Giardia lamblia is an extracellular parasite of the small intestine.
Trophozoites display surface antigenic variation mediated by variant-specific surface proteins (VSP).
Both humoral and cellular mechanisms are important for parasite clearance.
IgA and IgM secretions of the host control the infection.
Depletion of CD4+ T cells results in a marked decrease in parasite clearance.
IgA-dependent host defenses are central for eradicating Giardia trophozoites.
IgA binds to the surface of the trophozoite, inhibiting attachment to the intestinal epithelium.
Specific IgA has been detected bound to trophozoite surfaces in human jejunal biopsies and jejunal fluid.
In an immunocompromised patient, prolongation and recrudescence of giardiasis is evident.
Levels of IgG, IgM, and IgA antibodies are depressed in an immunocompromised patient.

Test your knowledge on the immune response to Giardia lamblia, an extracellular parasite that resides in the small intestine. Learn about the importance of humoral and cellular mechanisms, surface antigenic variation, and the role of IgA and CD4+ T cells in parasite clearance. Explore how immunocompromised patients are affected and the impact on antibody levels. Challenge yourself with this quiz and discover more about this fascinating parasite.