[Basophil activation test in the diagnosis of allergy to medicines].

In this paper we study the reliability of the basophil activation test (BAT) in the "in-vitro" diagnosis of allergy to betalactams and to metamizol, and the sensitivity and specificity of the technique are analyzed. To this end, we studied 58 patients allergic to betalactam antibiotics with a positive cutaneous test facing any derivative of penicillin and 30 healthy controls who tolerated betalactams, and 26 patients allergic to metamizol with an immediate reaction and 30 healthy controls who tolerated the medicine. Sensitivity to BAT in allergy to betalactams was 52.8%, and specificity was 92.6%. For metamizol, sensitivity was 42.3% and specificity was 100%. The positive predictive value of BAT in allergy to betalactams was 18.9% and the negative predictive value was 98.4%. For metamizol, the positive predictive value of the technique was 100% and the negative predictive value was 99.4%. The joint use of BAT and CAP (specific IgE) makes it possible to diagnose some 65% of patients allergic to betalactams. The combined use of cutaneous tests and BAT in allergy to metamizol detects 70% of the cases. BAT is a useful, non-invasive technique in the "in-vitro" diagnosis of allergy to betalactams and metamizol.