Trichuris suis ova therapy for allergic rhinitis: a randomized, double-blind, placebo-controlled clinical trial.
BACKGROUND
Parasitic helminth infections can protect against allergic airway inflammation in experimental models and have been associated with a reduced risk of atopy and a reduced course of asthma in some observational studies. Although no clinical evidence exists to support the use of helminth therapy for allergic disease, the helminth Trichuris suis has demonstrated efficacy in treatment of inflammatory bowel disease.


OBJECTIVE
To determine efficacy of helminth therapy for allergic rhinitis.


METHODS
We conducted a double-blind, placebo-controlled, parallel group trial in which 100 subjects age 18 to 65 years with grass pollen-induced allergic rhinitis were randomly assigned to ingest a total of 8 doses with 2500 live T suis ova or placebo with an interval of 21 days. The primary outcome was a change in mean daily total symptom score for runny, itchy, sneezing nose (maximum change, 9.0) or in percentage of well days during the grass pollen season.


RESULTS
Treatment with T suis ova (N = 49) compared with placebo (N = 47) caused transient diarrhea peaking at day 41 in 33% of participants (placebo, 2%), and increased eosinophil counts (P < .001) and T suis-specific IgE (P < .05), IgG (P < .001), IgG(4) (P < .003), and IgA (P < .001), whereas there was no significant change in symptom scores (0.0; 95% CI, -0.5 to 0.4; P = .87), well days (3%; 95% CI, -9% to 14%; P = .63), total histamine (P = .44), grass-specific IgE (P = .76), or diameter of wheal reaction on skin prick testing with grass (P = .85) or 9 other allergens.


CONCLUSIONS
Repeated treatment with the helminth T suis induced a substantial clinical and immunologic response as evidence of infection, but had no therapeutic effect on allergic rhinitis.
Statens Serum Institut, Department of Epidemiology Research, Artillerivej 5, DK-2300 Copenhagen, Denmark. pbg@ssi.dk
Peter
P
Bager
John
J
Arnved
Steen
S
Rønborg
Jan
J
Wohlfahrt
Lars K
LK
Poulsen
Tine
T
Westergaard
Henning Willads
HW
Petersen
Bjarne
B
Kristensen
Stig
S
Thamsborg
Allan
A
Roepstorff
Christian
C
Kapel
Mads
M
Melbye
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D003718:Denmark; D003888:Desensitization, Immunologic; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D008875:Middle Aged; D010063:Ovum / Q000276:immunology; D006109:Poaceae / Q000276:immunology; D011058:Pollen / Q000276:immunology; D006255:Rhinitis, Allergic, Seasonal / Q000209:etiology / Q000276:immunology / Q000503:physiopathology / Q000628:therapy*; D016896:Treatment Outcome; D014258:Trichuris / Q000254:growth & development / Q000276:immunology; D055815:Young Adult
D000909:Antibodies, Helminth; D007073:Immunoglobulin E