In vitro titration of tetanus antitoxin

In vitro methods are used as an alternative to the expensive and time-consuming official method in mice for the titration of tetanus antibodies. Numerous techniques have been developed and used for this purpose, but with mixed results. The difficulty is to get good correlation with in vivo units whatever the vaccinal status of the individual. Today, some of these serological techniques have been virtually abandoned in favor of others which are becoming widespread. RIA is still used, but only in laboratories which already have the necessary equipment and skill. It is gradually replaced by ELISA, a rather delicate technique which however has kept its promises and is amenable to further progress. Passive haemagglutination has been greatly improved by the use of turkey erythrocytes. With this modification, this technique becomes reliable and sensitive and is apparently able to give good results for a large number of sera in case of mass investigation as well as for a quick estimate of the protective level in an individual.     

破伤风抗毒素临床反应观察报告

作者对兰州生物制品研究所常规生产的3批破伤风抗毒素（TAT）进行了临床反应观察。结果表明,TAT皮内试验假阳性反应率平均为13．3％,阳性反应率为0．9％。450例患者注射后过敏反应发生率为0,年龄,性别因素与皮试阳性率及注射后反应无相关性。     

Immunity to tetanus: tetanus antitoxin and anti-BIIb in human sera

Immunity to tetanus was investigated in 157 individuals aged between 1 and 77 years using, for the evaluation of both tetanus antitoxin and antibody to fragment BIIb (anti-BIIb), an easily performed ELISA that gave reproducible results. Among these people 72% were protected against tetanus (tetanus antitoxin titres greater than 0.06 IU ml-1). Anti-BIIb titres greater than 0.15 U ml-1 were found in 75% of the males vs 57% of the females (P less than 0.02) with marked variations according to age. Furthermore, 13 out of 41 individuals with antitoxin titres less than 0.06 IU ml-1 (not protected against tetanus) were found to have anti-BIIb titres greater than 0.15 U ml-1. These data raise questions as to the significance and protective effect of anti-BIIb against tetanus.     

Biological properties of immunochemically pure tetanus antitoxin

Immunochemically pure tetanus antitoxin obtained from enzyme-treated horse serum is less reactogenic and anaphylactogenic and possesses higher therapeutic properties than antitoxin purified by nonspecific physico-chemical methods and containing ballast antigens. Due to its increased persistence in the recipient's body, the immunochemically pure antitoxin induces passive immunity in considerably lower doses than the preparations purified by the method "Diaferm-3".     

Neonatal tetanus despite protective serum antitoxin concentration

Using the ELISA technique to estimate serum antibodies against tetanus toxin, seven neonates with clinical tetanus were found to have antibody levels 4-13 times higher than the presumed minimum protective level of 0.01 IU/ml. All but one of their mothers had been vaccinated with tetanus toxoid in pregnancy. In two other neonates, whose mothers had received multiple booster doses of toxoid during pregnancy, the anti-toxin concentrations were 100- and 400-times the presumed protective level. Therefore the toxin dose may overwhelm the pre-existing anti-toxin level and produce disease. Furthermore, multiple booster injections of tetanus toxoid may not only enhance serum anti-toxin titres, but could also lead to an ineffective immune response.     

Titration of tetanus antitoxin by passive hemagglutination. II. Serological characteristics of antitoxin production in rabbits and monkeys.

1) Production of tetanus antitoxin in rabbits and monkeys was followed by passive hemagglutination (HA) and toxin-neutralization (TN) tests. The HA activity was observed in both IgM and IgG in both animal species. 2) In rabbits, IgM antitoxin was detected as early as in 7 days, reached the maximum titer in 10--14 days, and disappeared in 3 weeks after the primary immunization. Antitoxin of IgG class was detected in 10 days, and increased gradually. The ratio of HA/TN titers ("serum ratio") was high at an early stage of primary immunization and approached the unity in 3--4 weeks. Unlike the case of guinea pigs, IgM was found to contribute greatly to this high level of ratio. Besides, most rabbits produced IgG antitoxin of high ratios at early stages of immunization. 3) The immune response of monkeys showed a pattern very similar to that of rabbits except a few days' delay in the time course of antitoxin titers. No IgG antitoxin with a high serum ratio was demonstrated. Therefore, the high serum ratio of early sera could be accounted for mainly by IgM. 4) In response to the secondary immunization, no IgM antitoxin was detected in either animal species. 5) No definite correlation between serum ratio and avidity in terms of "dilution ratio" was demonstrated. However, both the dilution ratio and serum ratio were high at an early stage of immunization and gradually decreased, though the magnitudes of the ratios were variable depending on individual animals.