- Saliva IgM and IgA are a sensitive indicator of the humoral immune response to Escherichia coli O157 lipopolysaccharide in children with enteropathic hemolytic uremic syndrome. Ludwig, K., Grabhorn, E., Bitzan, M., Bobrowski, C., Kemper, M.J., Sobottka, I., Laufs, R., Karch, H., Müller-Wiefel, D.E. Pediatr. Res. (2002)