title: A low prevalance of purified protein derivative test positivity in Turkish patients with rheumatoid arthritis. Association with clinical features and HRCT findings.
abstract: OBJECTIVE
  In this study, we aimed to evaluate the frequency of purified protein derivative (PPD) skin test positivity and associated clinical features in RA patients.
  
  
  METHODS
  We included 94 (80 F, 14 M, mean age: 55.8) consecutive RA patients with a disease duration of 8.7 years. PPD test was performed in all RA patients; clinical features were recorded down; chest x-ray, pulmonary function tests and HRCT were available in all cases. As the control group, we included data of 21 SLE, 44 AS, 27 OA, 16 gouty arthritis and 18 vasculitis patients.
  
  
  RESULTS
  The frequencies of PPD positivity in RA (29.8%) and SLE (19%) patients were lower than in patients with AS (65.9%), gouty arthritis (68.8%) and OA (63%) (all p values < 0.01). PPD-positive RA patients were more frequently smokers (p = 0.005) and had a higher rate of RF seropositivity (p = 0.04) than PPD-negatives. PPD was less frequently positive in erosive RA disease (p = 0.033). Chest x-rays and HRCT abnormalities were detected in 41.8% and 62.7% of RA patients, respectively. Frequencies of chest x-ray and HRCT abnormalities in PPD-positive and PPD-negative patients were not different from each other (p > 0.05).
  
  
  CONCLUSIONS
  In our country in which tuberculosis is relatively frequent -contrary to the situation in AS patients- we observed a lower frequency of PPD positivity in RA and SLE patients compared to patients with other rheumatic diseases. We did not find any relationship between PPD positivity and the frequency of chest x-ray, HRCT abnormalities.
authors.affiliation: Department of Internal Medicine, Trakya Medical Faculty, University of Trakya, Edirne, Turkey.
authors.forename: I H
authors.initials: IH
authors.lastname: Köker
authors.forename: O N
authors.initials: ON
authors.lastname: Pamuk
authors.forename: C
authors.initials: C
authors.lastname: Karlikaya
authors.forename: N
authors.initials: N
authors.lastname: Tunçbilek
authors.forename: N
authors.initials: N
authors.lastname: Cakir
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000276:immunology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013902:Radiography, Thoracic; D012129:Respiratory Function Tests; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D014374:Tuberculin Test; D014397:Tuberculosis, Pulmonary / Q000150:complications / Q000000981:diagnostic imaging* / Q000276:immunology*; D014421:Turkey