Histopathological changes and the distributions of T and B lymphocytes and
IgG producing plasma cells were recorded in the abomasum and abomasal lymph
nodes of goats 3, 7 and 21 weeks post-infection (wpi) after an experimenta
l infection with H. contortus. The low rate of worm recovery by 3 wpi (5.6%
) might have been due to larvae death as suggested by the presence of granu
lomas in the abomasal mucosa at 3 and 7 wpi, or simply due to a poor larval
establishment. Marked increase in the secretion of mucus by mucous cells t
ogether with an abundant infiltration of eosinophils, mast cells, CD3(+) T
lymphocytes, CD79a(+) B cells, IgG(+) plasma cells and globule leukocytes w
ere recorded in the abomasal mucosa, especially at 7 wpi. Except for the gl
obule leukocytes, this reaction decreased substantially by week 21, suggest
ing this cell type may have been involved in rejection of adult nematodes.
The abomasal lymph nodes showed marked hyperplasia, particularly of CD79a() B cells and IgG(+) plasma cells in all infected goats. These reactions ma
y have been responsible for the reduction in the number of worms found in t
he abomasum between 3 and 7 wpi.