title: Stroke alters respiratory burst in neutrophils and monocytes.
abstract: OBJECTIVE
  Stroke-induced immune alterations predispose patients to infections. Although the relationship between stroke and the adaptive immune system has been investigated in detail, to date it is unknown whether the innate immune system, which forms the first line of antibacterial defense, is also impaired in patients with stroke. Therefore, we investigated whether chemotaxis, phagocytosis, oxidative burst, degranulation of defensins, and NETosis in monocytes and in neutrophil granulocytes are altered in patients with stroke compared with controls.
  
  
  METHODS
  Sixty-three patients having acute ischemic stroke were recruited within 12 hours of symptom onset; blood was sampled on admission and on days 1, 3, 5, and 7. Thirty-seven age-matched controls were also recruited. Cell migration, phagocytosis, and oxidative burst of phagocytes were determined in vitro. Human neutrophil peptides 1 to 3 and serum metanephrine levels were measured by enzyme-linked immunosorbent assay, and NETosis was quantified by immunohistochemistry.
  
  
  RESULTS
  The key mechanisms required for bacterial killing, oxidative burst, and NETosis were significantly reduced in samples taken from patients with stroke compared with controls, whereas migration, phagocytic function, and defensin production remained unimpaired in monocytes and granulocytes from patients with stroke.
  
  
  CONCLUSIONS
  Stroke-induced immune alterations include impairment of the first-line defense performed by specialized phagocytes against bacteria. The hypothesis that these changes enhance susceptibility to acquired infections is supported by our observation that on admission oxidative burst in monocytes was more impaired in patients with stroke with subsequent stroke-associated infections.
authors: From the Section of Neuroimmunology, Department of Neurology (J.R., K.S., B.G., C.K., A.D., A.V.), Institute of Immunology and Transfusion Medicine (B.B., A.V.), and Diagnostic Radiology and Neuroradiology (S.L.), University Medicine Greifswald, Germany.
authors: Johanna
authors: J
authors: Ruhnau
authors: Karsten
authors: K
authors: Schulze
authors: Bernadette
authors: B
authors: Gaida
authors: Sönke
authors: S
authors: Langner
authors: Christof
authors: C
authors: Kessler
authors: Barbara
authors: B
authors: Bröker
authors: Alexander
authors: A
authors: Dressel
authors: Antje
authors: A
authors: Vogelgesang
mesh_terms: D000109:Acetylcholine / Q000378:metabolism; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015550:Cell Degranulation; D002465:Cell Movement; D002544:Cerebral Infarction / Q000473:pathology; D002634:Chemotaxis, Leukocyte / Q000502:physiology; D023082:Defensins / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006728:Hormones / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology* / Q000502:physiology; D009504:Neutrophils / Q000276:immunology* / Q000502:physiology; D010587:Phagocytosis / Q000502:physiology; D016897:Respiratory Burst / Q000276:immunology* / Q000502:physiology; D020521:Stroke / Q000188:drug therapy / Q000276:immunology*; D015912:Thrombolytic Therapy; D014057:Tomography, X-Ray Computed
chemical_list: D023082:Defensins; D006728:Hormones; D000109:Acetylcholine
keywords: brain ischemia; granulocytes; immunosuppression; infection; phagocytes; respiratory burst; stroke