Hemolytic-uremic syndrome and T-cryptantigen exposure by neuraminidase-producing pneumococci: an emerging problem?

Hemolytic anemia, thrombocytopenia, and renal failure form a constellation of complications observed in patients infected with neuraminidase-producing pneumococci. The circulating enzyme causes exposure of the T-cryptantigen on cell surfaces to which most people possess a naturally occurring antibody. Antigen-antibody interaction activates effector systems that lead to the clinical manifestations. The syndrome is most frequently seen in infants, in whom it carries more than a 50% mortality rate. T-cryptantigen activation can be detected by demonstrating red cell agglutination by the peanut lectin Arachis hypogea. Plasma exchange and avoidance of blood products containing immunoglobins are of value in the management of this devastating complication of pneumococcal infection.