Serum Shiga toxin 2 values in patients during acute phase of diarrhoea-associated haemolytic uraemic syndrome

Aim Shiga toxins are delivered via systemic circulation and are considered to be the cause of diarrhoea-associated haemolytic uraemic syndrome (HUS), as they injure endothelial cells, particularly in the glomeruli. This study measured Shiga toxin 2 (Stx2) in the serum of children affected in by HUS due to Stx2 producing Escherichia coli. Methods The concentration of free Stx2 was measured in the serum of 16 children, collected immediately after admission to the clinic in the acute phase of HUS, using a sandwich enzyme-linked immunosorbent assay. The family members of two children were also investigated, with the relative toxicity of Stx2 assessed by a Vero cell-based fluorescent assay. Results Stx2 was found in the serum of eight of the 16 children who were investigated. It was also detected in four of the six family members not showing symptomatic HUS, with an extremely high level in two. Conclusion An absent or rather low concentration of Stx2 was found in the serum of children admitted to the clinic with diarrhoea-associated HUS. The high concentration of Stx2 in family members without HUS, but mostly with watery diarrhoea and raised functional activity, was in line with the concept of early injury by Stx2.