Giant Cell Reaction Against the Laminated Membrane of Echinococcus Cysts in Reindeer Lungs

Abstract

In 23 pairs of lungs from reindeer two to five years of age, two types of hydatid cysts of Echinococcus granulosus were found: typical well-developed cysts and collapsed degenerated cysts.

Collapsed cysts were found in 13 pairs of lungs, well-developed in nine pairs, while both types of cysts were found in one pair of lungs.

A giant cell formation was present in the innermost zone of the surrounding adventitial membrane of both collapsed cysts and well-developed cysts. The giant cell reaction seemed to be induced by and directed against the laminated membrane. In the areas of the cysts where the laminated membrane showed a close contact with the adventitial membrane, the giant cells seemed to be actively engaged in the inflammatory process. On the contrary, in the areas of the cysts where the laminated membrane had lost contact with the adventitial membrane, the giant cells were degenerated or necrotic, and the space between the membranes was filled with necrotic cells. In cases where the laminated membrane had been pronouncedly disintegrated, the giant cells were also necrotic or nonexistent.

The giant cell reaction which was found even in comparatively young fertile cysts suggests that the reindeer variant of E. granulosus, if such exists, is not especially well-adapted to the reindeer as its intermediate host.

Sammanfattning

I 23 lungpar från 2–5 år gamla remar påvisades två typer av hydatidcystor till Echinococcus granulosus: typiska välutvecklade cystor och kollaberade degenererade cystor.

Kollaberade cystor fanns i 13 lungpar, välutvecklade i 9 och båda typerna av cystor i ett lungpar.

En jättecellsreaktion förekom i innersta zonen av den omgivande adventitia membranen såväl i kollaberade som i välutvecklade cystor. Jättecellsreaktionen synes vara inducerad av och riktad mot den lamellerade membranen. I områden där den lamellerade membranen låg i nära kontakt med adventitia membranen syntes jättecellerna vara aktivt engagerade i den inflammatoriska processen. I områden där den lamellerade membranen hade mist kontakten med den omgivande adventitia membranen var däremot jättecellerna degenererade eller nekrotiska och spalten mellan membranen fylld med nekrotiska celler. I de fall där den lamellerade membranen hade blivit höggradigt upplöst var även jättecellerna nekrotiska eller saknades de helt.

Den förekommande jättecellsreaktionen, även mot tämligen unga fertila cystor, talar för att renvarianten av E. granulosus, om en sådan existerar, ej är sårskilt väl adapterad till renen som sin mellanvärd.