Quantitative histological and immunohistochemical findings in jejunal biopsy specimens in giardiasis.

Jejunal mucosa biopsies from non-immune deficient patients with Giardia lamblia infestation were examined and showed three different groups of mucosal changes, distinguishable on morphological and immunohistochemical grounds. In three patients no morphological or immunohistochemical abnormalities were found (group A). In five patients a normal villous architecture was seen. These biopsies had increased numbers of interepithelial lymphocytes and of immunoglobulin containing cells in the lamina propria, with a relative increase of the number of IgA and IgG containing cells (group B). Two patients with a malabsorption syndrome due to giardiasis had marked villous atrophy, documented by morphometric measurements and large numbers of interepithelial lymphocytes and of immunoglobulin containing cells in the lamina propria, especially IgA and IgG (group C). These findings differ considerably from those in patients with immunodeficiency or gluten sensitive enteropathy. This suggests that when villous atrophy of the jejunal mucosa is found immunohistochemistry of jejunal biopsy specimens may be helpful in the differential diagnosis between mere giardiasis and giardiasis superimposed on immunodeficiency or gluten sensitive enteropathy.