title: Up-regulation of cellular FLICE-inhibitory protein in peripheral blood B lymphocytes in patients with systemic lupus erythematosus is associated with clinical characteristics.
abstract: BACKGROUND
  Systemic lupus erythematosus (SLE) is an autoimmune disease which is involved in T- and B-lymphocyte-mediated autoimmunity. Apoptosis contributes to the maintenance of lymphocytes homeostasis and the deletion of autoreactive cells in SLE. Although there is evidence that cellular FLICE-inhibitory protein (c-FLIP), an antiapoptosis protein, is increased in human lupus T cells to keep them from apoptosis, but the expression of apoptosis-regulatory protein c-FLIP in SLE B lymphocytes remains unknown.
  
  
  OBJECTIVE
  To study the expression of c-FLIP in peripheral blood B lymphocytes in SLE patients and to investigate the relationship among the expression of c-FLIP in peripheral blood B lymphocytes in SLE patients, clinical manifestation and the levels of interleukin-4 (IL-4) and IL-10.
  
  
  METHODS
  In this study, we detected the expression of c-FLIP in peripheral blood B lymphocytes in SLE patients by flow cytometry and the levels of IL-4 and IL-10 in SLE serum samples by enzyme-linked immunosorbent assay and analysed their relationship with clinical characteristics.
  
  
  RESULTS
  We observed a significantly higher percentage of c-FLIP in peripheral B cells in SLE patients with active disease when compared to inactive ones and healthy controls. And the expression of c-FLIP in lupus peripheral B cells showed positive correlations with SLEDAI, erythrocyte sedimentation rate, C-reactive protein, antinucleosome antibody titre, IL-4, and IL-10, and negative correlation with white blood cell count. Patients with lupus nephritis had higher levels of c-FLIP in peripheral B cells than patients without lupus nephritis.
  
  
  CONCLUSIONS
  Our data show that overexpression of c-FLIP is relevant to the activity and severity of SLE. Its overexpression might play a role in preventing B cell from apoptosis in SLE. The cause of c-FLIP overexpression may be due to the increase of IL-4 and IL-10 levels in SLE patients.
authors.affiliation: Department of Dermatology, Affiliated Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: J
authors.initials: J
authors.lastname: Tao
authors.forename: J
authors.initials: J
authors.lastname: Dong
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.forename: Y-Q
authors.initials: YQ
authors.lastname: Liu
authors.forename: J
authors.initials: J
authors.lastname: Yang
authors.forename: Y
authors.initials: Y
authors.lastname: Wu
authors.forename: L
authors.initials: L
authors.lastname: Li
authors.forename: G-X
authors.initials: GX
authors.lastname: Shen
authors.forename: Z-J
authors.initials: ZJ
authors.lastname: Tan
authors.forename: Y-T
authors.initials: YT
authors.lastname: Tu