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Defects in granulocyte function in various chromosome abnormalities (Down's-, Edwards'-, Cri-du-chat syndrome)
Insights
Infants with certain genetic disorders may have impaired granulocyte function, leading to recurrent infections despite normal immune system components. This study investigated specific defects in immune cell activity in infants with autosomal aberrations.
Area of Science:
- Immunology
- Genetics
- Pediatrics
Background:
- Infants with autosomal aberrations often exhibit recurrent infections.
- Humoral and cellular immune mechanisms may appear intact despite susceptibility to infections.
Purpose of the Study:
- To evaluate granulocyte functions in infants with autosomal aberrations and recurrent infections.
- To identify specific immune defects contributing to diminished resistance to infection.
Main Methods:
- Assessed granulocyte functions including chemotaxis, phagocytosis, intracellular killing, and metabolism.
- Tested phagocytosis of Candida albicans and killing of Staphylococcus aureus and Escherichia coli.
- Measured serum opsonin levels (IgG, IgM, CH50, C3).
Main Results:
- Serum-dependent or cell-dependent phagocytosis defects of Candida albicans were observed in infants with cat-cry syndrome and trisomy 18.
- One infant showed additional serum-dependent defects in killing Candida albicans and Staphylococcus aureus.
- An infant with trisomy 21 exhibited chemotaxis defects and reduced cellular killing of Staphylococcus aureus and Escherichia coli.
Conclusions:
- Specific granulocyte functional defects can occur in infants with autosomal aberrations, contributing to recurrent infections.
- These defects may manifest as impaired phagocytosis or intracellular killing, even with normal opsonin levels.
- Identifying these immune dysfunctions is crucial for understanding infection susceptibility in these infants.
Abstract:
In five infants with autosomal aberrations and diminished resistance to infection (in spite of intact humoral and cellular immune mechanisms) several granulocyte functions (chemotaxis, phagocytosis, intracellular killing and metabolism of killing) were measured. A serum-dependent or a cell-dependent disturbance of phagocytosis of Candida albicans was found in two infants with cat-cry syndrome and one with trisomy 18. In one of these children there was an additional serum dependent defect of the killing of Candida albicans and of Staphylococcus aureus, serum levels of opsonins (IgG, IgM, CH50 and C3) being within normal range. An infant with trisomy 21 showed, in addition to a cellular defect of chemotaxis, a reduced cellular ability of the killing of Staphylococcus aureus and of Escherichia coli in autologous and AB-pool-serum. Phagocytosis of these bacteria remained normal.