Abstract
The few studies already published about phagocyte functions in Chediak-Higashi syndrome (CHS) has stated that neutrophils present slow rate of bacterial killing but normally ingest microorganisms. In the present study, both phagocytosis and killing of Staphylococcus aureus were verified to be in neutrophils from two patients with CHS when these functions were simultaneously evaluated by a fluorochrome phagocytosis assay. Electron microscopic examination showed morphologic differences among neutophils from CHS patients and normal neutrophils regarding the cytoplasmic structures and the aspects of the phagolysosomes. It was noteworthy the presence of giant phagolysosomes enclosing bacteria in active proliferation commonly observed in CHS neutrophils after 45 min of phagocytosis, wich corresponded with the impaired bactericidal activity of these leukocytes. The present results suggest that phagocytosis may also be defective in CHS, and point out to the sensitivity of the fluorochrome phagocytosis assay and its application in clinical laboratories.
neutrophils; Chediak; Higashi syndrome; phagocytosis; bacterial killing
Delayed phagocytosis and bacterial killing in Chediak-Higashi syndrome neutrophils detected by a fluorochrome assay: ultrastructural aspects
Raquel Bellinati-Pires
Maristela M. Salgado1
Paulo P. Joazeiro2
Magda M. S. Carneiro-Sampaio3
Instituto Adolfo Lutz, Seção de Imunologia, São Paulo, Brasil
Instituto Adolfo Lutz, Seção de Microscopia Eletrônica, São Paulo, Brasil
Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Imunologia, São Paulo, Brasil
The few studies already published about phagocyte functions in Chediak-Higashi syndrome (CHS) has stated that neutrophils present slow rate of bacterial killing but normally ingest microorganisms. In the present study, both phagocytosis and killing of Staphylococcus aureus were verified to be in neutrophils from two patients with CHS when these functions were simultaneously evaluated by a fluorochrome phagocytosis assay. Electron microscopic examination showed morphologic differences among neutophils from CHS patients and normal neutrophils regarding the cytoplasmic structures and the aspects of the phagolysosomes. It was noteworthy the presence of giant phagolysosomes enclosing bacteria in active proliferation commonly observed in CHS neutrophils after 45 min of phagocytosis, wich corresponded with the impaired bactericidal activity of these leukocytes. The present results suggest that phagocytosis may also be defective in CHS, and point out to the sensitivity of the fluorochrome phagocytosis assay and its application in clinical laboratories.
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Publication Dates
-
Publication in this collection
04 June 2009 -
Date of issue
Dec 1992
