Clinicopathologic and ultrastructural findings of hereditary nephritis; a 16-year single center survey in Iran

Introduction: Hereditary nephritis is an umbrella term for a group of congenital childhood diseases including but not limited to Alport syndrome, thin basement membrane disease, and Fabry disease. Objectives: The purpose of this study was a clinicopathologic investigation of Alport syndrome, thin basement membrane disease, and Fabry disease with a focus on the role of electron microscopy and toluidine blue staining in diagnosis. Patients and Methods: In this cross-sectional study, we investigated kidney biopsies with a final diagnosis of either Alport syndrome, thin basement membrane disease or Fabry disease from 2001 to 2016. Electron microscopy and light microscopy were done and the clinical and paraclinical data were extracted from the patients’ medical charts. Electron microscopy role was assessed in terms of necessary, helpful or non-necessary, while correlations between clinical and para-clinical data were determined using appropriate statistical tests. Results: Among the 2865 kidney biopsies, there were 22 patients of hereditary nephritis including 15 (0.52%) Alport syndrome, 5 (0.17%) thin basement membrane disease and 2 (0.07%) Fabry disease diagnosed by electron microscopy. Electron microscopy was essential for the diagnosis of 19 (86.4%) cases, helpful for 3(13.6%) and there was no case for which electron microscopy was non-necessary. The patients’ mean age was 16.1 ± 9.0 years. The most common finding in Alport syndrome was proteinuria (86.7%) followed by hematuria (60.0%). Conclusion: Considering the rate of misdiagnosis of hereditary nephritis using light microscopy and clinical findings alone, electron microscopy study and toluidine blue staining has an essential role in the precise diagnosis in these patients. With regard to the progressive nature of these diseases, prompt diagnosis using electron microscopy is pertinent for therapeutic decisions.