Antibacterial polysaccharide antibody deficiency after allogeneic bone marrow transplantation.

Allogeneic bone marrow-engrafted adults immunized with meningococcal types A and C and pneumococcal type 14 polysaccharide antigens showed only low antibody titers of the IgM class, no antibody titers of the IgG or IgA classes, and no bactericidal activity in vitro. The analytical isoelectrofocusing showed the appearance of a restricted pattern of clonotypes in a minority of subjects. These observations are consistent with the hypothesis that B cells in bone marrow transplant patients express some characteristics of neonatal B cells and suggest that polysaccharide-protein conjugates, rather than isolated polysaccharide, might be utilized in the setting of bone marrow transplantation.