Evaluation of immunohistochemical markers CD44 and PAX8 in diagnosis of Focal Segmental Glomerulosclerosis suspected cases and its differentiation from Minimal Change disease in patients with nephrotic syndrome

Abstract

Abstract Background Expression evaluation of specific markers PAX8 and CD44 on kidney podocyte cells or their progenitor cells can be very helpful in diagnosing and differentiating between types of podocytopathies. In present study, the positivity of immunohistochemical markers CD44 and PAX8 in parietal epithelial cells (PECs) was evaluated to diagnose suspected cases of Focal Segmental Glomerulosclerosis (FSGS) and differentiate it from minimal change disease (MCD). Methods This cross-sectional study was conducted on patients who underwent kidney biopsy due to nephrotic syndrome. 42 FSGS samples and 36 MCD samples were selected and biopsies were evaluated for CD44 and PAX8 markers. Suitable blocks for immunohistochemical staining that had enough tissue were selected and evaluated. Results The expression frequency of PAX8 marker in group with FSGS was estimated as 97.6% and in group with MCD as 52.8%, which was significantly higher in FSGS group. Also, regarding the expression of CD44, in two groups with FSGS and MCD, respectively, 1 + cases equal to 26.2% and 94.4%, 2 + cases equal to 40.5% and 5.6%, and 3 + cases equal to 33.3% and 0.0%, which indicated the higher intensity of CD44 expression in FSGS group compared to MCD. Conclusions The expression of CD44 in FSGS was influenced by patients age and a direct and significant relationship was observed. The increase in amount and intensity of two markers PAX8 and CD44 expression in PEC cells in patients with FSGS shows high sensitivity of these markers in diagnosis of FSGS and the decrease in expression level in MCD can play an important role in differentiating between types of podocytopathy disorders.