Abstract

The diagnosis of renal pathologies, especially glomerulopathies, requires a clinical suspicion and also the performance of a renal biopsy with its respective histopathological study. This includes light microscopy, electron microscopy and immunofluorescence; all these techniques help us to reach a conclusive diagnosis.

Renal immunofluorescence analysis is essential and not only shows the deposition of immunocomplexes, but also confirms the immunological mechanism involved in the disease.

The immunofluorescence technique on fresh, non-fixed, frozen kidney tissue (IF-F) has been the gold standard technique for more than 60 years; however, an alternative technique is immunofluorescence in fixed and paraffin- embedded sections (IF-P), which uses the principle of traditional immunohistochemistry, unmasking the antigens with heat or enzymatic digestion. IF-P has been successfully used as a salvage technique for renal biopsies and lately it is used as a valid technique for diagnosis, especially if the infrastructure, material, or fresh tissue is not available to carry out frozen sections.

The aim of this review is to learn about the handling of renal biopsies for immunofluorescence study, antigen retrieval methods and the usefulness of IF-P in the diagnosis of renal pathology.

Keywords: Kidney biopsy; Paraffin immunofluorescence; Antigen retrieval; Direct immunofluorescence; Kidney pathology