Does activation of the FcgammaRIIa play a role in the pathogenesis of the acute lung injury/acute respiratory distress syndrome?
Clin Sci (Lond)
; 118(8): 519-26, 2010 Jan 26.
Article
em En
| MEDLINE
| ID: mdl-20088831
ABSTRACT
ALI (acute lung injury) and its more severe form ARDS (acute respiratory distress syndrome) are inflammatory diseases of the lung characterized by hypoxaemia and diffuse bilateral infiltrates. Disruption of epithelial integrity and injury to endothelium are contributing factors of the development of ALI/ARDS, and alveolar damage is the most pronounced feature of ALI/ARDS. The resulting increase in lung microvascular permeability promotes influx of inflammatory cells to the alveolar spaces. Oedema fluid contains pro-nflammatory mediators and plasma proteins, including Igs (immunoglobulins). Moreover, several reports describe the presence of autoantibodies and immune complexes [anti-IL-8 (interleukin-8) autoantibody/IL-8 complexes] in lung fluids (oedema and bronchoalveolar lavage fluids) from patients with ALI/ARDS. These immune complexes associate with FcgammaRIIa (Fcgamma IIa receptor) in lungs of patients with ARDS. Furthermore, the expression of FcgammaRIIa is substantially elevated in lungs of these patients. FcgammaRIIa appears on virtually all myeloid cells, platelets and endothelial cells. It is a low-affinity receptor for IgG that preferentially binds aggregated immunoglobulins and immune complexes. FcgammaRs regulate phagocytosis and cell-mediated cytotoxicity, and initiate the release of inflammatory mediators. It should be noted that immune complexes formed between either anti-neutrophil autoantibodies and their specific antigens or anti-HLA (human leucocyte antigen) antibodies and target antigens are implicated in the pathogenesis of TRALI (transfusion-related acute lung injury), and importantly, animal studies indicate that FcgammaRs are essential for these complexes to cause damage to the lungs. Therefore, we hypothesize that FcgammaRs such as FcgammaRIIa could contribute to the pathogenesis of ALI/ARDS.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Síndrome do Desconforto Respiratório
/
Receptores de IgG
/
Lesão Pulmonar Aguda
Tipo de estudo:
Etiology_studies
/
Prognostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Clin Sci (Lond)
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Estados Unidos