Bactericidal capacity against Neisseria meningitidis of normal human serum and sera with functional deficiencies of the third and eight complement factor.
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.
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*
D003176:Complement C3; D003178:Complement C3 Nephritic Factor; D003185:Complement C8