The histology and ultrastructure of the Meyers-Kouwenaar body in ferrets infected with Brugia malayi.

A study was made of the Meyers-Kouwenaar (MK) body in the livers of experimentally infected ferrets. Meyers-Kouwenaar bodies, the carcasses of microfilariae (mff) covered by deposits of Splendore-Hoeppli (SH) material, were found in small abscesses of eosinophils and in granulomas. The SH deposits varied from an eosinophilic, hyaline fringe around intact mff to multilayered deposits surrounding an unrecognizable granular remnant. In abscesses, peroxidase activity was intense in SH deposits and the surrounding eosinophils. The presence and localization of IgG were variable in MK bodies, as detected by an enzyme-linked immunohistologic assay; and antigens of mff were not detected in the SH deposits. Electron microscopy of the MK body demonstrated a layered, radial deposition of amorphous and granular material on the mff and a structural heterogeneity which apparently included leukocyte granules and other cell organelles. Leukocytes surrounding MK bodies in abscesses were often degranulated and degenerate; incorporation of lysosomes of eosinophils and cellular debris into the SH deposits at the periphery of the MK bodies was indicated.