The ætiology of the disease syndrome in wuchereria bancrofti infections

Immunopathology of lymphatic filariasis in man

“…It was clear that the marked lymphatic inflammation observed in these patients was being caused both by reactions to dying parasites as previously described [15] and by responses to living adult worms of both sexes. In addition to gross changes in the lymphatics such as endothelial thickening and development of varicosities, inflammation which appeared to result from release or secretion of material from the parasite developed around the worms, bringing with it infiltration of eosinophils, plasma cells, lymphocytes, and macrophages.…”

“…The parasites first cause a dilatation of the lymphatic followed by hypertrophy of the vessel wall. There is an endothelial and connective tissue proliferation with polypoid growths protruding into the lumen, but so long as the worm remains alive, the vessel appears to remain patent [15]. This patency, however, does not assure normal lymphatic function as lymphographic studies document clearly the development of a characteristic tortuosity of the lymph vessels with loss of valvular function and backflow of lymph during this pre-obliterative phase [2].…”

“…It is uncertain what causes adult, worms to die, but their deaths are associated with certain distinctive pathologic changes [15]: An area of necrosis develops about the parasite, resulting both from degeneration of inflammatory cells and dissolution of parasite material. A granulomatous reaction ensues, with the formation of foreign body giant cells and a concomitant infiltration of plasma cells and eosinophils.…”