title: Seasonality of the onset of symptoms, tuberculin test anergy and Kveim positive reaction in a large cohort of patients with sarcoidosis.
abstract: OBJECTIVE
  Sarcoidosis is a systemic granulomatous disease of unknown aetiology and pathogenesis. This study evaluated the seasonal variation in the onset of symptoms, Tuberculin anergy and Kveim positive reaction in a cohort of 492 patients with sarcoidosis and in a subgroup of 248 patients with known Kveim test responses.
  
  
  METHODS
  The medical records of 492 patients with sarcoidosis were retrospectively reviewed. Roger's test for cyclic variation was used to assess the statistical significance of the observed seasonal variation.
  
  
  RESULTS
  For all sarcoidosis patients (n = 492) the onset of symptoms was most frequent in spring (61.8%) and least frequent in summer (31.7%) (P < 0.001). For patients with Tuberculin anergy (n = 364) the onset of symptoms was most frequent in spring and least frequent in autumn (P < 0.001); there was no seasonal variation among Tuberculin positive patients (n = 128). Of those patients with a Kveim test result (n = 248), the onset of symptoms was most frequent in spring and least frequent in summer (P < 0.001); there was no seasonal variation for patients with a negative Kveim results (n = 50 patients).
  
  
  CONCLUSIONS
  The onset of the symptoms was most frequent in spring and least frequent in the second half of the year (summer or autumn) in patients with sarcoidosis, Tuberculin anergy and a positive Kveim reaction. The significance of this finding in relation to aetiology and clinical utility needs to be further assessed.
authors.affiliation: Division of Lung Diseases, Department of Internal Medicine, Cerrahpasa Medical School, Istanbul University, Istnbul, Turkey. sevtap_sipahi@yahoo.com
authors.forename: Sevtap Sipahi
authors.initials: SS
authors.lastname: Demirkok
authors.forename: Metin
authors.initials: M
authors.lastname: Basaranoglu
authors.forename: Elif
authors.initials: E
authors.lastname: Coker
authors.forename: Tuncer
authors.initials: T
authors.lastname: Karayel
mesh_terms: D006801:Humans; D007731:Kveim Test; D012189:Retrospective Studies; D017565:Sarcoidosis, Pulmonary / Q000175:diagnosis / Q000453:epidemiology*; D012621:Seasons; D014374:Tuberculin Test; D014421:Turkey / Q000453:epidemiology