Diagnostic Value of Sox9 Staining To Identify Early Recurrence of Focal and Segmental Glomerulosclerosis (FSGS) after Renal Transplant
Wael Sakr, Dongping Shi, Xu Zeng. Wayne State University, Detroit, MI
Background: Recurrence of FSGS after renal transplant is present with proteinuria initially. Diagnosis of FSGS is made mainly by detection of segmental sclerosis in glomerular capillary tuft, an alteratin that is ofter “very focal and segmental" in early stage, therefore diagnosis can be missed due to sampling. Recent data suggest that FSGS is an irreversible podocyte injury by TGF-ß mediated apoptosis then fibrogenesis and sclerosis. Sox9 is a transcriptional factor and one of the downstream targets of TGF-ß. Previous reports indicate that Sox9 staining is pos in FSGS in segmental sclerotic and non-sclerotic glomeruli but lack of detailed information for its clinical use. The purpose of this study is to evaluate the value of Sox9 in diagnosis of early recurrence of FSGS post renal transplant.
Design: All patients who received renal transplant in Detroit Medical Center for a diagnosis of FSGS between 2004-2010 and who were clinically suspected to have recurrent FSGS based on proteinuria, and underwent multiple follow-up biopsies were included in this study. Immunohistochemistry staining for Sox9 on fixed tissues of all biopses was recorded as positive or negative. The relationship between Sox9 staining patterns and recurrence of FSGS were evaluated.
Results: Thirteen patients qualified during study period of whom 8 patients had 3 to 7 biopsies with adequate tissue for immunostaining. Pococyte is stained by Sox9 in FSGS case. Seven of 8 patients showd unique Sox9 staining (positive or negative) pattern through their multiple biopsy with/without FSGS. One patient had negative Sox9 staining in initially biopsy that turned positive in follow up biopsy demonstating FSGS. Figure 1 summarized the result of Sox9 staining in podocyte with 80% sensitivity and 66.7specificity. The positive and negative predictive value is 80% and 66.7% respectively.
No staining in PEC is noted.
Conclusions: Our data suggest that Sox9 staining in podocyte is a reliable marker for the detection of early recurrent of FSGS in renal allograft and have high sensitivity and positive predictive value, finding that need further comfirmation by studies with large number of patientis.
Category: Kidney (does not include tumors)
Wednesday, March 21, 2012 1:00 PM
Poster Session VI # 279, Wednesday Afternoon