In vitro reactivity of penicilloyl and penicillanyl albumin and polylysine conjugates with IgE-antibody

Penicilloylated (BPO) and penicillanylated (BPA) poly-l-lysine (PLL) and human serum albumin (HSA) were prepared and characterized by penamaldate assay and proton NMR spectroscopy. The conjugates were coupled to nitrocellulose (NC) discs and cyanogen bromide activated paper discs and their in vitro reactivities with serum IgE antibodies were examined. Results showed that on paper discs, 55.3 and 83% of the sera reacted with PLL conjugates of BPO and BPA, respectively, while 41.5 and 58.1% reacted with HSA conjugates. On NC discs, HSA conjugates gave better results, 75.6 and 70.7%, respectively for BPO and BPA, compared with 38.6 and 50%, respectively for the PLL conjugates. Overall, the BPA–PLL conjugate on paper discs proved to be the most reactive preparation. Addition of the BPO–PLL paper disc preparation detected more positive sera (85.1%) and we believe that the combined use of these two specificities offers the best test for the detection of penicillin-reactive IgE antibodies.