AUTHOR=Ling Chen , Wang Xiaolin , Chen Zhi , Fan Jianfeng , Meng Qun , Zhou Nan , Sun Qiang , Hua Lin , Gui Jingang , Liu Xiaorong 

TITLE=Altered B-Lymphocyte Homeostasis in Idiopathic Nephrotic Syndrome

JOURNAL=Frontiers in Pediatrics

VOLUME=7

YEAR=2019

URL=https://www.frontiersin.org/journals/pediatrics/articles/10.3389/fped.2019.00377

DOI=10.3389/fped.2019.00377

ISSN=2296-2360

ABSTRACT=<p><bold>Background:</bold> B-cell-deleted therapy has been successfully used for children with idiopathic nephrotic syndrome (INS), suggesting that B cells may be involved in the pathogenesis of INS. B cells are a heterogenous population comprised of subpopulations distinguished by their phenotypes. However, few studies have focused on the alteration of B-cell homeostasis in INS.</p><p><bold>Methods:</bold> We measured the levels of B-cell subsets in the blood of 87 INS children via flow cytometry, prior to treatment with steroids. INS patients were divided into steroid-sensitive nephrotic syndrome (SSNS) and steroid-resistant nephrotic syndrome (SRNS) groups based on their sensitivities to steroids after a one-month follow-up. Subsequently, we compared these INS patients with age- and sex-matched patients with relapse (<italic>n</italic> = 35) and remissions (<italic>n</italic> = 32), as well as healthy controls (<italic>n</italic> = 75).</p><p><bold>Results:</bold> We found that 65 SSNS patients exhibited an altered peripheral-blood B-cell-subset distribution, with increased levels of total, transitional, memory, IgM (immunoglobulin M) memory and switched-memory B cells compared to 22 SRNS patients. The proportion of total B cells was significantly higher in the SSNS group (22.1 ± 6.7% L, <italic>p</italic> &lt; 0.001) than in the SRNS, remission, and control groups. In contrast, the levels of B-cell subsets in SRNS patients were generally the same as those in remission patients and healthy controls. Patients in relapse presented elevated memory B cells compared to those in other groups. The area under the ROC (receiver operating characteristic) curve of transition B cells at initial onset for the prediction of SSNS was 0.907 (95% confidence interval, 0.835–0.979). The analysis rendered an optimal cut-off value of 2.05 (% Lymphocyte) corresponding to 79.1% sensitivity and 90.9% specificity.</p><p><bold>Conclusions:</bold> We observed and verified that B-cell subsets are significantly altered in children with SSNS. We propose that elevated transitional B cells may be a promising marker for predicting successful immunosuppressive therapy during the initial onset of INS. Further research is needed to determine the function of memory B cells in INS.</p>