DEPENDENCE OF EOSINOPHIL GRANULOCYTE INFILTRATION INTO NODULES ON THEPRESENCE OF MICROFILARIAE PRODUCING ONCHOCERCA-VOLVULUS

Onchocercomata with a single live or dead worm were analyzed to elucid ate the infiltration of eosinophils. Females were classified according to the presence or absence of microfilariae in their uteri and in the nodular tissues. Immunohistochemical staining was performed using ant ibodies against eosinophil cationic protein, peroxidase, and major bas ic protein. Very few eosinophils were detected in nodules containing f emales without microfilariae or male or dead worms only, whereas eosin ophils were abundant in all nodules with females producing microfilari ae. The occurrence of eosinophils was not related to the age of the wo rm. Occasionally, degenerated or dead microfilariae attacked by activa ted eosinophils were found. By examination of onchocercomata with or w ithout microfilariae from the same patient, it was excluded that the o ccurrence of eosinophils was dependent mainly on the host's immune sta tus. In conclusion, live adult Onchocerca volvulus do not elicit an in vasion of eosinophils as long as they do not produce microfilariae. Th e absence of eosinophilia does not exclude onchocerciasis.