title: Expression profile of BAFF in peripheral blood from patients of IgA nephropathy: Correlation with clinical features and Streptococcus pyogenes infection.
abstract: B cells are critically important for the pathogenesis of IgA nephropathy (IgAN). The present study aimed to investigate the abundance of B cell activating factor (BAFF), which belongs to the tumor necrosis factor superfamily, in the peripheral blood of patients with IgAN. The different forms of BAFF in peripheral blood and its association with clinical features and immunological factors were analyzed. mRNA levels of BAFF and other associated genes in the peripheral blood mononuclear cells (PBMCs) of patients with IgAN and controls were analyzed by quantitative polymerase chain reaction. Cellular BAFF proteins in PBMCs and plasma soluble BAFF proteins were measured by western blot analysis and ELISA, respectively. PBMCs from patients were stimulated with Streptococcus pyogenes (S. pyogenes) ex vivo for the BAFF secretion assay. The data demonstrated that, although mRNA levels of BAFF in PBMC were not significantly increased in patients with IgAN, they were positively associated with those of a proliferation inducing ligand (APRIL), Toll‑like receptor (TLR)2, TLR4 and TLR7. The cellular BAFF protein in PBMCs was not upregulated. Plasma BAFF protein levels in patients with IgAN (n=76) were significantly decreased compared with controls. However, plasma BAFF levels were positively associated with serum creatinine, proteinuria, uric acid and group A Streptococcus infection index in patients with IgAN. In patients with IgAN, plasma BAFF concentrations were markedly higher in those with more severe renal tubular atrophy/interstitial fibrosis and global glomerulosclerosis. Furthermore, BAFF production in PBMCs of patients with IgAN was increased following S. pyogenes stimulation ex vivo. In conclusion, plasma BAFF levels in patients with IgAN were associated with renal function and disease activity. S. pyogenes infection was closely associated with BAFF production in patients with IgAN.
authors.affiliation: Translational Medical Center, The First Affiliated Hospital of Sun Yat‑sen University, Guangzhou, Guangdong 510000, P.R. China.
authors.forename: Nuoyan
authors.initials: N
authors.lastname: Zheng
authors.affiliation: Department of Nephrology, The First Affiliated Hospital of Sun Yat‑sen University, Guangzhou, Guangdong 510000, P.R. China.
authors.forename: Jinjin
authors.initials: J
authors.lastname: Fan
authors.affiliation: International Travel Health Care Center, Entry & Exit Inspection and Quarantine Bureau of Guangdong Guangzhou, Guangzhou, Guangdong 510000, P.R. China.
authors.forename: Bing
authors.initials: B
authors.lastname: Wang
authors.affiliation: Translational Medical Center, The First Affiliated Hospital of Sun Yat‑sen University, Guangzhou, Guangdong 510000, P.R. China.
authors.forename: Dongxian
authors.initials: D
authors.lastname: Wang
authors.affiliation: Clinical Laboratory, The First Affiliated Hospital of Sun Yat‑sen University, Guangzhou, Guangdong 510000, P.R. China.
authors.forename: Pinning
authors.initials: P
authors.lastname: Feng
authors.affiliation: Department of Nephrology, The First Affiliated Hospital of Sun Yat‑sen University, Guangzhou, Guangdong 510000, P.R. China.
authors.forename: Qiongqiong
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Department of Nephrology, The First Affiliated Hospital of Sun Yat‑sen University, Guangzhou, Guangdong 510000, P.R. China.
authors.forename: Xueqing
authors.initials: X
authors.lastname: Yu
mesh_terms: D000328:Adult; D053264:B-Cell Activating Factor / Q000097:blood* / Q000235:genetics; D005260:Female; D005786:Gene Expression Regulation; D005922:Glomerulonephritis, IGA / Q000097:blood / Q000150:complications* / Q000235:genetics / Q000473:pathology; D006801:Humans; D007668:Kidney / Q000473:pathology; D007963:Leukocytes, Mononuclear / Q000378:metabolism / Q000473:pathology*; D008297:Male; D012333:RNA, Messenger / Q000235:genetics; D013290:Streptococcal Infections / Q000097:blood / Q000150:complications* / Q000235:genetics / Q000473:pathology; D013297:Streptococcus pyogenes / Q000302:isolation & purification*; D053300:Tumor Necrosis Factor Ligand Superfamily Member 13 / Q000235:genetics
chemical_list: D053264:B-Cell Activating Factor; D012333:RNA, Messenger; C505719:TNFSF13B protein, human; D053300:Tumor Necrosis Factor Ligand Superfamily Member 13