Sensitization to lupine flour: is it clinically relevant?

Lupineus Augustifolius (blue lupine, Australia) is used for human and animal
consumption. Lupine seeds have been part of normal food intake since the
introduction of lupine flour as an ingredient in wheat flour in the 1990s for
its nutritional and food-processing qualities, lupine consumption became more
widespread in Europe. The frequency of allergic reactions to lupine in the
general population is unknown. Allergic reactions to lupine have been
documented. One anaphylactic reaction has been documented. Cross- reactivity to
peanut is most likely. The only method to confirm an IgE mediated food allergy
is to perform a double blind placebo controlled food challenge. (DBPCFC) This
appears to be the "golden standard" to confirm an IgE mediated food allergy.

We found a prevalence of 6% sensitization in patients with a possible food
allergy. The aim of this study is to investigate if sensitization to lupine
flour in atopic patients has clinical relevance. Additionally, we want to
investigate if cross- reactivity is responsible for co- sensitization to
peanut.

From October 2004 till October 2005 we have performed skin prick tests (SPT)
with lupine flour, peanut and soy extracts, in consecutive patients of the
Department of Allergology, with a suspected food allergy. Co-sensitization is
examined and Histamine Equivalent Prick test (HEP) index is calculated.
Complaints after intake of lupine flour containing food, is administered.
A selection will be made of patients with positive sensitization ( HEP > 0.15)
for lupine flour. The patients will be asked to participate in further
investigations. This will comprise a questionnaire, Double Blind Placebo
Controlled Food Challenge (DBPCFC), Radio Allergo Sorbent Tests (RAST), and if
necessary RAST- inhibition tests.

Patients will be asked to undergo DBPCFC. They will intake lupine flour that is
hidden in small cookies. It may be possible that lupine flour is not a part of
the diet of the patient and in that case it may be called an intervention.

The duration of the visit amounts 3 hours on two different days. One sample of
blood will be taken on the first day. Complaints after the intake of lupine
flour will be gathered by a questionnaire.
A systemic adverse reaction during a PCDBFC is rare, because only a minimal
amount af allergen is used in the first provocation. If the patient develops a
reaction, the provocation will be interrupted and a tablet of anti histaminicum
will be administered. When the complaints are disappeared the patient may go
home.
Escape medicatie available, physician nearby.