Anti-Dirofilaria immitis IgE: seroepidemiology and seasonal variation in an exposed human population.

The seroprevalence of seasonal variation of human anti-Dirofilaria immitis IgE levels were studied in an area where specific IgM and IgG had been previously investigated. An antibody capture ELISA assay was used to detect specific IgE. The IgE seroprevalence observed in the whole population was 12.6%. No specific IgE was detected in atopic individuals or in sera from people suffering other helminthiases. The distribution of the IgE anti-D. immitis seroprevalence by age groups did not show differences. Females had significantly higher levels than males. This isotype of immunoglobulin peaks in July, decreasing sharply in October, and persisting at a level similar to that of a non exposed population during the rest of the year. No specific IgE were detected in subjects with pulmonary alterations related to the parasite, suggesting a possible relationship between the clinico-radiological status and the type of immunoglobulin synthesized in subjects infected by D. immitis.