Impaired antibody levels to tetanus toxoid and pneumococcal polysaccharides in acute leukemias.

Antibody levels to the protein antigen tetanus toxoid (TTx) and the carbohydrate antigens pneumococcal capsular polysaccharides (PCP) were studied by enzyme immunoassay in 14 patients with acute lymphocytic leukemia (ALL) and 32 patients with acute non lymphocytic leukemia (ANLL) before and three weeks after initiation of chemotherapy. The antibody levels to TTx were significantly lower in ALL patients than in controls. This was associated with elevated levels of sCD8 (soluble CD8) in the serum of 12 out of the 14 ALL patients. Patients with ANLL had normal antibody levels before chemotherapy. After chemotherapy ANLL patients with septic complications had a reduced increase of antibody titers to TTx than patients without sepsis. The average antibody titers to PCP decreased in patients with sepsis, while they increased slightly in patients without sepsis. We conclude that in contrast to ANLL patients ALL patients have preexisting decreased antibody levels to thymus dependent protein antigens, while antibody levels to thymus independent carbohydrate antigens are normal in both types of leukemias.