[The basophil degranulation test in the diagnosis of Hymenoptera sting allergy]

In 98 patients with a suspected immediate type allergy to hymenoptera stings, skin tests (ST) with venom extracts, RAST determinations of venom specific serum IgE antibodies and basophil degranulation tests (BDT) with unwashed leukocytes were performed. BDT is a technically simple in-vitro method for detecting cell fixed IgE without risk for the patient. The specificity of BDT was investigated in a group of 10 controls not allergic to insect stings, of whom 7 were atopics. A good correlation could be demonstrated between BDT and the histamine release test (HRT), which was performed in the Institute for Allergy and Clinical Immunology, Inselspital, Bern. For the detection of a sensitization to insect venoms, ST with venom extracts were the most sensitive, followed by RAST and BDT; in patients whose allergic sting reactions dated back some time BDT was more frequently positive than RAST, which measures excessive serum IgE and not cell bound IgE responsible for the clinical symptomatology. As BDT--in the presence of patient serum--reflects the influences of different humoral (specific IgE, specific IgG) and cellular factors ("releasability"), it seems more appropriate to the actual clinical allergy situation than ST or RAST. Some case reports are presented to illustrate this. However, BDT does not represent an alternative to ST or RAST but a significant complement in diagnostically unclear cases and an aid in deciding to start specific venom immunotherapy, if history, ST and RAST are not sufficient. An appropriate score system ist proposed.