Glomerular parietal epithelial expression of CD44 in minimal change nephrotic syndrome and primary focal segmental glomerulosclerosis: A clinico-pathological study.

Introduction: Minimal change nephrotic syndrome (MCNS) and focal segmental glomerulosclerosis (FSGS) are the two common causes of nephrotic syndrome (NS) in both children and adults with overlapping clinical features, but with distinct prognostic and therapeutic implications. The distinction between these relies entirely on histopathology, which can sometimes be difficult. CD44 is expressed by activated parietal epithelial cells, plays a role in matrix deposition and thus in the pathogenesis of FSGS.

Aims: To assess the expression of CD44 in MCNS and FSGS and to evaluate its association with the known clinical and histopathological prognostic factors.

Materials and methods: Thirty cases each of MCNS and FSGS were studied. The clinical, laboratory, histopathological, and CD 44 immunohistochemical data were recorded. The findings were analyzed and correlated. A P value of < 0.05 was considered statistically significant.

Results: Statistical association was noted between CD44 positivity and serum creatinine (p = 0.031), estimated glomerular filtration rate (p = 0.040), segmental sclerosis (p < 0.001), tubular atrophy (p = 0.027), interstitial fibrosis (p = 0.027), and histological diagnosis (p < 0.001). The sensitivity, specificity, positive predictive, and negative predictive values were 90%, 76.67%, 79.41% and 88.46%, respectively.

Conclusions: CD44 immunostain can effectively distinguish MCNS from FSGS. The congruent results of CD44 positivity with known prognostic factors support the possibility of using the CD44 marker as a predictive tool in selecting high-risk patients and offering appropriate therapeutic measures.