Early development in healthy children of serum opsonins against nonpathogenic Neisseria meningitidis

Abstract

development in healthy children of serum opsonins against nonpathogenic Neisseria meningitidis. APMIS 100: 449454, 1992.In an earlier study, with the use of chemiluminescence (CL) and phagocytic killing, we could show that in the presence of serum from healthy adults polymorphonuclear leukocytes (PMNL) efficiently handle nonpathogenic Neisseria meningitidis strains, in sharp contrast to those associated with clinical disease. The major part of this difference was dependent on serum factors. In the present study 84 serum samples from children 1-3, 4-6, 7-9, and 10-14 years old were studied by the CL technique according to their ability to opsonize meningococci. There was a highly significant difference (p < 0.001) in all four age groups when the CL indexes obtained with the pathogenic meningococci of the serogroups A, B and C were compared with those of the nonpathogenic menigococci: serogroup 29E and nongroupable meningococci. These findings imply that the ability to opsonize so-called nonpathogenic meningococci is developed early in life and may explain why they are only occasionally able to cause disease.

The effects of live Neisseria meningitidis and tumour necrosis factor‐α on neutrophil oxidative burst and β2‐integrin expression

“…It has previously been shown that PMNL react differently when exposed to different serogroups of N. meningitidis. PMNL are stimulated to a higher degree by nonpathogenic than by pathogenic MC strains (7)(8)(9). In the present study it is shown that TNF-a causes a significant increase in the oxidative burst response when added at the same time as live MC to either isolated PMNL or whole blood.…”

“…In other studies, TNF-a was shown to increase the oxidative burst response and enhance killing of pathogens such as Staphylococcus aureus, Haemophilus infruenzae and fungi (4)(5)(6). Previous studies of PMNL-MC interactions using a chemiluminescence method (CL) have shown that the CL response to pathogenic and nonpathogenic serogroups of MC differs (7)(8)(9). The P2-integrin CD 1 1 b/CD18 is located on the surface of leukocytes and has importance for phagocytosis and adhesion (lo), and previous studies have shown that the expression of C D l l b/CD18 is increased when PMNL are stimulated with LPS or TNF-a (5, 11).…”

Different seroprevalences of antibodies against Neisseria meningitidis serogroup A and Haemophilus influenzae type b in Sudanese and Swedish children

“…Serum samples from 124 children 1-14 years of age were collected in 1989-90 at the Department of Pediatric Anaesthesia, St G6rans Hospital, Stockholm, Sweden as described previously [21]. From each child 2-3 ml blood was drawn, the serum collected and stored in aliquots of 1 ml at -70°C before use.…”