Hydatid cyst or cystic echinococcosis (CE) is a metacestode of dog Echinococcus granulosus a
worldwide zoonotic disease. The study evaluated parasite interaction between patient and CE using
25 cysts of Egyptian patients before therapeutic interventions. These cysts were divided in two
groups: G1: fertile with protoscoleces and G2: non-fertile (sterile) without protoscoleces. Patients'
body reaction differed due to type of CE; fertile one stimulated the local immune defense mechanism
in form of granulomatous immune reactions and significant immune cell infiltration. Histologically,
this led to increase in the adventitial layers thickness with thick fibrous tissue as compared to
non-fertile, and guarded against the hydatidosis sustainability. Besides, fertile CE cyst GATA-3
remained dominant keeping the infection in control status. But, if CD-4+ & CD-8+ T-cell numbers
became boosting, CE didn't sustain fertility as shown by using panel of GATA-3, CD-4+, CD-8+
antibodies that represented Th2, Th subset, and cytotoxic T cells.