Abstract: TH-PO570
Establishing Methods to Predict Responsiveness to Steroid Therapy at Disease Onset of Idiopathic Nephrotic Syndrome in Children
Session Information
- Glomerular Diseases: Omics, Biomarkers, and Tools
October 24, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1401 Glomerular Diseases: Mechanisms, including Podocyte Biology
Authors
- Yajima, Chikage, Gunma Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Maebashi, Gunma, Japan
- Kobayashi, Yasuko, Gunma Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Maebashi, Gunma, Japan
- Yamasaki, Yoko, Gunma Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Maebashi, Gunma, Japan
- Takizawa, Takumi, Gunma Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Maebashi, Gunma, Japan
Background
Steroid responsiveness is important in predicting the long-term prognosis of kidney function in children with idiopathic nephrotic syndrome . However, there is no method for predicting steroid responsiveness at disease onset in patients with massive proteinuria. Patients require more than 4 weeks of steroid treatment to diagnose steroid-resistant nephrotic syndrome (SRNS); therefore, complications from refractory edema and side effects of steroid therapy could be severe in SRNS patients. There is an urgent need to establish methods that enable the prediction of patient responsiveness to steroid treatment at disease onset.
Methods
We investigated the activation of αvβ3 integrin and Rho GTPases (RhoA, Rac1, and Cdc42), and cell migration activity utilizing healthy human podocyte cell lines (ciPods). Differentiated ciPods were stimulated with serum obtained from patients with steroid sensitive nephrotic syndrome (SSNS, n=14) and SRNS (n=9) at relapse. Activated αvβ3 integrin expressed on the basement membrane of ciPods was measured using the immunofluorescent antibody method with total reflection illumination fluorescence microscopy. Cell lysates were collected after stimulation with serum to quantify active GTPases using enzyme-linked immunosorbent assay. Cell migration was evaluated using scratch assay.
Results
SRNS relapse serum activated αvβ3 integrin in ciPods, whereas SSNS relapse serum did not induce the activation. Relative fluorescence intensity of active αvβ3 integrin was significantly higher with SRNS serum stimulation than with SSNS serum (p=0.0012). The area under the receiver operating characteristic curve was 0.8889, and the cut-off point was 0.166, with 78% sensitivity and 93% specificity. The relative absorbance of active Cdc42, which promotes cell motility, showed no significant difference between SSNS and SRNS stimulation (p=0.3939); however, in the migration assay, ciPods tended to migrate faster with SRNS serum stimulation than with SSNS serum stimulation (p=0.0556).
Conclusion
The αvβ3 integrin activation level on the ciPods basement membrane surface may be useful in differentiating SRNS from SSNS. The ciPods migration assay can be used supplementally to differentiate between SSNS and SRNS. Further investigations using patient serum samples at disease onset are required.
Funding
- Government Support – Non-U.S.