IgE responses in human filariasis. I. Quantitation of filaria-specific IgE.
We have developed a noncompetitive solid phase radioimmunoassay to quantitate human IgE antibodies against soluble adult antigens of Brugia malayi (B.m.), a filarial parasite, in sera of patients with various forms of clinical filariasis in Madras, India. A single reference serum was shown to contain 23 micrograms/ml of B.m.-specific IgE by depletion analysis and was used as a standard serum throughout the study. The levels of specific IgE ranged in the patients sera from 2 to 23,000 ng/ml. When these individuals were divided into clinical groups, the individuals with tropical pulmonary eosinophilia had the highest levels (mean = 8630 ng/ml) and were significantly higher than all the other groups (p less than 0.001). The lowest levels were seen in patients with circulating microfilariae (mean = 30.5 ng/ml). Patients exhibiting lymphatic obstruction (i.e., chronic pathology group) had levels slightly higher than microfilaremics (mean = 68 ng/ml) but were not significantly different (p less than 0.1). Surprisingly, individuals living in endemic areas but who had no clinical signs of filariasis also showed appreciable levels of B.m.-specific IgE (mean = 55 ng/ml). The B.m.-specific IgE represented 0.1 to 48% of the total IgE. High percentages of specific IgE may be responsible for evoking allergic symptomatology in patients with tropical pulmonary eosinophilia.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000918:Antibody Specificity; D000941:Antigens; D001666:Binding Sites, Antibody; D002009:Brugia / Q000276:immunology*; D005260:Female; D005368:Filariasis / Q000276:immunology*; D005370:Filarioidea / Q000276:immunology*; D006801:Humans; D007106:Immune Sera / Q000494:pharmacology; D007073:Immunoglobulin E / Q000096:biosynthesis*; D008297:Male; D008875:Middle Aged; D011852:Radioallergosorbent Test
D000941:Antigens; D007106:Immune Sera; D007073:Immunoglobulin E