The American Society for Clinical Investigation Inc.
Abstract
The antigen-specific immune unresponsiveness seen in bancroftian
filariasis was studied by examining lymphokine production
in peripheral blood mononuclear cells (PBMC) or PBMC subpopulations
from 10 patients with asymptomatic microfilaremia,
13 patients with elephantiasis and 6 normal North Americans.
In each group of patients, the kinetics of the lymphokine response
and the response to mitogens and nonparasite antigens
did not differ significantly. In marked contrast, when antigeninduced
lymphokine production was examined, most patients with
microfilaremia were unable to produce either interleukin 2 (IL-
2) or y-interferon (i.e., were nonresponders), and the few who
could (hyporesponders, generally with quite low microfilaremia
levels) did so at levels significantly less than those of patients
with elephantiasis, all of whom showed strong responses to parasite
antigen. Removal of neither adherent cells or T8+ cells
affected the parasite-specific anergy seen in those with microfilaremia,
suggesting a state of T cell tolerance to the parasite in
patients with this most common clinical manifestation of bancroftian
filariasis