Haemolytic anaemia in association with Escherichia coli O157 infection in two sisters.

Two sisters, 2 and 5 years of age, suffered from acute haemolytic anaemia occurring after gastroenteritis with Escherichia coli O157. One patient developed clinical signs of severe and acute intravascular haemolysis and sepsis. She received transfusion and antibiotic therapy. The second patient presented with mild to moderate haemolytic symptoms only. None of them developed renal impairment. In serum of both children, elevated titres of short-lived agglutinins were demonstrated in the indirect haemagglutination assay consisting of sheep erythrocytes coated with lipopolysaccharide from E. coli O157. By immunoblot analysis IgM antibodies against the O157 lipopolysaccharide were demonstrated in the acute phase sera but not in follow up sera taken 2 months after disease. On erythrocyte membranes, adsorption of microbial antigens was detected by use of a pool-immunoglobulin fluorescence test. The immunological status of both patients was normal. Complete recovery from haemolytic disease was observed without further therapy. Microbial antigens attached to the cell surface were assumed to be the pathophysiological cause of E. coli O157 associated haemolytic anaemia in two siblings.