Defining the etiological, clinical and demographic characteristics of patients aged 0-18 years who went kidney biopsy in the department of pediatric nephrology between 2005-2021

Introduction and Objective: In our study, we aimed to evaluate the demographic characteristics of the patients who were followed up in our Department and underwent kidney biopsy, the frequency of renal diseases based on histopathological diagnosis, the relationship between clinical and histopathological findings, and complications related to kidney biopsy. Cases and Methods : Patients aged 0-18 years, who underwent percutaneous kidney biopsy between 2005-2021 and whose clinical information was available, were included in the retrospective study conducted at KTU Faculty of Medicine, Department of Pediatric Nephrology. Patients who underwent kidney biopsy due to malignancy, mass or metastasis were excluded from the study. Information about the patients, biopsy indications and pathology results were obtained by the patient files and computer based patient data system. Patients; gender, age, clinical features, biopsy indications, histopathological results and laboratory values were recorded. These results were evaluated and compared with in the groups and similar published datas. Results: It was observed that 177 percutaneous kidney biopsies were performed on 140 patients in a seventeen-years period. In our study, native and transplant kidney biopsy indications and results were evaluated together. Of the biopsies performed, 172 (97%) were native kidneys and 5 (3%) were transplant kidney biopsies. Primarily, the first biopsy data of 140 patients were analyzed. Repeated biopsies were also evaluated as second, third and fourth kidney biopsy histopathology results. 72 (51.4%) of the patients were girls and 68 (48.6%) were boys. The average age of girls was 10.4±4.5, the average age of boys was 10.6±4.6, and the average age of all patients was 10.5±4.5. The most common indication for biopsy were nephrotic syndrome (25.7%), AKI (18.6%), asymptomatic urinalysis abnormalities (16.4%), subsequently. When the histopathological results of kidney biopsies were evaluated, it was determined that primary glomerular diseases (%50) were the most common diagnosis. The most common histopathological diagnosis in this group were MesPGN (22.1%), IgAN (10.7%), MPGN (7.1%), and FSGS (4.3%), subsequently. Secondary glomerular diseases was the second most common histopathological diagnosis group. Included diseases in this group were LN (Lupus nephritis) (3%) and IgA vasculitis nephritis (3%). Tubulointerstitial diseases were detected thirdly (12.2%). All patients were evaluated via USG for hemorrhagic complications, 24 hours after biopsy. Clinically significant perinephric hematoma (>10 mm), were detected in 15% of the patients. In the vast majority of cases were followed up only resting. There were no serious complications such as surgical intervention, nephrectomy, respiratory arrest, or death during and after the procedure. Conclusion: Percutaneous kidney biopsy is an effective diagnostic method that has been used in children and adolescents for many years. It provides prognostic value in many kidney diseases and guides treatment options. In the our 17 years study period, we evaluated that kidney biopsy is a safe and minimally invasive procedure moreover contributes to diagnosis, treatment plan and prediction of prognosis. Keywords: Percutaneous kidney biopsy, diagnosis, etiology, glomerulonephritis, perinephric hematoma, children