T-cell reactions to drugs in distinct clinical manifestations of drug allergy.

BACKGROUND

Recent data indicate that T cells play a major role in different forms of drug allergies.

OBJECTIVE

To show that T-cell reactions are involved in various forms of adverse reactions to different kinds of drugs, and that lymphocyte transformation and skin tests may be positive in patients who had distinct clinical manifestations of drug allergies.

METHODS

We collected data of 44 patients with a highly suggestive history for adverse drug reaction who had on subsequent investigations a positive lymphocyte transforrmation test. In 41/44 patients (93%) skin tests with the suspected drugs were performed and in some cases drug-specific IgE-antibodies were determined. All patients were HLA typed.

RESULTS

Clinical manifestations of the drug allergy were heterogeneous, comprising maculopapular and bullous exanthema, erythema exsudativum multiforme, vasculitis, serum sickness, urticaria, as well as involvement of internal organs. Maculopapular exanthemas formed the largest group (54%), followed by reactions more indicative of immediate hypersensitivity (28%), such as urticaria/angioedema. In most cases (63%), beta-lactam antibiotics were found to have caused the allergic reaction. Skin tests for immediate reactions were positive in 6/40 patients (15%) tested, those for late reactions in 24/38 patients (63%) tested.

CONCLUSIONS

Our data provide evidence that drug-specific T cells can be detected in distinct clinical manifestations of drug allergy. A combined approach using a detailed case history, lymphocyte transformation tests, skin tests (immediate and delayed type) appears to be helpful to identifying the incriminated drug.