Serum immune complexes, complement and cerebrospinal fluid immune complex in-patients with bacterial meningitis.

Circulating immune complexes [CIC] were assayed using polyethylene glycol in serum and cerebrospinal fluid of patients with meningococcal meningitis associated with allergic complications. Serum complement [C3] and IgG were measured by radial immunodiffusion technique. All patients had raised CIC in serum and CSF with a lack of correlation between the two sites, which indicated its formation in situ. C3 levels were depressed in all sera which may be due to its consumption in the formation of immune complexes as evident from its significant correlation with serum IC. In conclusion, rise of serum IC may lead to allergic complications and rise of cerebrospinal fluid IC may lead to neurological complications