Antibodies titer analysis

As is documented in Table 2, the induction of anti-carbohydrate immune responses has been successfully demonstrated for many peptides. However, certain challenges remain. Often, the induced antibody titer (concentration) directed against the carbohydrate is rather weak, especially in comparison to the anti-peptide response the majority of antibodies recognize the peptide presumably in a nonmimetic conformation. Several recent studies have investigated these immime responses in more detail, with an extensive analysis of antibody isotypes and adjuvant effects [70,75], the effect of different protein carriers [194], the use of DNA vaccines [48,195], and the demonstration of protection by passive immunization [72,75,194]. In several cases, the anti-carbohydrate immune response has also been shown to be protective against infection in mice [30,72,75,78], and these cases are probably the most promising for the development of vaccines. 

If a newly developed vaccine or adjuvant is to be tested, it is important to perform array analyses of samples after administration of a dose range, which has biological relevance in relation to antibody titer, T-cell proliferation, and cytokines. This dose range needs to be established before proceeding with the array analysis. 

The most common, but by no means the only or even the most promising, immunochemical assay for small molecules is radioimmunoassay (R1A). As an overview, an immunoassay involves chemically attaching the small molecule of interest (or a derivative of it) to a carrier protein and raising specific antibody titers to it in the serum of an animal. Very dilute antibody solutions are then used to bind the small molecule which has been radiolabeled. The competition of varying known concentrations of unlabeled material is measured and the resulting standard curve used to determine unknown concentrations (Table 1). The steps leading to the development of an R1A are outlined below followed by a description of other immunochemical procedures and an analysis of the attributes and limitations of immunoassay. 

The expense of an analytical procedure depends upon much more than the cost of the final analysis. Much of the expense of an assay is related to sample preparation, and for many applications immunoassays have tremendously reduced the time needed for sample preparation. Another consideration is the amount of time needed for the development of an assay. The additional expertise which must be developed in an analytical laboratory before immunoassays can be used with confidence may seem formidable, and waiting for an animal to develop antibodies may lead to unacceptable delays in assay development. On the other hand, once a usable antibody titer is obtained, the development of a workable assay is usually straightforward. It is also likely, if immunoassays become accepted for some aspects of pesticide analysis, immunoassay kits or at least critical reagents will become commercially available. Such kits already exist for many pharmaceutical products and hormones, and numerous companies will supply antibodies to a user supplied hapten on a contract basis (83). 

A possible clue to the role of practolol-specific antibodies was found when a retrospective analysis of sera was carried out in a group of patients who had taken part in a challenge study. The pre- and post-challenge antibody titers for the five patients in the study are shown in Table 4. The titer at the height of the adverse... 

Adourian U, Shampaine EL, Hirshman CA, Fuchs 49 E, Adkinson NF Jr High-titer protamine-specific IgG antibody associated with anaphylaxis report of a case and quantitative analysis of antibody in vasec-tomized men. Anesthesiology 1993 78 368-372. 

Kinetic analysis of hydrolysis revealed a half-life of 2 min for MIC in aqueous solution, which is much slower than that for aryl isocyanates (Brown et al, 1987). Interaction of isocyanates with cholinesterases is reversible and MIC is far less potent than aryl isocyanates in this respect (Brown et al, 1987). At the same time MIC can act as a hapten leading to generation of antibodies in both animals and humans, although it results in low titers (Karol and Kamat, 1988 Karol et al, 1987). 

As outlined in Table IV, in a multivariable analysis, patients with intermediate and high risk for relapse had greatly increased rates of death compared to lower risk patients. Recipients of the second formulation of Theratope vaccine had a lower risk of death than recipients of the first formulation of vaccine. Higher IgG titers of antibody to OSM was associated with lower rates of death. Proliferative index against STn and OVACAR killing with IL2 or without IL2 stimulation were not stastically significantly different. 

Drug-specific antibodies demonstrated by Amos et al. (1977) were not confined to patients with the oculomucocutaneous syndrome. Figure 9 shows an analysis of the presence of the antibody in various patient groups and it can be seen that it occurred in most patients on long-term practolol, but the titer was higher in those patients with the oculomucocutaneous syndrome (Amos et al. 1978). 

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