In vitro quantification of cross-reactivity between beta-lactam antibiotics and anti-benzylpenicillin antibodies.
The phenomenon of cross-reactivity between allergens and anti-antibodies is believed to be a major factor underlying the incidence of immunologically mediated adverse reactions. A sensitive reproducible competitive enzyme-linked immunosorbent assay (ELISA) has been developed for the quantitative determination of the extent of cross-reactivity occurring between native beta-lactam antibiotics and anti-benzylpenicillin serum antibodies (anti-BPAbs) raised in presensitized rabbit serum in which free native antibiotic at a concentration of 3 mm, and benzylpenicillin cytochrome c (BPCC) adsorbed onto a solid surface, compete to bind free anti-BPAbs. The extent of BPPC-anti-BPAb binding is determined spectrophotometrically, following the addition of enzyme-labelled antispecies antiglobulin and a suitable substrate. The assay has been used to determine the levels of cross-reactivity exhibited by 29 commercially available beta-lactam antibiotics (14 penicillins and 15 cephalosporins), with results attained ranging for the penicillins between 9.1 and 100% and for the cephalosporins from 0.0 to 19.9%. The results thus indicate that cross-reactivity between different beta-lactams and anti-BPAbs does occur in vitro and that different beta-lactams cross-react to different extents, with cephalosporins cross-reacting less than the penicillins.
Bartlett
A
A
School of Pharmacy, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF UK.
Dearden
J C
JC
Sibley
P R
PR