title: Increased circulating follicular helper T cells and activated B cells correlate with disease severity in patients with psoriasis.
abstract: BACKGROUND
  Follicular Helper T (TFH) Cells are a population of recently discovered CD4(+) T cells involved in autoimmune diseases. However, the contribution of TFH cells in patients with psoriasis remains unknown.
  
  
  OBJECTIVE
  We aimed to investigate the levels of TFH cells, B cells and their clinical relevance in patients with psoriasis.
  
  
  METHODS
  Using multi-colour flow cytometry, we detected different subsets of TFH cells and B cells in the peripheral blood of 27 patients with psoriasis and 13 healthy donors. Serum IL-21 levels were measured by ELISA. The relationship between the levels of TFH cells, IL-21, B cells and disease severity were analysed.
  
  
  RESULTS
  Compared with healthy donors, higher levels of circulating CD3(+) CD4(+) CXCR5(+) cells, CD3(+) CD4(+) CXCR5(+) ICOS(+), CD3(+) CD4(+) CXCR5(+) PD-1(+), CD3(+) CD4(+) CXCR5(+) ICOS(+) PD-1(+) TFH cells and CD19(+) IgD(+) CD27(-) naive B, CD19(+) CD86(+) activated B, but lower levels of CD19(+) IgD(+) CD27(+) preswitch and CD19(+) IgD(-) CD27(+) postswitch memory B cells, were observed in patients with psoriasis. In addition, serum IL-21 levels in patients with psoriasis were significantly higher than those in healthy donors, and showed to be positively correlated with the levels of different subsets of TFH cells, and the level of CD19(+) CD86(+) B cells was also correlated with TFH cells and IL-21 levels. Furthermore, a significant correlation was found between the levels of CD3(+) CD4(+) CXCR5(+) ICOS(+) TFH cells, CD3(+) CD4(+) CXCR5(+) ICOS(+) PD-1(+) TFH cells, CD19(+) CD86(+) B cells and IL-21 with Psoriasis Area and Severity Index scores.
  
  
  CONCLUSIONS
  The levels of TFH cells and activated B cells were increased in the peripheral blood of patients with psoriasis, and positively correlated with disease severity. These results suggest that TFH cells and activated B cells may play a role in the pathogenesis of psoriasis.
authors.affiliation: Department of Dermatology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: J
authors.initials: J
authors.lastname: Niu
authors.affiliation: Department of Dermatology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Song
authors.affiliation: Department of Dermatology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: X
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Dermatology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Zhai
authors.affiliation: Department of Dermatology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: H
authors.initials: H
authors.lastname: Zhong
authors.affiliation: Department of Dermatology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: F
authors.initials: F
authors.lastname: Hao
mesh_terms: D000328:Adult; D001402:B-Lymphocytes / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007111:Immunity, Cellular; D007378:Interleukins / Q000097:blood*; D008213:Lymphocyte Activation / Q000276:immunology*; D018655:Lymphocyte Count; D008297:Male; D011565:Psoriasis / Q000097:blood / Q000175:diagnosis / Q000276:immunology*; D012720:Severity of Illness Index; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D000098546:Interleukin-21
chemical_list: D007378:Interleukins; D000098546:Interleukin-21