title: Epstein-Barr virus in bone marrow of rheumatoid arthritis patients predicts response to rituximab treatment.
abstract: OBJECTIVE
  Viruses may contribute to RA. This prompted us to monitor viral load and response to anti-CD20 therapy in RA patients.
  
  
  METHODS
  Blood and bone marrow from 35 RA patients were analysed for CMV, EBV, HSV-1, HSV-2, parvovirus B19 and polyomavirus using real-time PCR before and 3 months after rituximab (RTX) treatment and related to the levels of autoantibodies and B-cell depletion. Clinical response to RTX was defined as decrease in the 28-joint disease activity score (DAS-28) >1.3 at 6 months.
  
  
  RESULTS
  Before RTX treatment, EBV was identified in 15 out of 35 patients (EBV-positive group), of which 4 expressed parvovirus. Parvovirus was further detected in eight patients (parvo-positive group). Twelve patients were negative for the analysed viruses. Following RTX, EBV was cleared, whereas parvovirus was unaffected. Eighteen patients were responders, of which 12 were EBV positive. The decrease in the DAS-28 was significantly higher in EBV-positive group compared with parvo-positive group (P = 0.002) and virus-negative patients (P = 0.04). Most of EBV-negative patients that responded to RTX (75%) required retreatment within the following 11 months compared with only 8% of responding EBV-positive patients. A decrease of RF, Ig-producing cells and CD19(+) B cells was observed following RTX but did not distinguish between viral infections. However, EBV-infected patients had significantly higher levels of Fas-expressing B cells at baseline as compared with EBV-negative groups.
  
  
  CONCLUSIONS
  EBV and parvovirus genomes are frequently found in bone marrow of RA patients. The presence of EBV genome was associated with a better clinical response to RTX. Thus, presence of EBV genome may predict clinical response to RTX.
authors.affiliation: Department of Rheumatology and Inflammation Research, Sahlgrenska University Hospital, Guldhedsgatan 10A, 413 46 Göteborg, Sweden. mattias.magnusson@rheuma.gu.se
authors.forename: Mattias
authors.initials: M
authors.lastname: Magnusson
authors.forename: Mikael
authors.initials: M
authors.lastname: Brisslert
authors.forename: Kiandoht
authors.initials: K
authors.lastname: Zendjanchi
authors.forename: Magnus
authors.initials: M
authors.lastname: Lindh
authors.forename: Maria I
authors.initials: MI
authors.lastname: Bokarewa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D058846:Antibodies, Monoclonal, Murine-Derived / Q000627:therapeutic use*; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000188:drug therapy* / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D001853:Bone Marrow / Q000276:immunology*; D020031:Epstein-Barr Virus Infections / Q000150:complications / Q000188:drug therapy / Q000276:immunology; D005260:Female; D004854:Herpesvirus 4, Human / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D000069283:Rituximab; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D018501:Antirheumatic Agents; D000069283:Rituximab