title: Bactericidal capacity against Neisseria meningitidis of normal human serum and sera with functional deficiencies of the third and eight complement factor.
abstract: The bactericidal capacity of serum with C3 deficiency secondary to circulating C3 nephritic factor, serum with C8 deficiency and normal human serum were assessed in vitro against Neisseria meningitidis groups A-C. Normal human serum and C8-deficient serum, originating from a 28-year-old male with two episodes of meningococcal meningitis, showed significant bactericidal capacity against meningococci groups A and B. Against group C meningococci the C8-deficient serum revealed significant bactericidal capacity, whereas normal human serum showed no bactericidal effect. Serum with C3 deficiency, obtained from a 16-year-old female with two episodes of meningococaemia, showed no bactericial effect against meningococci groups A-C. Incubation of normal human serum and C8-deficient serum with isolated nephritic factor resulted in C3 depletion and abolished the bactericidal effect.
mesh_terms: D000293:Adolescent; D000328:Adult; D001770:Blood Bactericidal Activity; D003176:Complement C3 / Q000172:deficiency* / Q000276:immunology; D003178:Complement C3 Nephritic Factor / Q000276:immunology; D003185:Complement C8 / Q000172:deficiency*; D005260:Female; D006801:Humans; D008297:Male; D008585:Meningitis, Meningococcal / Q000276:immunology*; D009345:Neisseria meningitidis / Q000276:immunology*
chemical_list: D003176:Complement C3; D003178:Complement C3 Nephritic Factor; D003185:Complement C8