[Neuraminidase induced hemolytic anemia. Experimental and clinical observations (author's transl)].

Recently, increasing attention has been focussed on the in vivo action of neuraminidase as possible pathogenetical factor of hemolytic anemia and even hemolytic-uremic syndrome. Neuraminidase action in red cell membranes results in the release of neuraminic acid, and thereby the uncovering of previously hidden receptors, socalled cryptantigens. With special reference to the phythemagglutinin Anti-TAh from the peanut (Arachis hypogae) and the agglutinin Anti-AHP from the albumin gland of the small Helix pomatia we describe some new methods for the detection of these cryptantigens. In addition to the screebubg genagglutination test with Anti-TAh we developed an "Anti-T-consumption test" for quantitative detection of neuraminidase action on red cells. With the purified reagents we developed an indirect fluorescnet antibody method on blood smears for the detection of cryptantigens on single cells. By animal experiments we could show that not only the membranes of red cells but the intima of renal capillaries as well are damaged by neuraminidase. With these new methods we observed 14 patients suffering from hemolytic anemia due to bacterial or viral neuraminidase. Some of these patients developed a hemolytic-uremic syndrome. We believe that the positive reaction with Anti-T Ah should lead to prophylactic heparinization to prevent dissiminated intravascular coagulation. Neuraminidase is the first identified toxin which directly acts on the membranes of red cells and the intima of renal capillaries as well, and thereby in some patients may induce hemolytic-uremic syndrome. Possibly, these results may stimulate the development of further testsystems for the detection of still unknown toxins which are not tested with our reagents, but may equally be involved in the damage of cell membranes.