title: Lack of specificity of anticyclic citrullinated peptide antibodies in advanced human immunodeficiency virus infection.
abstract: OBJECTIVE
  To determine the prevalence and specificity of anticyclic citrullinated peptide antibodies (anti-CCP) and rheumatoid factor (RF) for rheumatoid arthritis (RA) in human immunodeficiency virus (HIV) infection and to evaluate the effect of immune reconstitution on these markers.
  
  
  METHODS
  Patients with advanced HIV infection without arthritis were enrolled. CD4+ T lymphocyte counts (CD4), anti-CCP, and RF were determined before initiating antiretroviral therapy (ART) and repeated after 6 months. Results were compared to those of healthy controls. Patients were followed for the development of RA for 1 year.
  
  
  RESULTS
  Sixty patients and 26 controls were studied. Six-month followup results were available on 49 patients. Mean (SD) levels of anti-CCP were higher in patients with HIV compared to controls: respectively, 9.50 (11.41) versus 0.80 (1.32) units (p < 0.001). Mean (SD) levels decreased to 4.85 (8.12) units (p = 0.006) after 6 months of ART (HIV-infected group). Fifteen percent of patients initially tested positive for anti-CCP, 4% after 6 months versus no controls (p = 0.031). Forty-seven percent of patients initially tested positive for RF, 18% after 6 months versus 8% of controls (p < 0.001). Decreases in RF and anti-CCP after ART were accompanied by increased mean (SD) CD4: from 129 (56) to 278 (140) cells/mm(3) (p < 0.001). Anti-CCP and RF positivity was not associated with the development of RA.
  
  
  CONCLUSIONS
  Increased titers of anti-CCP and RF occur in advanced HIV infection. Although more specific than RF, before immune reconstitution, anti-CCP is an unreliable diagnostic marker for RA and does not necessarily predict future RA. After immune reconstitution, the specificity of anti-CCP approaches that of a control group.
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, PO Box 19063, Tygerberg Campus, Francie van Zijl Avenue, Bellville 7505, South Africa. rdutoit@sun.ac.za
authors.forename: Riëtte
authors.initials: R
authors.lastname: du Toit
authors.forename: David
authors.initials: D
authors.lastname: Whitelaw
authors.forename: Jantjie J
authors.initials: JJ
authors.lastname: Taljaard
authors.forename: Lisa
authors.initials: L
authors.lastname: du Plessis
authors.forename: Monika
authors.initials: M
authors.lastname: Esser
mesh_terms: D000328:Adult; D000906:Antibodies / Q000097:blood / Q000276:immunology*; D000918:Antibody Specificity / Q000276:immunology*; D023241:Antiretroviral Therapy, Highly Active; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D015704:CD4 Antigens / Q000097:blood; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000150:complications / Q000188:drug therapy / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000276:immunology*; D015995:Prevalence; D012213:Rheumatic Fever / Q000097:blood / Q000209:etiology / Q000276:immunology; D012217:Rheumatoid Factor / Q000097:blood; D013019:South Africa / Q000453:epidemiology
chemical_list: D000906:Antibodies; D015415:Biomarkers; D015704:CD4 Antigens; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D002097:C-Reactive Protein; D012217:Rheumatoid Factor