title: Löfgren's syndrome: human leukocyte antigen strongly influences the disease course.
abstract: BACKGROUND
  Sarcoidosis may consist of a number of distinct disease entities, one of which could be Löfgren's syndrome. Patients with Löfgren's syndrome have an acute onset of erythema nodosum (EN) and/or periarticular inflammation or arthritis of the ankles, with bilateral hilar lymphadenopathy (and in some cases parenchymal infiltrates) and usually fever. There is a known association between HLA-DRB1*03 and Löfgren's syndrome.
  
  
  OBJECTIVE
  To investigate whether human leukocyte antigen type influences clinical manifestations, including the disease course in Löfgren's syndrome.
  
  
  METHODS
  We clinically characterized and HLA-DRB1 typed 301 patients with Löfgren's syndrome. A total of 275 of the patients were followed for more than 2 years and classified as having a nonresolving or a resolving disease.
  
  
  RESULTS
  Almost every DRB1*03-positive patient had a resolving disease within 2 years, and 49% of the DRB1*03-negative patients developed a nonresolving disease. Mucosal granulomas were identified significantly more often in DRB1*03-negative patients. Among DRB1*03-negative patients who were treated with oral steroids at disease onset, 80% developed a nonresolving disease.
  
  
  CONCLUSIONS
  Patients with Löfgren's syndrome have a different disease course depending on whether they are DRB1*03 positive or not. This observation has clinical implications, and by comparing DRB1*03-positive and DRB1*03-negative patients with Löfgren's syndrome, we can search for additional markers of importance for developing a resolving or a nonresolving disease, respectively.
authors.affiliation: Department of Medicine, Division of Respiratory Medicine, Lung Research Laboratory L4:01, Karolinska Hospital, S-171 76 Stockholm, Sweden. johan.grunewald@ki.se
authors.forename: Johan
authors.initials: J
authors.lastname: Grunewald
authors.forename: Anders
authors.initials: A
authors.lastname: Eklund
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D018450:Disease Progression; D005260:Female; D005434:Flow Cytometry; D005500:Follow-Up Studies; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006684:HLA-DR Antigens / Q000097:blood* / Q000235:genetics*; D059811:HLA-DRB1 Chains; D006801:Humans; D008297:Male; D008875:Middle Aged; D012507:Sarcoidosis / Q000235:genetics / Q000276:immunology*; D013577:Syndrome; D055815:Young Adult
chemical_list: D015415:Biomarkers; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains