Serum antibody response to pneumococcal vaccine in children with nephrotic syndrome.

Children with nephrotic syndrome are susceptible to serious pneumococcal disease and may be immunodeficient on the basis of abnormal humoral immune responses to natural antigens or immunoglobulin loss during relapse. As part of an ongoing study to evaluate pneumococcal anticapsular antibody concentration and immunologic competence, 27 steroid-responsive and six steroid-resistant patients with nephrotic syndrome, and 12 age-matched control subjects, were vaccinated with polyvalent pneumococcal vaccine. Antibody responders were defined as patients with at least a twofold increase in antibody after vaccination as well as an antibody concentration greater than 200 ng of anticapsular antibody nitrogen per milliliter (ngN/ml) after vaccination. Pneumococcal antibody concentrations before and after vaccination were significantly depressed in steroid-resistant patients when compared with control subjects (P less than .002) and with the steroid-responsive nephrotic syndrome group (P less then .001). Steroid-responsive nephrotic children who were not receiving corticosteroid therapy at the time of vaccination had significantly higher antibody concentrations to five pneumococcal types before vaccination and to seven types after vaccination compared with control subjects (P less than .05). Fewer steroid-responsive patients receiving corticosteroids achieved antibody concentrations greater than or equal to 200 ngN/ml against type 19F compared with patients not receiving steroids or with control subjects (P less than .05). These results suggest that pneumococcal vaccine is immunogenic in children with steroid-responsive nephrotic syndrome and may protect these patients from disease due to pneumococcal types contained in the vaccine.