[Antigenicity test of cefodizime sodium]

The antigenicity studies of a beta-lactam antibiotic, cefodizime sodium (THR-221), were examined in mice and guinea pigs and the following results were obtained. 1) In passive cutaneous anaphylaxis (PCA) with sera from BALB/c or C3H/He mice, a slight PCA reaction was observed only in BALB/c mice by using THR-221-ovalbumin (OVA) plus Freund's complete adjuvant (FCA) as the immunogen and THR-221 itself as the eliciting antigen. 2) Immunological cross-reactivity between THR-221 and CTX was present at the rat PCA reaction. 3) Antibodies against THR-221 were detected by PCA in guinea pigs. The anti-THR-221 antibodies gave PCA responses smaller than those of CMZ by using antibiotic plus FCA as the immunogen and the antibiotic-bovine serum albumin (BSA) as the eliciting antigen. 4) In the observation of active systemic anaphylaxis (ASA), no symptoms were observed in guinea pigs sensitized with THR-221 and provoked with THR-221-BSA. On the other hand, guinea pigs sensitized with THR-221 plus FCA by injecting THR-221-BSA showed fetal anaphylactic reactions. 5) The results of passive hemagglutination (PHA) also indicated that the PHA titer of THR-221 was lower than that of CMZ. 6) Protein binding property of THR-221 with human serum albumin was lower than other beta-lactam antibiotics. 7) Antibodies against THR-221-OVA by using THR-221-BSA as the eliciting antigen were detected in any tests above mentioned. It is concluded from these results that immunological activity of THR-221 was equivalent to the other beta-lactam antibiotics.