Penetration of host IgG molecules into hydatid cysts.

Host IgG was detected in 15 out of 18 peritoneal hydatid cysts obtained from experimentally infected gerbils and in 18 out of 61 mouse hydatid cysts which had been implanted into the peritoneal cavity of gerbils for periods ranging from one day to two years. A wide variation in host IgG concentration was observed among the different cysts in which these immunoglobulins were found. These findings are discussed in terms of the possible manner by which macromolecules may enter into the hydatid cysts.