Streptococcus pneumoniae - Opsonophagocytosis test for functional antibodies against Streptococcus pneumoniae vaccine serotypes.
This test uses suspensions of Streptococcus pneumoniae (13 serotypes) which are confronted with dilutions of the immunoglobulin product. After appropriate incubation is added complement to be activated in the event of substantial antibodies in the immunoglobulin product. After the exposure for the chosen time, they are added to differentiated phagocytic cells, which carry out ingestion (phagocytosis) of pneumococci if they were opsonized by antibody and complement by the existing receptors for "Fc" of antibodies and activated complement fractions, leading to intracellular killing of the pneumococci. The test dilution of the immunoglobulin product, which kills 50% of pneumococci existing in the suspension used is determined (opsonophagocytic titer).