Fulminant meningococcemia in a child with hereditary deficiency of the seventh component of complement and proteinuria

Bacterial meningitis in children. Selected aspects

Accumulating clinical experience has gradually outlined the epidemiology of acute bacterial meningitis, including the epidemic and the sporadic forms, the customary clinical signs related to different age groups and causative organisms, and methods of rapid diagnosis by laboratory examinations. Effective treatment, which continues to evolve, emerged in the 1940s with the development of antibacterial antimicrobials, first with the sulfonamides and then with the penicillins. The literature relative to these aspects of the disease has been abundant in the past few years. This article is directed to a variety of topics that have direct bearing on the disorder but are less often addressed to those who deal with infants and children.

Inherited deficiency of the seventh component of complement: studies of C7-consuming activity

Neither the hemolytic activity nor the protein level of the seventh component of serum complement (C7) was detectable in an 8-year-old girl with nephritis, but in her parents and her brother, they were about half of the normal level. The patient was a homozygote type with a complete deficiency of C7 while her parents and brother were all heterozygote type with a partial deficiency of C7. C7-consuming activity was demonstrated in the native serum of the patient with complete C7 deficiency, and it was found that large amounts of C56 were readily generated upon incubation of the patient's serum with zymosan. It is proposed that the C7-consuming activity in the native serum of this patient is due to small amounts of C56 generated during the activation of serum complement by some kind of infection such as a common cold.

Inherited deficiency of the seventh component of complement associated with meningococcal meningitis: lack of serum bactericidal activity against Neisseria meningitidis in a girl with C7 deficiency and HLA studies of a C7-deficient Japanese family

An 8-year-old girl with meningococcal meningitis lacked serum complement activity. The seventh component of complement (C7) could not be detected in her serum by either functional or immunochemical analysis. The levels of the other components were within the normal range. Her serum complement activity was restored by the addition of purified C7. Her fresh serum showed a total absence of bactericidal activity against Neisseria meningitidis, group Y, but her serum bactericidal activity was restored by the addition of purified C7. The restoration of her serum bactericidal activity was completely inhibited in the presence of Mg2+ EGTA. These findings suggest that restoration of the bactericidal activity of her serum against N. meningitidis might be mediated by the specific antibody against N. meningitidis and the reconstituted complement system in her serum. Heterozygous deficiency of C7 was found in 10 of her family members. Genetic studies showed that the mode of inheritance might be an autosomal codominant trait. No genetic linkage between deficiency of C7 and the HLA system was found.