Immune responses to mosquito saliva in 14 individuals with acute systemic allergic reactions to mosquito bites.
BACKGROUND
Mosquito bite-induced acute systemic allergic reactions are an increasing clinical concern and have not been optimally characterized immunologically.


OBJECTIVE
We wanted to study the immunologic basis of these reactions.


METHODS
Sera were received from 14 individuals with a history of acute systemic allergic reactions to mosquito bites, defined as the presence of one or more of the following: urticaria, angioedema, wheezing, dyspnea, hypotension, and decrease or loss of consciousness. Ten individuals were from the United States and one each was from Canada, Germany, Japan, and Switzerland. An indirect ELISA was developed to measure specific IgE and IgG antibodies to saliva from 5 common mosquito species with different geographic distributions: Aedes aegypti, Aedes vexans, Aedes albopictus, Anopheles sinensis, and Culex quinquefasciatus. Twenty-nine individuals with negative bite test results from laboratory-reared mosquitoes served as control subjects.


RESULTS
Mosquito saliva-specific IgE levels to all 5 species were significantly increased in the individuals with systemic allergic reactions compared with the control subjects ( P < .061 for Aedes vexans and P < .008 for the remaining 4 species). By using the mean of the control subjects plus 1 SD as a cut-off level, 11 individuals had positive results to Aedes albopictus and up to 4 additional species; 3 individuals had positive results to only one species. Saliva-specific IgG levels were not significantly increased in the individuals with systemic allergic reactions compared with levels seen in the control subjects ( P > .05).


CONCLUSIONS
Acute systemic allergic reactions to mosquito bites involve mosquito saliva-specific IgE and can be characterized immunologically. Aedes albopictus is the most common species associated with systemic allergic reactions to mosquito bites.
Peng
Zhikang
Z
Section of Allergy and Clinical immunology, Department of Pediatrics and Child Health, University of Manitoba, 532-714 McDermot Avenue, Winnipeg, Manitoba, Canada R3E 3P4. zpeng@ms.umanitoba.ca
Beckett
Andrew N
AN
Engler
Renata J
RJ
Hoffman
Donald R
DR
Ott
Nancy L
NL
Simons
F Estelle R
FE
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000818:Animals; D002648:Child; D002675:Child, Preschool; D009033:Culicidae / Q000276:immunology*; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology*; D007073:Immunoglobulin E / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007299:Insect Bites and Stings / Q000276:immunology*; D008297:Male; D012463:Saliva / Q000276:immunology*
D007074:Immunoglobulin G; D007073:Immunoglobulin E