title: Prevalence of anti-citrullinated protein antibodies (ACPA) in patients with diffuse large B-cell lymphoma (DLBCL): a case-control study.
abstract: BACKGROUND
  Antibodies against citrullinated proteins (ACPA) have been recognised as the most specific serum marker for rheumatoid arthritis. However, serum autoantibodies such as anti-nuclear antibodies have also been detected in the sera of different lymphatic malignancies without accompanying rheumatologic disease. Therefore, we conducted a study to evaluate the prevalence of ACPA in diffuse large B-cell non-Hodgkin lymphoma (DLBCL).
  
  
  METHODS
  Sera of 395 DLBCL patients and 258 age-matched healthy controls were investigated to evaluate the prevalence of ACPA and RF. ACPA-positive data were stratified into subgroups of RF positivity and established prognostic parameters for DLBCL, including overall survival. In addition, the ACPA serum concentrations levels were compared to an ACPA-positive RA cohort (n = 175). The statistics were performed with χ2 test and Mann- Whitney-U test; Kaplan-Meyer curves (log rank test) were used to analyse the overall survival. P-value <0.05 was statistically significant.
  
  
  RESULTS
  ACPA, but not RF, occurred significantly more frequently in the sera of DLBCL patients than in healthy controls (3.5% versus 0.8%, p = 0.030). However, the ACPA serum concentration levels were significantly lower than in RA patients (median 10.4 versus 124.1 U/ml, p = 0.0001). After subgroup stratification, ACPA positivity in DLBCL was significantly associated with male gender (4.4% versus 0%, p = 0.022; odds ratio 1.046, CI 1.014-1.079) and with RF-IgM seropositivity (1.77% versus 0%, p = 0.043), but not with prognostic parameters for DLBCL.
  
  
  CONCLUSIONS
  DLBCL is associated with a significantly higher prevalence of ACPA, with an increased prevalence in male patients, and simultaneous RF-IgM positivity. However, ACPA is not prognostic for DLBCL. The prevalence of RF-IgM, -IgA, or -IgG did not differ from healthy controls.
authors: Department of Internal Medicine I, José-Carreras-Centre for Immuno- and Gene Therapy, University Medical School of Saarland, Homburg/Saar, Germany.
authors: Gunter
authors: G
authors: Assmann
authors: Department of Internal Medicine, General Hospital of Herrenberg, Esslingen-Herrenberg, Germany.
authors: Klara
authors: K
authors: Shihadeh
authors: Department of Internal Medicine I, José-Carreras-Centre for Immuno- and Gene Therapy, University Medical School of Saarland, Homburg/Saar, Germany.
authors: Viola
authors: V
authors: Poeschel
authors: Department of Internal Medicine I, José-Carreras-Centre for Immuno- and Gene Therapy, University Medical School of Saarland, Homburg/Saar, Germany.
authors: Niels
authors: N
authors: Murawski
authors: Department of Internal Medicine I, José-Carreras-Centre for Immuno- and Gene Therapy, University Medical School of Saarland, Homburg/Saar, Germany.
authors: Jutta
authors: J
authors: Conigliarou
authors: Institute of Medical Biometry, Epidemiology and Medical Informatics, Saarland University, Homburg/Saar, Germany.
authors: Mei Fang
authors: MF
authors: Ong
authors: Department of Internal Medicine I, José-Carreras-Centre for Immuno- and Gene Therapy, University Medical School of Saarland, Homburg/Saar, Germany.
authors: Michael
authors: M
authors: Pfreundschuh
mesh_terms: D001323:Autoantibodies / Q000097:blood*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse / Q000097:blood / Q000276:immunology* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000276:immunology*; D011379:Prognosis; D016036:Seroepidemiologic Studies; D015996:Survival Rate
chemical_list: D001323:Autoantibodies; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide