title: Ratio of T helper to regulatory T cells in synovial fluid and postoperative joint laxity after allograft anterior cruciate ligament reconstruction.
abstract: BACKGROUND
  Arthroscopic anterior cruciate ligament (ACL) reconstruction with allograft may vary in instrumented laxity compared with autograft. T helper (Th) cells (CCR4+CCR6+Th) and regulatory T (Treg) cells are important in the early stage of immunologic reactions. It is unknown whether the ratio of CCR4+CCR6+Th to Treg is imbalanced and if it correlates with early postoperative laxity after ACL allograft reconstruction. We investigated the ratio and functional influence between these cells and the correlation with postoperative anterior knee laxity.
  
  
  METHODS
  In 40 patients who experienced unilateral arthroscopy-assisted ACL reconstruction, the ACL graft was an allograft in 20 patients and autograft in 20 patients. Maximum manual anterior tibiofemoral laxity measurements were performed with arthrometry testing. The phenotypes of CCR4+CCR6+Th and Treg cells of peripheral blood and synovial fluid from the two patient groups were determined by flow cytometry. The functionality of isolated Treg cells and effector T cells was quantified in (3)H-thymidine proliferation assays.
  
  
  RESULTS
  Both CCR4+CCR6+Th and Treg cells were significantly increased in the synovial fluid in the allograft group and were correlated with anterior knee laxity. The ratio of CCR4+CCR6+Th to Treg cells in the synovial fluid was positively correlated with laxity. Synovial CD4+CD25+ Treg cells displayed an increased suppressive capacity compared with blood CD4+CD25+ Treg cells. Activated responder T cells from the synovial fluid were less susceptible to CD4+CD25+ T cell-mediated suppression than were responder cells from blood.
  
  
  CONCLUSIONS
  The ratio of CCR4+CCR6+Th to Treg cells in the synovial fluid was correlated with anterior laxity after ACL allograft reconstruction.
authors.affiliation: Department of Orthopaedics, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Yang
authors.forename: Zhengzheng
authors.initials: Z
authors.lastname: Zhang
authors.forename: Bin
authors.initials: B
authors.lastname: Song
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.forename: Lihui
authors.initials: L
authors.lastname: Wang
authors.forename: Weiping
authors.initials: W
authors.lastname: Li
authors.forename: Huiyong
authors.initials: H
authors.lastname: Shen
mesh_terms: D000293:Adolescent; D000328:Adult; D059549:Anterior Cruciate Ligament Reconstruction / Q000009:adverse effects*; D001182:Arthroscopy / Q000009:adverse effects*; D015415:Biomarkers / Q000032:analysis; D001696:Biomechanical Phenomena; D049109:Cell Proliferation; D002478:Cells, Cultured; D016009:Chi-Square Distribution; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping / Q000379:methods; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007593:Joint Instability / Q000209:etiology* / Q000276:immunology / Q000503:physiopathology; D007719:Knee Joint / Q000276:immunology / Q000503:physiopathology / Q000601:surgery*; D008213:Lymphocyte Activation; D008297:Male; D010641:Phenotype; D016059:Range of Motion, Articular; D054398:Receptors, CCR4 / Q000032:analysis; D054399:Receptors, CCR6 / Q000032:analysis; D013582:Synovial Fluid / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000276:immunology*; D058504:Th17 Cells / Q000187:drug effects / Q000276:immunology*; D013997:Time Factors; D014182:Transplantation, Autologous; D014184:Transplantation, Homologous; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D015415:Biomarkers; C515354:CCR4 protein, human; C106311:CCR6 protein, human; D007166:Immunosuppressive Agents; D054398:Receptors, CCR4; D054399:Receptors, CCR6