STUDIES ON THE IMMUNOLOGICAL MECHANISMS OF PENICILLIN ALLERGY. I. ANTIGENIC SPECIFICITIES OF GUINEA-PIG SKIN SENSITIZING RABBIT ANTI-BENZYLPENICILLIN ANTIBODIES.

The antigenic specificities of cutaneous anaphylactic reactions in guinea-pigs passively sensitized by intravenous administration of rabbit anti-benzylpenicillin (PG) sera were studied. Haptenic specificity of these reactions was found to be directed to the benzylpenicilloyl (BPO) haptenic group, and no evidence of specificity toward other possible haptenic determinants related to PG (i.e. benzylpenicillenic acid and D-penicillamine groups) was found. Specificity was mainly for the α-diastereoisomeric-BPO group, but also to one or more of the other possible diastereoisomers of BPO. Data were obtained which can be best interpreted as indicating that the BPO-specific antibodies manifest immunological specificity also for structural areas of the immunizing carrier protein (carrier specificity).