Phadiatop testing in assessing predisposition to respiratory tract symptoms of allergic origin in athletes.

OBJECTIVES To validate the use of the Phadiatop test as a predictor of allergy-associated respiratory tract symptoms (RTS) in trail runners. METHODS The incidence of self-reported RTS was documented in 16 runners for 31 days and related to the Phadiatop status and circulating markers of allergic responses (changes in concentrations of serum IgE (sIgE), differential leucocyte counts) at 8 time points before, during and after a 3-day 95 km trail run. RESULTS Twelve (75%) athletes, of whom 7 (58%) were Phadiatoppositive, presented with post-race RTS. A peak sIgE concentration >100 IU/ml accompanied RTS in only 4 (57%) of the symptomatic Phadiatop-positive subjects. There was no significant difference between the eosinophil and basophil concentrations of the positive and negative groups (p>0.05). One Phadiatop-negative subject presented with RTS as well as a peak sIgE concentration >100 IU/ml. CONCLUSION The Phadiatop assay does not accurately predict the development of post-exercise RTS of allergic origin in trail runners.