title: Persistence of Staphylococcus aureus colonization among individuals with immune-mediated inflammatory diseases treated with TNF-α inhibitor therapy.
abstract: OBJECTIVE
  We investigated the relationship between Staphylococcus aureus colonization and the use of immunosuppressive therapies in patients with immune-mediated inflammatory diseases (IMIDs).
  
  
  METHODS
  We prospectively enrolled IMID patients from the rheumatology and dermatology departments of Oregon Health & Science University. At enrolment, we surveyed patients for S. aureus infection risk factors and those using immune-modulating therapies, and evaluated their colonization status with bilateral nares and inguinal fold cultures. Patients were asked to follow up 6-12 months later for reassessment of colonization status by repeat culture. S. aureus isolates were tested for the presence of methicillin resistance by PCR.
  
  
  RESULTS
  We enrolled a total of 548 IMID patients. At enrolment, 219 (40.0%) patients were colonized with S. aureus, of which 27 (12.3%) were methicillin-resistant S. aureus (MRSA). Baseline colonization rates were similar between TNF-α inhibitor users and non-users (40.5% and 39.4%, P = 0.79), but were significantly higher for psoriasis patients compared with those with RA (43.5% and 31.8%, P = 0.02). A total of 384 patients were available for follow-up. Patients who were colonized at enrolment were more likely to be colonized at follow-up if they were treated with TNF-α inhibitors during the study as compared to patients without TNF-α inhibitor exposure [odds ratio (OR) = 2.2 (95% CI 1.1, 4.2), P = 0.02].
  
  
  CONCLUSIONS
  Patients with psoriasis are more likely to be colonized with S. aureus than patients with RA. Patients who are colonized with S. aureus are more likely to remain colonized if exposed to TNF-α inhibitors.
authors.affiliation: Oregon Health & Science University, 3375 SW Terwilliger Blvd, Portland, OR 97239, USA. winthrop@ohsu.edu.
authors.forename: Cara D
authors.initials: CD
authors.lastname: Varley
authors.forename: Atul A
authors.initials: AA
authors.lastname: Deodhar
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Ehst
authors.forename: Antony
authors.initials: A
authors.lastname: Bakke
authors.forename: Andrew
authors.initials: A
authors.lastname: Blauvelt
authors.forename: Robert
authors.initials: R
authors.lastname: Vega
authors.forename: Shellie
authors.initials: S
authors.lastname: Yamashita
authors.forename: Kevin L
authors.initials: KL
authors.lastname: Winthrop
mesh_terms: D000069594:Abatacept; D000068879:Adalimumab; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000009:adverse effects / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized / Q000009:adverse effects / Q000627:therapeutic use; D058846:Antibodies, Monoclonal, Murine-Derived / Q000009:adverse effects / Q000627:therapeutic use; D000068800:Etanercept; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D018796:Immunoconjugates / Q000009:adverse effects / Q000627:therapeutic use; D007074:Immunoglobulin G / Q000009:adverse effects / Q000627:therapeutic use; D007166:Immunosuppressive Agents / Q000009:adverse effects / Q000627:therapeutic use*; D000069285:Infliximab; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D008875:Middle Aged; D015999:Multivariate Analysis; D015995:Prevalence; D011446:Prospective Studies; D011565:Psoriasis / Q000150:complications / Q000188:drug therapy*; D018124:Receptors, Tumor Necrosis Factor / Q000627:therapeutic use; D012213:Rheumatic Fever / Q000188:drug therapy*; D012307:Risk Factors; D000069283:Rituximab; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000209:etiology; D013211:Staphylococcus aureus / Q000302:isolation & purification*; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors; D055815:Young Adult
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D058846:Antibodies, Monoclonal, Murine-Derived; D018796:Immunoconjugates; D007074:Immunoglobulin G; D007166:Immunosuppressive Agents; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha; D000069283:Rituximab; D000069594:Abatacept; D000069285:Infliximab; D000068879:Adalimumab; D000068800:Etanercept
keywords: Staphylococcus aureus; biologic therapy; psoriasis; rheumatoid arthritis; tumour necrosis factor-alpha