CD44 Staining Distingushes Focal-Segmental Glomerulosclerosis (FSGS) from Minimal Change Disease (MCD) in Pediatric Nephrotic Syndrome
Wael Sakr, Xu Zeng. Wayne State University, Detroit, MI
Background: Beside MCD, FSGS is a significant cause of steroid resistant nephrotic syndrome in children. Distinguishes FSGS from MCD is based mainly on the detection of segmental sclerosis in glomerular capillary tuft. Because of the "focal" nature of FSGS, the segmental sclerosis may be missed by sampling error. No reliable biological marker for detecting FSGS is available currently. A body of evidence indicates that FSGS is caused by loss of podocytes, which have limited regenerative capacity. Parietal epithelial cells (PEC) have been proposed to be the stem cells and serve for transition to podocytes. CD44 is a glocoprotein involved in cell adhesion and migration thus a marker for functionally active PEC. Recent studies have been showed that CD44 staining is positive in recurrent FSGS in renal transplantation, but negative in MCD. The purpose of this study is to evaluate the value of CD44 staining in diagnosis of FSGS in pediatric patients with nephrotic syndrome.
Design: Pediatric patients who had "paired-biospy", initial at which diagnosis of "MCD" is established and then a follow-up biopsy due to steroid resistant nephrotic syndrome, with diagnosis of FSGS/MCD in Children's Hospital of Michigan during 2004-2010 were considered for our study. Immunohistochemistry staining for CD44 was performed on blank sections of paraffin blocks in each case. CD44 staining in PEC and podocytes were recorded as positive or negative.
Results: Seven patients had "paired-biopsy" in the study period and 4 patients had adequate tissue suitable for immunostaining. Neither PEC nor podocyte show CD44 staining in initial biospy in these 4 patients. In follow-up biospy, the CD44 staining in PEC is positive in FSGS patients (2/2, 100%) but negative in MCD. CD44 staining in podocyte was also detected in FSGS (2/2, 100%) and MCD (1/2, 50%).
Conclusions: Our data suggest that CD44 staining in PEC is better than in podocyte for the assessing the risk of MCD to evolve to FSGS and may be a useful marker for distinguishing early FSGS from MCD. Study with large numbers are needed to support these observations.
Category: Kidney (does not include tumors)
Wednesday, March 21, 2012 1:00 PM
Poster Session VI # 277, Wednesday Afternoon