title: Evaluation of rheumatoid factor and anti-citrullinated peptide antibodies in relation to rheumatological manifestations in patients with leprosy from Southern Brazil.
abstract: BACKGROUND
  Leprosy patients may present several osteoarticular complaints, which require further evaluation of inflammatory diseases, such as rheumatoid arthritis (RA). Therefore, an adequate clinical assessment in addition to testing for rheumatoid factors (RF) and anticyclic citrullinated peptide antibodies (anti-CCP), can be useful in order to establish the correct diagnosis.
  
  
  METHODS
  In this study, the relation of RF and anti-CCP with rheumatological manifestations was evaluated in 97 leprosy patients from Southern Brazil. The results were compared to RA patients and healthy controls from the same geographical area and ethnic background.
  
  
  RESULTS
  Neuropathy was observed in 71.1% and arthritis in 35.1% of the leprosy patients. A high frequency of RF positivity was observed among the leprosy patients (41.2%, 40/97), with RF immunoglobulin A (IgA) significantly associated with arthritis (OR = 7.9, 95% CI = 1.5-40.6 P = 0.008). Anti-CCP was observed in 9.3% (9/97) of the patients, with anti-CCP2 being the most frequent subtype. Only 4.1% (4/97) of the patients were RF and anti-CCP concomitantly positive. RF IgM showed a significant association with leprosy when compared to healthy controls (P < 0.0001) whereas for anti-CCP2 no significant results were observed (P = 0.0585). However, both biomarkers showed a strong association with RA when compared to leprosy in patients from the same geographical area and ethnic background (anti-CCP2 OR = 38.6; 95% CI = 16.49-90.26; P < 0.0001 and RF IgM OR = 4.51; 95% CI = 2.62-7.77; P < 0.0001).
  
  
  CONCLUSIONS
  Due to the similarity of some rheumatological manifestations in leprosy with other inflammatory diseases, such as RA, clinical and laboratorial evaluation of affected patients must be carefully assessed in order to achieve proper diagnosis and treatment.
authors.affiliation: Laboratório de Imunopatologia, Departamento de Patologia Médica, Clinical Hospital of Federal University of Parana, Curitiba, Brazil.
authors.forename: Carla Fontoura
authors.initials: CF
authors.lastname: Dionello
authors.affiliation: Laboratório de Imunopatologia, Departamento de Patologia Médica, Clinical Hospital of Federal University of Parana, Curitiba, Brazil.
authors.forename: Shirley Ramos
authors.initials: SR
authors.lastname: Rosa Utiyama
authors.affiliation: Departamento de Medicina Interna, Clinical Hospital of Federal University of Parana, Curitiba, Brazil.
authors.forename: Sebastião Cézar
authors.initials: SC
authors.lastname: Radominski
authors.affiliation: Setor de Dermatologia, Centro Regional de Especialidades Metropolitano de Curitiba, Curitiba, Brazil.
authors.forename: Ewalda
authors.initials: E
authors.lastname: Stahlke
authors.affiliation: Laboratório de Imunopatologia, Departamento de Patologia Médica, Clinical Hospital of Federal University of Parana, Curitiba, Brazil.
authors.forename: Servio Tulio
authors.initials: ST
authors.lastname: Stinghen
authors.affiliation: Laboratório de Imunopatologia, Departamento de Patologia Médica, Clinical Hospital of Federal University of Parana, Curitiba, Brazil. iara.reason@hc.ufpr.br.
authors.forename: Iara Jose
authors.initials: IJ
authors.lastname: de Messias-Reason
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000175:diagnosis / Q000208:ethnology / Q000276:immunology*; D015415:Biomarkers / Q000097:blood; D001938:Brazil / Q000453:epidemiology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood*; D007918:Leprosy / Q000097:blood / Q000175:diagnosis / Q000208:ethnology / Q000276:immunology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010456:Peptides, Cyclic / Q000276:immunology*; D011237:Predictive Value of Tests; D012217:Rheumatoid Factor / Q000097:blood*; D012307:Risk Factors; D055815:Young Adult
chemical_list: D015415:Biomarkers; D007075:Immunoglobulin M; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D012217:Rheumatoid Factor
keywords: anti-CCP antibodies; leprosy; rheumatoid arthritis; rheumatoid factor; rheumatological manifestations