Antibodies to Shiga toxin in the serum of children with Shigella-associated haemolytic uraemic syndrome

Antibodies to Shiga toxin (Stx) were measured in the sera of 49 children wi th Shigella dysenteriae serotype 1 infection, of whom 17 had haemolytic ura emic syndrome (HUS) and 32 had no complications (uncomplicated shigellosis, UCS), Children with HUS had lower levels of total IgG and IgM and lower Ig M titres to Stx than those with UCS, The number of children with neutralisi ng antibodies was similar in the two groups. Of the children with HUS, 11 h ad HUS on enrolment and six developed HUS subsequent to enrolment, Antibody titres in children who subsequently developed HUS were compared with those in children with UCS to assess whether differences in antibody titres occu rred before the development of HUS, IgA titres to Stx were found to be high er in children who subsequently developed HUS than in those with UCS, Howev er, logistic regression analysis revealed that titres of Stx antibodies in the serum were not significant risk factors for the development of HUS, Thu s, although the levels of Stx antibodies were different in children with HU S, and higher IgA titres to Stx were identifiable in children who subsequen tly developed HUS compared,vith those with UCS, the relevance of these find ings in the development of HUS remains to be elucidated.