Salivary Antilectin IgA Antibodies in a Cohort of Children Residing in an Endemic Area of Bangladesh

Abstract

It is now generally accepted that what was earlier known as Entamoeba histolytica actually is comprised of two genetically distinct but morphologically indistinguishable species— Entamoeba histolytica and Entamoeba dispar. The confirmation of these two distinct species of Entamoeba is perhaps the major accomplishment in the field of amebiasis research during the last decade. It is believed that only E. histolytica , sensu stricto , can cause intestinal and extraintestinal disease or produce asymptomatic colonization, while E. dispar cannot invade tissues. The role of antiamebic IgA response in immune defense against E. histolytica infection is not fully understood. A number of studies have reported that antiamebic IgA was present in the saliva of subjects with invasive amebiasis and asymptomatic cyst passers of E. histolytica or E. dispar (1–4). However, it is controversial whether antiamebic salivary IgA response occurs during asymptomatic E. histolytica infection (2,4). The galactoseinhibitable adherence lectin of E. histolytica is a well-characterized protein of E. histolytica. The present work analyzes the IgA antibody response against this amebic lectin in saliva of preschool children in Bangladesh.