title: Systemic cytokine levels and the effects of etanercept in TNF receptor-associated periodic syndrome (TRAPS) involving a C33Y mutation in TNFRSF1A.
abstract: OBJECTIVE
  To investigate the levels of the pro-inflammatory cytokines IL-6, TNF-alpha, IL-1beta, IL-8, IL-10 and IL-12p70 in the plasma of patients with TNF receptor-associated periodic syndrome (TRAPS) in relation to CRP levels and treatment with etanercept.
  
  
  METHODS
  Cytokine concentrations were measured in sequential plasma samples obtained from eight patients with a C33Y mutation in TNFRSF1A and diagnosed with TRAPS, using cytokine bead array. The TRAPS samples were compared with samples from normal controls and rheumatoid arthritis patients.
  
  
  RESULTS
  Levels of IL-6 were significantly elevated in C33Y TRAPS patients and these correlated with CRP levels in some of the patients. IL-8 levels were also significantly elevated in the TRAPS patients. However, neither TNF-alpha nor IL-1beta demonstrated a similar increase. This differed from the patients with rheumatoid arthritis, for whom levels of IL-6, IL-8, TNF-alpha, IL-1beta and IL-10 were significantly elevated. The levels of detectable TNF-alpha in the TRAPS patients' plasma were elevated during etanercept treatment.
  
  
  CONCLUSIONS
  The cytokine profile of C33Y TRAPS differs from that of a typical autoimmune inflammatory condition such as rheumatoid arthritis, as only IL-6 and IL-8 were elevated in C33Y TRAPS patients, as distinct from a generalized elevation of pro-inflammatory cytokines. However, only some of the C33Y patients tested showed a relationship between elevated IL-6 and CRP. This is consistent with clinical observations that there is marked heterogeneity between individuals with TRAPS, including those in the same family cohort. Although etanercept has a therapeutic effect in some TRAPS patients, it induces increased plasma concentrations of TNF-alpha, possibly by increasing TNF-alpha stability.
authors.affiliation: Division of Immunology, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK.
authors.forename: M L
authors.initials: ML
authors.lastname: Nowlan
authors.forename: E
authors.initials: E
authors.lastname: Drewe
authors.forename: H
authors.initials: H
authors.lastname: Bulsara
authors.forename: N
authors.initials: N
authors.lastname: Esposito
authors.forename: R A
authors.initials: RA
authors.lastname: Robins
authors.forename: P J
authors.initials: PJ
authors.lastname: Tighe
authors.forename: R J
authors.initials: RJ
authors.lastname: Powell
authors.forename: I
authors.initials: I
authors.lastname: Todd
mesh_terms: D000328:Adult; D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D002097:C-Reactive Protein / Q000378:metabolism; D016207:Cytokines / Q000097:blood*; D000068800:Etanercept; D010505:Familial Mediterranean Fever / Q000188:drug therapy / Q000235:genetics*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D018124:Receptors, Tumor Necrosis Factor / Q000627:therapeutic use*; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000235:genetics*; D013577:Syndrome
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D016207:Cytokines; D007074:Immunoglobulin G; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D002097:C-Reactive Protein; D000068800:Etanercept