title: In vitro interferon γ improves the oxidative burst activity of neutrophils in patients with chronic granulomatous disease with a subtype of gp91phox deficiency.
abstract: OBJECTIVE
  Chronic granulomatous disease (CGD) is a genetically heterogeneous primary immunodeficiency caused by a defect in phagocyte production of oxygen metabolites, and resulting in infections produced by catalase-positive microorganisms and fungi. Interferon γ (IFN-γ) has a multitude of effects on the immune system. Although preliminary studies with CGD patients on treatment with IFN-γ showed that it enhanced phagocytosis and superoxide production, ongoing studies did not reveal a significant increase of this function. Here we investigated the oxidative capacity of phagocytes in different subtypes of CGD patients on treatment with IFN-γ in vitro.
  
  
  METHODS
  Fifty-seven patients with CGD from 14 immunology centres were enrolled to our multi-centre study. Twenty-one patients were studied as controls. Oxidative burst assay with dihydrorhodamine 123 (DHR) was used and the stimulation index (SI) was calculated with respect to CGD subtypes in both neutrophils and monocytes before, and then one and 24 hours after adding IFN-γ.
  
  
  RESULTS
  Upon comparison of the SIs of the patients' neutrophils before in vitro IFN-γ at hour 0, and after adding IFN-γ at hour 1 and 24 were compared, and the differences were determined between hours 0-24 and hours 1-24. This difference was especially apparent between hours 1-24. In CGD subtypes, particularly in gp91phox subtype, it was seen that, following in vitro IFN-γ, SIs of neutrophils began to increase after hour 1, and that increase became more apparent at hour 24.
  
  
  CONCLUSIONS
  Our study showed that IFN-γ treatment may increase the oxidative bursting activity by increasing the superoxide production in neutrophils, particularly in gp91phox subtype.
authors.affiliation: Department of Paediatric Allergy and Immunology, Antalya Research and Training Hospital, Antalya, Turkey.
authors.forename: Serkan
authors.initials: S
authors.lastname: Filiz
authors.affiliation: Department of Paediatric Allergy and Immunology, Akdeniz University, Antalya, Turkey.
authors.forename: Dilara F Kocacik
authors.initials: DF
authors.lastname: Uygun
authors.affiliation: Department of Microbiology and Immunology, Akdeniz University, Antalya, Turkey.
authors.forename: Sadi
authors.initials: S
authors.lastname: Köksoy
authors.affiliation: Department of Microbiology and Immunology, Akdeniz University, Antalya, Turkey.
authors.forename: Emel
authors.initials: E
authors.lastname: Şahin
authors.affiliation: Department of Paediatric Allergy and Immunology, Akdeniz University, Antalya, Turkey.
authors.forename: Olcay
authors.initials: O
authors.lastname: Yeğin
keywords: chronic granulomatous disease; interferon γ; monocytes; neutrophils