Hemolytic-uremic syndrome associated with neuraminidase-producing microorganisms: treatment by exchange transfusion.

In two infants with pneumonia, Coombs test positive hemolytic anemia and hemolytic uremic syndrome (HUS), exposure of the Thomsen cryptantigen, probably due to the action of circulating neuraminidase, was demonstrated. Reaction between the exposed T-antigen and anti-T agglutinin, normally present in human blood, can lead to difficulties in serological testing and during blood transfusion. The place of exchange transfusions using washed RBC or heparinized whole blood in the management of this subgroup of HUS is discussed.