Persistence of pneumococcal antibodies after immunization in patients with systemic lupus erythematosus.

: Antibody levels to 12 different pneumococcal capsular polysaccharides as well as the combined mean antibody level were measured in 19 patients with systemic lupus erythematosus (SLE) at 1, 2 and 3 years after immunization with a polyvalent pneumococcal vaccine and compared to 5 normal control subjects immunized at the same time. The mean levels in the 19 SLE patients were lower in all 3 years but the difference reached significance only in Year 1. At 3 years, 8 of the 19 SLE patients had levels below that considered to be protective and one such patient developed a pneumococcal pneumonia.