Trichuris trichiura elicits a secretory response in infected children - abstract

ABSTRACT

Trichuriasis occurs in children infected with the tropical helminth Trichuris trichiura. The children usually present with various clinical symptoms such as diarrhoea, stunting, and finger clubbing along with anaemia. An investigation was carried out to determine the mechanism of the watery diarrhoea observed during infection which ceased upon expulsion of the worms. A hypothesis was proposed that the diarrhoea observed during the period of infection occurred as a result of the net secretion of chloride ions across the epithelium. This active secretion of chloride ions could be a consequence of the immunologically specific IgE antibody medicated response to antigens secreted by the helminth shown in previous studies. A preliminary determination of the concentration of the chloride ions in the stools of the infected children before and after treatment revealed a higher concentration of chloride ions in the stools collected before treatment. Rectal biopsies were clamped at zero voltage in Ussing chambers and challenged on the mucosal side with antigen derived from Trichuris trichiura. The short-circuit current, a measure of ion movement, was monitored. The specific chloride channel blocker, anthracene-9-carboxylic acid, and furosemide, a chloride pump blocker, were used to demonstrate that the secretory response to antigen was chloride ion mediated. The antihistamine, diphenhydramine hydrochloride, was used to demonstrate that histamine released from degranulating mast cells played an important role in the response. The viability of the biopsies was checked at the end of each experiment by challenging on the serosal side with acetylcholine chloride (AU)