Study of Immunohistochemical and Ultrastructural Markers in Podocytes from Post-Transplant Biopsies

• Grant number: 25/14153-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2025
• End date: September 30, 2026
• Field of knowledge: Health Sciences - Medicine - Pathological Anatomy and Clinical Pathology
• Principal Investigator: Daniela Cristina dos Santos Souza
• Grantee: Cecília Ortiz Rezende
• Host Institution: Faculdade de Medicina (FMB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Renal transplantation (RT) is the treatment of choice for end-stage chronic kidneydisease (CKD); however, it is a complex surgical procedure subject to variousclinical and surgical complications. In this context, considering the need toexpand the availability of donor kidneys while maintaining organ quality andlongevity, there is a clear necessity for further studies to assist in establishingpotential prognostic criteria for improved graft survival.Proteinuria is recognized as a prognostic criterion for the survival of renalallografts. Regarding proteinuria occurring within one year post-transplant, itsprevalence ranges from 15% to 30%, and graft failure in patients with suchcondition is 2.3 to 3.5 times higher, with a twofold increased risk of mortalitycompared to patients without proteinuria.Podocytes are specialized cells located in the renal filtration unit, the glomerulus.They possess filtration slits that envelop fenestrated glomerular capillaries.Together with the glomerular basement membrane (GBM), these structures formthe glomerular filtration barrier. Podocytes adhere to the GBM via focal adhesioncomplexes and cell surface receptors that facilitate interconnections betweenpodocytes and endothelial cells, thereby establishing an effective filtration barrierthat prevents proteinuria.Given this, the present study aims to investigate podocytes, which arefundamental for the stability of the glomerular basement membrane and arecritical components in maintaining the selective filtration barrier of the kidney,thereby prevnting glomerular proteinuria. We will analyze the expression ofpodocyte immunohistochemical markers-nephrin, actin, endothelial growthfactor, C2AP, and podocin-in renal transplant recipients to establish correlationsbetween glomerular podocyte alterations and late-onset proteinuria.Selected cases for immunohistochemical analysis will also undergoultrastructural examination via transmission electron microscopy to assesspodocyte morphology in the glomerular basement membrane. This will be aprospective study involving analysis of renal transplant biopsies using lightmicroscopy, immunohistochemistry, and transmission electron microscopy.Concurrently, clinical and epidemiological factors related to the study will beanalyzed, including a detailed description of immunosuppressive medicationsadministered at the time of biopsy