PNEUMOCOCCAL INFECTIONS AFTER HUMAN BONE-MARROW TRANSPLANTATION

Seven of 26 long-term survivors (>7 months post-transplant) of bone-marrow transplantation developed penicillin-sensitive pneumococcal infections more than 7 months after transplantation. One patient had two infections. Six of eight infections were associated with pneumococcal bacteremia, and Streptococcus pneumoniae type 6A was isolated in three cases. Two infections were fatal. All patients had normal hematopoietic function, and none was receiving immunosuppresssive therapy. The development of pneumococcal was significantly associated with males and with abnormally low or high serum IgG and IgM level but not with graft-versus-host disease. Serum opsonic activity for S. pneumoniae type 6A was decreased in six of the seven patients when compared to normal pooled serum in an in vitro bactericidal assay. Four of the six patients with impaired opsonic activity had low serum antibody levels for S. pneumoniae type 6A capsular polysaccharide, while the other two patients had low serum CH100 complement activity. Bone-marrow transplant recipients have an increased susceptibility to peumococcal infections and should be evaluated for prophylactic penicillin or pneumococcal vaccination.