Related Experiment Videos
Defective opsonization. A common immunity deficiency
Insights
A defect in serum opsonization impairs phagocytosis in children with frequent infections. This immune defect, possibly inherited, can be corrected by normal plasma, suggesting a missing factor.
Area of Science:
- Immunology
- Genetics
Background:
- Frequent infections in children can stem from underlying immune system deficiencies.
- Serum opsonization is a critical process for phagocytosis, enhancing the engulfment of pathogens by immune cells.
Purpose of the Study:
- To investigate a defect in serum opsonization for phagocytosis in children experiencing recurrent infections.
- To explore the inheritance pattern and potential mechanisms of this immune defect.
Main Methods:
- Assessed serum opsonization and yeast phagocytosis in children with frequent infections and their families.
- Compared defect incidence in affected children versus healthy adults and children with other diseases.
- Investigated the effect of normal plasma on defective serum function in vitro and in vivo.
Main Results:
- Eleven of 43 children with frequent infections exhibited defective serum opsonization for phagocytosis.
- A similar defect was observed in mothers, suggesting dominant inheritance.
- The defective function was correctable by normal plasma, indicating a deficiency rather than an inhibitor.
Conclusions:
- A primary defect in serum opsonization is implicated in unexplained frequent infections in some children.
- The defect appears to be inherited, likely through an unusual dominant pattern.
- The findings suggest a specific missing factor in the serum responsible for impaired phagocytosis.
Abstract:
Serum opsonization of yeasts for phagocytosis by normal polymorphonuclear leucocytes was defective in 11 of 43 children with unexplained frequent infections. The children had a range of infections, largely bacterial, and only 3 had diarrhoea and rash in infancy. A similar defect in at least 6 of the 9 mothers of these children (of either sex), with normal function in the fathers, suggests that the defect was primary and was transmitted by an unusual form of dominant inheritance. Four of 72 healthy adults and 1 of 11 children with unrelated disease showed similar defective function, but the incidence of the defect in the patients with frequent infection was significantly greater than this. The defective function can be corrected, in vitro and in vivo, by normal plasma at concentrations too low to be effective alone. This suggests that there is a defective factor rather than an inhibitor, and that different factors are limiting in normal and in defective plasma. Sera from affected members of the same family do not correct each other, but defective sera from different families usually do.