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.