Opsonic activity of serum in the acute phase of meningitis

The present study was designed to determine the opsonic activity of serum obtained from meningitis patients in the acute stage of their illness. This study was part of a Danish multicentre prospective study on various aspects of meningitis for a 12-month period. The opsonic activity of serum was determined by a phagocytosis and a chemiluminescence assay using human peripheral blood polymorphonuclear leukocytes. The mean chemiluminescence and phagocytosis indices determined in the sera of 58 patients suffering from various forms of bacterial or non-bacterial meningitis did not differ significantly from that of control sera. Although sera of 4 patients with pneumococcal, 3 with meningococcal, and 1 with streptococcal meningitis exhibited lower opsonic activity than the control sera in the chemiluminescence assay, their values in the phagocytosis assay were similar to control value. It is concluded that serum opsonic activity in meningitis patients is normal and similar to that of healthy individuals.