A Comparative Study on Intracutaneous and Haemagglutination Procedures for Assaying Diphtheria Antitoxin, With Special Reference to the Avidity of the Antitoxin

Abstract

Fisher( 2 ) and subsequently Stavitsky ( 7 ) have adapted the tannic acid haemagglutination technique for measuring small amounts of antiproteins as worked out by Boyden ( l ) , for estimating diphtheria antitoxin in human, rabbit, and horse sera. The method consists of sensitizing tannic acid treated red blood corpuscles with diphtheria toxin or toxoid, and agglutinating them with diphtheria antitoxic sera.Landy et al. ( 5 ) using the same method investigated the relationship between the diphtheria antitoxin titres expressed in international units as measured by the intracutaneous test, and the haemagglutination titres, using a large number of human sera and a small number of rabbit sera. They found the relationship of the logarithms of the international antitoxin units per ml and of the haemagglutination titre expressed as logarithm of the reciprocal serum dilution, to be linear. However, the slope of the line was found to deviate from 1, indicating that the titres are not directly proportional throughout the whole range.The established way of measuring the concentration of antitoxin in a serum by the intracutaneous method, and expressing it in terms of the international reference antitoxin-which is a highly avid antitoxin -is, as pointed out particularly by Jerne (4), far from being ideal. He

In Vitro Production of Antibodies by Thoracic Duct Lymphocytes

“…coli 0 1 2 7 138 antisera titrations w e r e m a d e using t h e agglutination technique of Etlzuartls & Eiuing (1957). h) Titrations of d i p h t h e r i a antitoxin were made using Ijoyden's haemagglutinatioll technique as modified h y Scheibel (1956). Sheep cells trcatcd w i t h t a n n i c acid were used t o adsorh t h e toxoid.…”

“…T h c proccdurc for adsorption w a s as follows: 1 ml o f diphtheria toxoid of t h c type previously described w a s mixed w i t h 26 ml of phosphate buffer, pH 6.4, and 9.2 ml suspension of tannic acid-treated sheep cells ( a h o u t 7 7 8 per cent). After centrifuging a n d washing t h e sediment w a s resuspended t o a volume of 3 7 ml with saline containing 4i per cent n o r m a l rahhit s e r u m (Scheibel 1960 1)) Diphtheria antitoxin w a s obtained by injecting rahhits w i t h a l u m precipitated diphtheria toxoid as follows. A total dose of 150 Lf w a s given once a m o n t h during a period of 3 months.…”

Duration of Immunity to Diphtheria and Tetanus After Active Immunization

“…Titration me2hods. Assay of the antitoxin in the serum samples was first made by the baemagiilutination method (20) using as reference the international standard preparation for in vivo determination (16). Stanifsky (21) reports good correlation between haemagglutination and neutralisation titers in human sera with 1 to 10 31' 483…”