title: Seasonal Association of Immune Thrombocytopenia in Adults.
abstract: BACKGROUND
  Immune thrombocytopenia (ITP) is an autoimmune disorder. It is characterized by thrombocytopenia due to thrombocyte destruction mediated by autoantibodies; however, cytotoxic and defective regulatory T-lymphocytes play an important role in its pathogenesis. While childhood ITP is usually acute, self-limiting and generally seasonal in nature, ITP in adults is usually chronic; its relation with seasons has not been studied.
  
  
  OBJECTIVE
  We investigated whether months and/or seasons have triggering roles in adults with ITP.
  
  
  METHODS
  Descriptive study.
  
  
  METHODS
  A retrospective case review of adult patients with primary ITP diagnosed at various University Hospitals in cities where Mediterranean climate is seen was performed. Demographic data, date of referral and treatments were recorded. Corticosteroid-resistant, chronic and refractory cases were determined. Relation between sex, corticosteroid-resistant, chronic and refractory ITP with the seasons was also investigated.
  
  
  RESULTS
  The study included 165 patients (124 female, mean age=42.8±16.6). Most cases of primary ITP were diagnosed in the spring (p=0.015). Rates of patients diagnosed according to the seasons were as follows: 35.8% in spring, 23% in summer, 20.6% in fall, and 20.6% in winter. With respect to months, the majority of cases occurred in May (18.2%). Time of diagnosis according to the seasons did not differ between genders (p=0.699). First-line treatment was corticosteroids in 97.3%, but 35% of the cases were corticosteroid-resistant. Steroid-resistant patients were mostly diagnosed in the spring (52.1%) (p=0.001). ITP was chronic in 52.7% of the patients and they were also diagnosed mostly in the spring (62.7%) (p=0.149).
  
  
  CONCLUSIONS
  This is the first study showing seasonal association of ITP in adults and we have observed that ITP in adults is mostly diagnosed in the spring. The reason why more patients are diagnosed in the spring may be due to the existence of atmospheric pollens reaching maximum levels in the spring in places where a Mediterranean climate is seen.
authors.affiliation: Department of Hematology, Mersin University Faculty of Medicine, Mersin, Turkey.
authors.forename: Anıl
authors.initials: A
authors.lastname: Tombak
authors.affiliation: Department of Internal Medicine, Mersin University Faculty of Medicine, Mersin, Turkey.
authors.forename: Burcu
authors.initials: B
authors.lastname: Boztepe
authors.affiliation: Department of Hematology, Mersin University Faculty of Medicine, Mersin, Turkey.
authors.forename: Naci
authors.initials: N
authors.lastname: Tiftik
authors.affiliation: Department of Hematology, Ege University Faculty of Medicine, İzmir, Turkey.
authors.forename: Melda
authors.initials: M
authors.lastname: Cömert
authors.affiliation: Department of Hematology, Akdeniz University Faculty of Medicine, Antalya, Turkey.
authors.forename: Ozan
authors.initials: O
authors.lastname: Salim
authors.affiliation: Department of Internal Medicine, Çukurova University Faculty of Medicine, Adana, Turkey.
authors.forename: Kaniye
authors.initials: K
authors.lastname: Aydın
authors.affiliation: Department of Hematology, Çukurova University Faculty of Medicine, Adana, Turkey.
authors.forename: Emel
authors.initials: E
authors.lastname: Gürkan
authors.affiliation: Department of Hematology, Akdeniz University Faculty of Medicine, Antalya, Turkey.
authors.forename: Orhan Kemal
authors.initials: OK
authors.lastname: Yücel
authors.affiliation: Department of Hematology, Ege University Faculty of Medicine, İzmir, Turkey.
authors.forename: Güray
authors.initials: G
authors.lastname: Saydam
authors.affiliation: Department of Biostatistics, Düzce University Faculty of Medicine, Düzce, Turkey.
authors.forename: Mehmet Ali
authors.initials: MA
authors.lastname: Sungur
keywords: Allergens; immune thrombocytopenia; pollen; seasons