Immunoglobulin classes and persistence of anti-pneumococcal antibodies in splenectomized adults and adolescents after pneumococcal vaccination.

The IgG-, IgM- and IgA- anti-pneumococcal antibody response to pneumococcal vaccination in 29 splenectomized adults and adolescents with hereditary spherocytosis or previous traumatic splenic rupture was determined by an enzyme-linked immunosorbent assay. It was not significantly different from that of 12 healthy controls except for a lower IgM class antibody increase in the splenectomized against one of four antigens studied. The antibody response was predominantly of IgG class, but significant increases in IgM and IgA class antibodies against all four antigens (polysaccharide types 2, 6A, 12F and 14) studied were observed. In 1/29 splenectomized and 2/12 healthy individuals (7%) the IgG antibody class did not predominate. In 36 adults and adolescents splenectomized due to traumatic rupture or during surgery for gastric ulcer, 77% of the peak geometric mean total antibody concentration four weeks after vaccination was still present after 21 months (16-26 months).