Differences in Pathologic Findings and Gene Expressions of Renal Tissue according to Steroid Responsiveness in Adult-Onset Minimal Change Disease

Park, Sun Young; Han, Seung Hyeok; Oh, Hyung Jung; Kim, Seung Jun; Yoo, Dong Eun; Lee, Han Sung; Lee, Tae Hee; Moon, Sung Jin; Choi, Hoon Young; Han, Dae Suk; Kang, Shin Wook

Abstract

PURPOSE: Compared to children, adult MCD patients tend to have a slower response to steroids, however, little is known about the relationships between pathologic findings or the expression of certain gene and the response to steroid treatment in adult-onset MCD. This study was undertaken to investigate the differences in pathologic findings and the mRNA expression of nephrin and glucocorticoid receptor (GCR) in renal tissue according to steroid responsiveness in adult-onset MCD.
METHODS
Twenty-eight adult patients who presented with idiopathic nephrotic syndrome at our institution and fulfilled the criteria for MCD clinically and pathologically were chosen for this study. Based on the response to steroid treatment, patients were divided into two groups: early responders (ER) in whom CR was achieved within 4 weeks of steroid treatment; late responders (LR) in whom CR was achieved after 4 weeks of steroid treatment.
RESULTS
Of the 28 patients, ER consisted of 20 patients. Time to CR was significantly shorter in ER compared to LR (16.5+/-0.9 vs. 52.0+/-4.9 days, p<0.01). The proportion of patients with minimal IgM deposition on immunofluorescence was significantly higher in LR compared to ER (75.0% vs. 30.0%, p<0.01). On the other hands, the mRNA expression of GCR, assessed by real time-PCR, was significantly lower in LR than that in ER (p<0.005), whereas nephrin mRNA expression was not different between the two groups.
CONCLUSION
The presence of glomerular IgM deposition and the amount of GCR in renal tissue may be useful predictors of steroid responsiveness in adult MCD patients.