Skin test reactivity and Der p-induced interleukin 10 production in patients with asthma or rhinitis infected with Ascaris.
BACKGROUND
Helminth infections have been associated with reduced reactivity to aeroallergens, which could be related to interleukin 10 (IL-10) production, as reported in schistosomiasis.


OBJECTIVE
To compare skin responses to aeroallergens with Der p specific IL-10 production in patients with asthma or rhinitis according to Ascaris infection status.


METHODS
Cross-sectional study of 113 patients with asthma or rhinitis from a region endemic for geohelminths. Stool examinations and skin prick tests to aeroallergens were performed in all the patients. Der p specific IL-10 production was measured in the supernatant of peripheral blood mononuclear cell (PBMC) cultures of a subsample of 53 patients.


RESULTS
Forty-seven patients had Ascaris in their stool samples. Skin test results were positive in 77% of Ascaris-infected patients and in 71% of uninfected individuals. Median levels of Der p specific IL- 10 in PBMC cultures of infected and uninfected patients were similar (7.8 and 8.4 pg/mL, respectively). The lack of association remained when parasite load was taken into account and when patients with evidence of previous infection were removed from the uninfected group.


CONCLUSIONS
In patients with asthma or rhinitis living in an urban area endemic for geohelminths, we found no association between Ascaris infection and skin reactivity to aeroallergens. Furthermore, there was no difference in Der p specific IL-10 production by PBMCs. These negative findings indicate that different from what is observed in Schistosoma infection, Ascaris lumbricoides infection in individuals living in an urban area does not induce strong regulatory responses.
Ponte
Eduardo Vieira
EV
Respiratory Disease Center, University Hospital Professor Edgard Santos, Salvador, Brazil. evponte@yahoo.com.br
Lima
Fabiana
F
Araújo
Maria Ilma
MI
Oliveira
Ricardo Riccio
RR
Cardoso
Luciana Santos
LS
Cruz
Alvaro Augusto
AA
D000293:Adolescent; D000328:Adult; D000485:Allergens; D000818:Animals; D039741:Antigens, Dermatophagoides / Q000276:immunology*; D001196:Ascariasis / Q000453:epidemiology / Q000276:immunology*; D017164:Ascaris lumbricoides / Q000276:immunology; D001249:Asthma / Q000276:immunology / Q000382:microbiology*; D003430:Cross-Sectional Studies; D004785:Environmental Pollutants; D005260:Female; D006801:Humans; D016753:Interleukin-10 / Q000276:immunology / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism; D008297:Male; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology / Q000382:microbiology*; D012882:Skin Tests
D000485:Allergens; D039741:Antigens, Dermatophagoides; D004785:Environmental Pollutants; D016753:Interleukin-10