Background: The diagnosis of allergic reactions to drugs is difficult. Most
skin tests are not standardized, and in vitro tests are needed to avoid pr
ovocation tests. Cross-linking of IgE on basophils is known to cause the re
lease of both cysteinyl leukotriene (Cys-LT) and histamine. We aimed to eva
luate the diagnostic utility (sensitivity, specificity, and efficiency) of
measurement of sulfoleukotrienes in drug allergy.
Methods: We performed a prospective study in 55 patients with proven immedi
ate adverse reactions to drugs (30 to beta -lactams, six to acetaminophen,
and 19 to aspirin) and 64 drug-exposed nonallergic controls. Positive diagn
osis was established by history, skin tests, and, if needed, oral provocati
on tests. Cys-LT release was determined after drug-allergen stimulation by
the cellular antigen stimulation test (CAST(R)) technique. Histamine releas
e was also assessed on the same samples by enzyme immunoassay. Spontaneous
and anti-Fc epsilon RI alpha -induced mediator release was also studied in
all subjects. Sensitivity, specificity, and efficiency were calculated.
Results: Net Cys-LT release was over the maximal threshold given by the man
ufacturer in 19/55 patients and in 9/64 controls. Net histamine release was
over 5% of total histamine content in 28/55 patients and 34/64 controls. T
he efficiency of both tests was low.
Conclusions: Thus, in most cases, the in vitro Cys-LT test has little or no
diagnostic utility and is not superior to histamine release.