title: Evaluation of allergic sensitivity to Acanthamoeba allergen in patients with chronic cough.
abstract: BACKGROUND
  Acanthamoeba and their proteins can elicit severe allergic airway inflammation in experimental mice.
  
  
  OBJECTIVE
  Although Acanthamoeba can induce severe allergic airway inflammation in mice, there is no allergenicity data for humans.
  
  
  METHODS
  We performed a skin-prick test on 65 patients with chronic cough by using 54 previously known allergens and Acanthamoeba excretory-secretory proteins and enzyme-linked immunosorbent assay on 34 patients to evaluate Acanthamoeba-specific serum immunoglobulin (Ig) levels. To detect a novel Acanthamoeba allergen, Western blot analysis was performed on serum from patients who reacted positively to Acanthamoeba or some pollen allergens.
  
  
  RESULTS
  After skin-prick testing, 29 patients (44.6%) showed positive reactions to one or more common aeroallergens. Acanthamoeba allergenicity was evaluated in 4 of 65 subjects (6.1%). An Acanthamoeba-positive reaction was closely related to several pollen allergens, especially willow tree, poplar, elm, oak, velvet grass, and cockroach. Average levels of Acanthamoeba-specific IgG subtypes in patient serum did not differ compared with healthy subjects; however, Acanthamoeba-specific IgE titers of patients were significantly higher than in healthy subjects. IgE antibodies of patients who tested positive in the skin-prick test reacted strongly to the 15 kDa excretory-secretory protein. Moreover, these antigens also reacted with those who tested positive in the skin-prick test to pollens.
  
  
  CONCLUSIONS
  Taken together, our results indicated that some patients with allergy showed a positive response to the skin-prick test and that they also have high IgE serum levels. However, further experimental investigation is warranted because our preliminary findings indicated that Acanthamoeba might be a new allergen in humans.
authors.affiliation: Department of Internal Medicine, Pusan National University College of Medicine, South Korea.
authors.forename: Hye-Kyung
authors.initials: HK
authors.lastname: Park
authors.forename: Mi-Kyung
authors.initials: MK
authors.lastname: Park
authors.forename: Ki Uk
authors.initials: KU
authors.lastname: Kim
authors.forename: Shin Ae
authors.initials: SA
authors.lastname: Kang
authors.forename: Sang Kyun
authors.initials: SK
authors.lastname: Park
authors.forename: Soon Cheol
authors.initials: SC
authors.lastname: Ahn
authors.forename: Dong-Hee
authors.initials: DH
authors.lastname: Kim
authors.forename: Hak Sun
authors.initials: HS
authors.lastname: Yu
mesh_terms: D000048:Acanthamoeba / Q000276:immunology*; D000328:Adult; D000368:Aged; D000485:Allergens / Q000276:immunology*; D000918:Antibody Specificity / Q000276:immunology; D000953:Antigens, Protozoan / Q000276:immunology*; D016022:Case-Control Studies; D002908:Chronic Disease; D003371:Cough / Q000175:diagnosis / Q000276:immunology*; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000175:diagnosis / Q000276:immunology*; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D008297:Male; D008875:Middle Aged; D012882:Skin Tests; D055815:Young Adult
chemical_list: D000485:Allergens; D000953:Antigens, Protozoan; D007074:Immunoglobulin G; D007073:Immunoglobulin E