Study on In-Hospital Renal Biopsy.

Background: Admission for renal biopsy is considered the gold standard for diagnosing kidney disease. However, prolonged waiting times for admission can lead to delayed diagnosis. Despite this issue, there are currently no studies demonstrating how to improve the efficiency of renal biopsy procedures. Methods: We initiated a quality improvement project to implement pre-admission testing (PAT) for renal biopsy from 2016 to 2024 (until 15 April). Our evaluation focused on waiting times for admission, length of admission periods, hospitalization expenses, percentage of cases with no renal biopsy performed, incidence of severe bleeding due to renal biopsy, and percentage of cases with adequate tissue samples obtained. Additionally, we highlighted the time periods during the outbreak of SARS-CoV-2. Results: The highest annual case number was observed in time period 1 (168.3/year). Following the outbreak of SARS-CoV-2, there was a notable decrease in case numbers during time period 2 (119.8), which then increased to 143.0 in time period 3 (post-SARS-CoV-2 era). The mean waiting time was 13.72 ± 40.30 days for time period 1 and 10.00 ± 47.80 days for time period 2, without statistical significance. Following the implementation of PAT, patients now only need to wait approximately 0.76 days for admission, representing a significant reduction in waiting time. Subsequently, following the implementation of PAT, the waiting time decreased significantly to 2.09 ± 2.65 days. Additionally, hospitalization expenses per patient significantly decreased from approximately USD 69.62 ± 97.09 to USD 41.66 ± 52.82. The percentage of missed biopsy is significantly low (p < 0.001). Severe bleeding events (indicated as embolization and blood transfusion) were consistent across the three time periods (p = 0.617). Conclusions: The implementation of PAT can improve the pre-admission process for renal biopsy, resulting in decreased waiting times, fewer missed appointments, shorter admission durations, and reduced hospitalization expenses. We propose implementing PAT for outpatient individuals awaiting in-hospital renal biopsy procedures to mitigate delayed diagnosis, reduce pre-admission waiting periods, and streamline admission processes, thereby enhancing overall patient care efficiency.

Comparison of Complications between Total Intravenous Anaesthesia and Combined Intravenous and Inhalation Anaesthesia after Renal Biopsy in Children.

OBJECTIVE: The objective of this study was to examine the influence of total intravenous anaesthesia (TIVA) compared to combined intravenous and inhalation anaesthesia (CIIA) in paediatric patients undergoing renal biopsy. METHODS: A total of 86 children with nephrotic syndrome, acute glomerulonephritis, chronic glomerulonephritis, IgG nephropathy, systemic lupus erythematosus and purpura nephritis were selected from January 2018 to January 2023 in our hospital. All children were divided into the total intravenous anaesthesia group and intravenous inhalational anaesthesia group according to the anaesthesia method. The experimental group comprised 46 children with renal diseases who underwent static aspiration compound anaesthesia during renal biopsy at our hospital from January 2018 to January 2023. Conversely, the control group included 40 children with renal diseases who underwent total intravenous anaesthesia during renal biopsy at the hospital within the same period. Hemodynamic parameters, such as mean arterial pressure (MAP), heart rate (HR), and oxygen saturation (SPO2), were assessed at four different time points: Before anesthesia induction (T0), during anesthesia induction (T1), after anesthesia induction (T2), and at the conclusion of the surgery (T3). Puncture success rate, time to renal puncture, time to get out of bed, postoperative recovery from anaesthesia (including time to postoperative awakening and time to return to spontaneous respiration) and incidence of adverse anaesthetic reactions were also included. RESULTS: We observed notable variations in HR and MAP at T2 and T3, as well as SPO2 levels, duration of awakening from anaesthesia and time taken to resume spontaneous respiration between the two groups at T2 (p < 0.05). No statistically significant variances were detected between the two groups concerning adverse reactions to anaesthesia, puncture success rate, duration to renal puncture and time to mobilisation from bed (p > 0.05). CONCLUSIONS: In conclusion, compared with the total intravenous anaesthesia, the implementation of the sedation-aspiration-combined anaesthesia in renal biopsy in children with renal disease features less haemodynamic fluctuation, better postoperative anaesthesia recovery and does not increase the incidence of adverse reactions.

Infection as a trigger of acute, transient glomerular deposition of clonal immunoglobulins.

Glomerular deposition of monoclonal IgM, frequently in the form of intracapillary pseudothrombi, can be seen in Waldenström macroglobulinemia (WM) and type I cryoglobulinemia (CG). They are typically associated with plasma cell or B-lymphoid neoplasms, particularly lymphoplasmacytic lymphoma (LPL). While infection is a frequent trigger of mixed (type II and III) CG, its association with type I CG is uncommon. We report two cases in which striking lambda-chain-restricted IgM deposits and acute kidney injury (AKI) occurred in the setting of known or suspected systemic infections, with prompt resolution on treatment of the infection.

Protocol for a systematic review of the application of the kidney failure risk equation and Oxford classification in estimating prognosis in IgA nephropathy.

BACKGROUND: IgA nephropathy (IgAN) is a common cause of chronic kidney disease (CKD) and end-stage renal disease (ESRD). Outcomes are highly variable and predicting risk of disease progression at an individual level is challenging. Accurate risk stratification is important to identify individuals most likely to benefit from treatment. The Kidney Failure Risk Equation (KFRE) has been extensively validated in CKD populations and predicts the risk of ESRD at 2 and 5 years using non-invasive tests; however, its predictive performance in IgAN is unknown. The Oxford classification (OC) describes pathological features demonstrated on renal biopsy that are associated with adverse clinical outcomes that may also inform prognosis. The objective of this systematic review is to compare the KFRE with the OC in determining prognosis in IgAN. METHODS: A systematic review will be conducted and reported in line with PRISMA guidelines (PRISMA-P checklist attached as Additional file 1). Inclusion criteria will be cohort studies that apply the KFRE or OC to determine the risk of CKD progression or ESRD in individuals with IgAN. Multiple databases will be searched in duplicate to identify relevant studies, which will be screened first by title, then by abstract and then by full-text analysis. Results will be collated for comparison. Risk of bias and confidence assessments will be conducted independently by two reviewers, with a third reviewer available if required. DISCUSSION: Identifying individuals at the highest risk of progression to ESRD is challenging in IgAN, due to the heterogeneity of clinical outcomes. Risk prediction tools have been developed to guide clinicians; however, it is imperative that these aids are accurate and reproducible. The OC is based on observations made by specialist renal pathologists and may be open to observer bias, therefore the utility of prediction models incorporating this classification may be diminished, particularly as in the future novel biomarkers may be incorporated into clinical practice. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42022364569.

Emergency endovascular and percutaneous urological interventions: A pictorial review.

Emergency endovascular and percutaneous urological interventions encompass various diagnostic and therapeutic procedures to address various genitourinary conditions. These urological interventions are life-saving in addressing complications following biopsy, post-nephrectomy, post-transplant, and post-trauma. Compared to other surgical fields, there are relatively fewer urological emergencies. However, they require prompt radiological diagnosis and urgent interventions. This pictorial essay emphasizes various urological emergencies and urgent interventional management.

Growth arrest-specific protein 6 as a marker of nephritis in systemic sclerosis and juvenile systemic lupus erythematosus patients.

Background: Renal impairments commonly occur as a complication of autoimmune connective tissue diseases (CTDs). Therefore, early nephritis prediction is vital for patient outcomes. Growth Arrest-Specific Protein 6 (GAS6) was found to be upregulated in many types of inflammatory renal disease, including diabetic nephropathy.Aim: To evaluate GAS6 as a predictor of renal impairment in adults with systemic sclerosis (SSc) and children with systemic lupus Erythematosus (SLE).Methods: The study included 60 patients with SSc and 40 children with SLE. The serum level of GAS6 was measured using the ELISA technique. In adults with SSc, total proteins in 24-h urine concentration of >300 mg/24 h indicated renal inflammation, while in children with SLE, nephritis was diagnosed by abnormal renal pathology.Results: In SSc patients, GAS6 significantly increased in patients with proteinuria. GAS6 is an independent predictor of nephritis with an odds ratio (OR) of 1.06 and a 95% confidence interval (CI) of 1.0-1.1. at cutoff 12.2 ng/mL GAS6 predicted proteinuria with sensitivity 86.7% (95% CI: 59.5% to 98.3%), specificity 57.8% (95% CI: 42.1% to 72.3%), positive predictive value 40.6% (95% CI: 31.5% to 50.4%), negative predictive value 92.9% (95% CI: 77.7% to 97.73%), and accuracy 65.0% (95% CI: 51.6% to 76.9%). In SLE patients, Serum GAS6 did not differ significantly between children with and without lupus nephritis.Conclusion: GAS6 is an independent predictor of nephritis in patients with SSc. However, there is no association between GAS6 and nephritis in juvenile patients with SLE.

Glomerular Exostosin-Positivity is Associated With Disease Activity and Outcomes in Patients With Membranous Lupus Nephritis.

Introduction: The relationship of exostosin 1 and exostosin 2 (EXT1/EXT2) expression and outcomes in membranous lupus nephritis (MLN) was controversial. Methods: EXT1/EXT2 was performed by immunohistochemistry (IHC) in 283 consecutive patients with MLN. Clinicopathological characteristics and outcomes of EXT1/EXT2-positive patients were compared with EXT1/EXT2-negative patients. The primary end points were adverse renal events, including death, dialysis, and renal transplantation. Results: Of the patients with MLN, 29.3% were positive for EXT1/EXT2. The prevalence of EXT1/2-positive MLN was significantly higher in pure class V MLN than those for mixed class V MLN (44.2% vs. 19.4%, P < 0.001). For EXT1/EXT2-positive patients, the median time between onset of lupus and renal biopsy, and lupus nephritis and renal biopsy is shorter (6 [interquartile range, IQR: 2-25] months vs. 12 [IQR: 3-49] months, P = 0.008 and 3 [IQR: 2-18] months vs. 6 [IQR: 2-23] months, P = 0.039) and they had significantly lower systemic lupus erythematosus Disease Activity Index (SLEDAI) scores (P = 0.015) and lower serum creatinine levels (P < 0.001), higher hemoglobin (P = 0.006) as well as lower blood pressure. The EXT1/EXT2-positive patients had significantly fewer chronicity features (glomerulosclerosis, P < 0.001; interstitial fibrosis, P = 0.006; and tubular atrophy, P = 0.002) and fewer activity indicators (endocapillary hypercellularity, P = 0.012; cellular crescents, P = 0.007; and fibrocellular crescents, P < 0.001) on renal biopsy. After a median follow-up of 65 (28-126) months, EXT1/EXT2-positive patients were less likely to experience adverse renal events (2.4% vs. 16.0%, P = 0.001). Conclusion: Compared with EXT1/EXT2-negative patients, the EXT1/EXT2-positive patients presented with lower disease activity and were less likely to experience adverse renal events in relationship with the chronicity index.

Systemic vasculitis involving the kidney: the nephropathologist's point of view.

Kidneys are often targets of systemic vasculitis (SVs), being affected in many different forms and representing a possible sentinel of an underlying multi-organ condition. Renal biopsy still remains the gold standard for the identification, characterization and classification of these diseases, solving complex differential diagnosis thanks to the combined application of light microscopy (LM), immunofluorescence (IF) and electron microscopy (EM). Due to the progressively increasing complexity of renal vasculitis classification systems (e.g. pauci-immune vs immune complex related forms), a clinico-pathological approach is mandatory and adequate technical and interpretative expertise in nephropathology is required to ensure the best standard of care for our patients. In this complex background, the present review aims at summarising the current knowledge and challenges in the world of renal vasculitis, unveiling the potential role of the introduction of digital pathology in this setting, from the creation of hub-spoke networks to the future application of artificial intelligence (AI) tools to aid in the diagnostic and scoring/classification process.

[Automatic classification of immune-mediated glomerular diseases based on multi-modal multi-instance learning].

OBJECTIVE: To develop a multi-modal deep learning method for automatic classification of immune-mediated glomerular diseases based on images of optical microscopy (OM), immunofluorescence microscopy (IM), and transmission electron microscopy (TEM). METHODS: We retrospectively collected the pathological images from 273 patients and constructed a multi-modal multi- instance model for classification of 3 immune-mediated glomerular diseases, namely immunoglobulin A nephropathy (IgAN), membranous nephropathy (MN), and lupus nephritis (LN). This model adopts an instance-level multi-instance learning (I-MIL) method to select the TEM images for multi-modal feature fusion with the OM images and IM images of the same patient. By comparing this model with unimodal and bimodal models, we explored different combinations of the 3 modalities and the optimal methods for modal feature fusion. RESULTS: The multi-modal multi-instance model combining OM, IM, and TEM images had a disease classification accuracy of (88.34±2.12)%, superior to that of the optimal unimodal model [(87.08±4.25)%] and that of the optimal bimodal model [(87.92±3.06)%]. CONCLUSION: This multi- modal multi- instance model based on OM, IM, and TEM images can achieve automatic classification of immune-mediated glomerular diseases with a good classification accuracy.

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 Department 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.

Epidemiological, immunological, and treatment response profile of patients with lupus nephritis in Brazil.

BACKGROUND AND HYPOTHESIS: Brazil has the largest number of individuals of African descent outside Africa and a very admixed population. Among cases of lupus nephritis (LN) in the country, there are differences in incidence, and even in severity, depending on the location and characteristics of the population studied. The aim of this study was to describe the clinical and epidemiological characteristics of LN in Brazil, as well as to determine which of those characteristics would be risk factors for a poor renal prognosis. METHODS: This was a retrospective, descriptive observational study of patients diagnosed with LN who underwent kidney biopsy between 1999 and 2015 in the Nephrology Department of the Hospital das Clínicas, in São Paulo, Brazil. Data were collected from electronic medical records. RESULTS: We evaluated 398 patients, among who 94.1% and 77.7% tested positive for antinuclear antibodies and anti-DNA antibodies, respectively, whereas 33.7% showed the full-house pattern. The time from LN symptom onset to biopsy was <6 months in 47.5% (early biopsy group) and ≥6 months in 52.5% (late biopsy group). In the early biopsy group, the chronicity index was lower and the activity index was higher. Multivariate analysis showed that a higher chronicity index was the only independent risk factor for progression to requiring kidney replacement therapy. CONCLUSION: Late biopsy seems to be associated with negative renal outcomes in LN. However, it seems that a higher chronicity index is the main predictor of a poor renal outcome among patients with LN in Brazil.

Significance of the total renal chronicity score in predicting renal outcome in PLA2R-associated membranous nephropathy.

BACKGROUND: Phospholipase A2 receptor (PLA2R)-associated membranous nephropathy accounts for the majority of membranous nephropathy; however, few studies have determined the prognostic impact and clinical application of renal pathologic change on this disease. METHODS: A retrospective cohort study of 262 patients with PLA2R-associated membranous nephropathy was conducted. The total renal chronicity score calculated according to the degree of glomerulosclerosis, interstitial fibrosis, tubular atrophy, and arteriosclerosis was applied to evaluate renal chronicity. Baseline bias was adjusted by inverse probability weight when assessing the prognostic impact of chronicity, and multiple parameters were used to evaluate the application value of renal chronicity. RESULTS: During a median follow-up of 24.5 months, renal outcome (kidney function deterioration and/or end-stage kidney disease) was observed in 22 (8.40%) patients. Not only did a higher total renal chronicity score independently predict renal outcome [odds ratio (OR): 1.562, 95% confidence interval (CI) 1.073-2.273, P = 0.020], but non-minimal chronicity was also an independent risk factor for renal outcome (OR: 3.170, 95% CI 1.040-9.659, P = 0.042). Moreover, the membranous nephropathy risk classification in the Kidney Disease: Improving Global Outcomes (KDIGO) guideline integrated with non-minimal chronicity showed improvements in categorical net reclassification (0.174, 95% CI 0.012-0.335, P = 0.035), continuous net reclassification (0.462, 95% CI 0.087-0.838, P = 0.016), and integrated discrimination (0.019, 95% CI 0.003-0.035, P = 0.020) compared to the original classification. CONCLUSIONS: Renal chronicity is closely associated with renal outcomes in PLA2R-associated membranous nephropathy, and combining the KDIGO risk classification with chronicity scores may provide a more accurate prognostic prediction.

[Introduction to renal pathology]. / Einführung in die Nierenpathologie.

In recent decades, nephropathology has developed worldwide as a subspeciality of pathology, which requires special methodological and technical equipment to process the material and specific clinical and pathological expertise to interpret the findings. These special requirements mean that nephropathology is not available at all pathology institutes, but is carried out on a large scale in a few highly specialised centres. The history of nephropathology, or in a narrower sense the specialised histopathological examination of kidney biopsies, began in 1958 with the first use or performance of a kidney biopsy [1]. It thus replaced the practice of urinalysis, which had been common since the Middle Ages, as a diagnostic tool for kidney diseases. Specialised techniques such as immunofluorescence or immunohistology but also electron microscopy are required to assess specific renal changes, for which the examination of renal biopsies is one of the few remaining routine applications today. In Germany and German-speaking countries, the discipline developed thanks to the work of outstanding people in the field of pathology who were primarily involved in this discipline and had the necessary technical and human resources in their laboratories to ensure that these biopsies could be analysed.

The Clinicopathological Correlation and Outcome of Glomerulonephritis With Crescent: A Single-Center Study.

BACKGROUND: There is a lack of standardized treatments for patients with less than 50% crescents observed in their renal biopsies. This study aimed to analyze the crescent percentage, clinicopathological characteristics, and renal prognosis of glomerulonephritis (GN) cases with at least one crescentic lesion. MATERIALS AND METHODS: This retrospective cohort study was conducted at the Indira Gandhi Institute of Medical Sciences, Patna, from January 2016 to December 2020. Consecutive patients (aged between 18 and 65 years) with renal biopsy findings suggestive of GN and at least one crescent were included in the study. Demographic details and clinical presentation were collected from the medical records. RESULTS: A total of 145 patients were included. The mean (standard deviation (SD)) age was 33.06 (11.739) years. Hemoptysis was significantly higher in the ≥50% crescent group (P=0.011). Rapidly progressive glomerulonephritis (RPGN) was significantly higher in the ≥50% crescent group (P<0.001). There was a significant difference observed in mean creatinine (P=0.001), mean crescents (P<0.001), and mean urine polymerase chain reaction (PCR) (P=0.031). Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis was significantly higher in the ≥50% crescent group (P<0.001). Complete remission decreased as crescents increased. In GN with crescent, the presence of fibrous crescents (≥50%) is associated with a higher rate of treatment resistance (100%) compared to fibrocellular (58.33%) and cellular crescents (6.25%). In the ≥50% crescent group, death was significantly higher in patients with fibrous crescent age (57.14%). CONCLUSION: Crescent percentage and crescent age were found to be significantly related to greater risk of renal failure and resistance to treatment.

Frequency and timing of renal biopsy complications.

Background: Percutaneous renal biopsy is the primary diagnostic tool for renal diseases. In this study, we evaluated renal biopsy complications and the timing of complications. Methods: A cross-sectional study was performed on adult patients who underwent renal biopsy. The data gathering sheet collected patient characteristics. Complications were categorized as minor and major which needed an intervention. Data were analyzed using SPSS, and a p-value <0.05 was considered significant. Results: This cross-sectional study was conducted on 215 patients (mean age: 33.1±16.4 and 54.4%: women) who underwent percutaneous renal biopsy in Shiraz Nemazi Hospital for one year. Of the 298 complications that occurred, 90.2% were minors (56.1%of them microscopic hematuria). Moreover, 2 (0.7%) patients developed major complications and received a transfusion. In addition, most of the complications (98.9%, 295 ones) developed within 8 hours post-procedure. Only hemoglobin drop was significantly higher in women (41.0% vs. 21.4%, P=0.003). Conclusion: This study indicates that renal biopsy is a safe procedure; the results revealed that the significant post-biopsy complications were rare and occurred in the first 8 hours.