The association of giardiasis with reduced intestinal secretory immunoglobulin A

Immune Response to Giardia duodenalis

“…On the other hand, mechanisms of innate immunity may protect the parasite from destruction. For example, mucus has been reported to protect the trophozoites from being killed by lipolytic products present in the intestinal fluid (205).…”

“…In fact, there are contradictory observations about the possible association of depressed secretory IgA and Giardia infection. Zinneman and Kaplan (205) reported that hypogammaglobulinemic patients with giardiasis had a decreased number of secretory IgA antiGiardia-specific antibodies and that their infection was mild. In malnourished patients, an enhancement of giardiasis was reported (42).…”

Isotype Defects

“…128,129 Presumably the lack of secretory IgA permits the attachment to and proliferation of these protozoa on the intestinal epithelium. 130,131 If giardiasis occurs in sIgAD, malabsorption resulting from flattened villi, often accompanied by nodular lymphoid hyperplasia, may develop. Diagnosis warrants multiple stool analyses and an examination of the duodenal fluid.…”

IgA Deficiency and Other Immunodeficiencies Causing Mucosal Immunity Dysfunction

“…It is presumed that the lack of secretory IgA permits the attachment and proliferation of Giardia lamblia on the intestinal epithelium (Zinneman and Kaplan, 1972).…”