Acute tropical
pulmonary eosinophilia (TPE) is characterized by
wheezing, pulmonary infiltrates, marked peripheral blood
eosinophilia, and very high serum levels of filaria-specific
antibodies. To evaluate the amount and character of the filaria-specific
antibodies in the lungs in this disorder, bronchoalveolar lavage was carried out in individuals with acute TPE, in normal subjects, and in patients with
elephantiasis or
asthma. Striking elevations of total
IgE were found in the lower respiratory tract epithelial lining fluid (ELF) of patients with TPE along with high levels of filarial-specific
IgG,
IgM, and
IgE. When patients with acute TPE were treated with
diethylcarbamazine and evaluated again 6-14 d later, there was marked reduction in ELF parasite-specific
IgG and
IgE, which paralleled a rapid clinical response. Immunoblot comparison of the
antigen recognition patterns of ELF and serum
antibodies demonstrated a general similarity in parasite
antigens recognized, but the lung
IgE and
IgG antibodies appeared to recognize only a certain subset of the parasite
antigens recognized by serum
antibodies. Thus, a profound antibody response to filarial
infection is found in the lungs of patients with TPE, suggesting that these filaria-specific
antibodies play an important role in the pathogenesis of this disorder.