title: Infiltrations of plasma cells in synovium are highly associated with synovial fluid levels of APRIL in inflamed peripheral joints of rheumatoid arthritis.
abstract: Infiltration of plasma cells can be a histopathological hallmark of articular synovium with rheumatoid arthritis (RA). A proliferation-inducing ligand (APRIL) may have key roles in homeostasis and development of B cells, and the differentiation of B cells into plasma cells. This study was designed to explore the relationships between the infiltrations of plasma cells in synovium and the synovial fluid levels of APRIL in inflamed peripheral joints of RA. Synovium and synovial fluid were sampled from 21 RA patients underwent arthroscopic synovectomy for inflamed peripheral joints. The variants of rheumatoid synovium were classified into the follicular and diffuse synovitis by hematoxylin and eosin staining, and the infiltrations of plasma cells in rheumatoid synovium were quantified under the light microscope. The synovial fluid levels of APRIL were measured with the enzyme-linked immunosorbent assay. The mean number of infiltrating plasma cells in synovium and the mean synovial fluid level of APRIL were significantly increased in follicular synovitis compared with those in diffuse synovitis (P = 0.009, and P = 0.018, respectively), and there was a highly positive association between the infiltrations of plasma cells and the synovial fluid levels of APRIL among all of the RA patients (Rs = 0.776, P < 0.001). These findings suggest that the local production of APRIL may be associated with the ectopic lymphoid neogenesis in rheumatoid synovium and may have a role in contributing to the infiltration of plasma cells in synovium within inflamed peripheral joints of RA.
authors.affiliation: Department of Clinical Immunology, State Key Discipline of Cell Biology, Xijing Hospital, Forth Military Medical University, 710032, Xi'an, China. dongwj@fmmu.edu.cn
authors.forename: Weijia
authors.initials: W
authors.lastname: Dong
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Li
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.forename: Ping
authors.initials: P
authors.lastname: Zhu
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D049109:Cell Proliferation; D002634:Chemotaxis, Leukocyte / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007596:Joints / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D008221:Lymphoid Tissue / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010950:Plasma Cells / Q000378:metabolism* / Q000473:pathology; D013582:Synovial Fluid / Q000276:immunology / Q000378:metabolism*; D013583:Synovial Membrane / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D013585:Synovitis / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D053300:Tumor Necrosis Factor Ligand Superfamily Member 13 / Q000032:analysis / Q000378:metabolism*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D053300:Tumor Necrosis Factor Ligand Superfamily Member 13