Antibodies homocytotropic

Hammer, D. K., Kickhoefen, B. and Schmid, T. 1971. Detection of homocytotropic antibody associated with a unique immunoglobulin class in the bovine species. Eur. J. Immunol. 1, 249-257. 

Wells, P. W. and Eyre, P. 1971. Preliminary characterization of bovine homocytotropic antibody. Immunochemistry 9, 88-90. 

Tada, T., Okumura, K., Platteau, B. and Bazin, H. (1975). Half-lives of two types of rat homocytotropic antibodies in circulation and in the skin. Int. Arch. Allergy Appl. Immunol. 48, 116-131. 

In recent years there have been significant advances in the characterization of immune responses induced by chemical allergens. Despite such progress it must be acknowledged that a consensus regarding the immunobiological mechanisms that, in practice, result in respiratory sensitization has yet to be achieved. At the centre of the debate are questions regarding the importance of IgE and other homocytotropic antibody in the development of sensitization. This and other priority areas for further research are listed below. 

The development and/or acceptance of experimental animal models for the elucidation of relevant mechanisms requires that the immunological basis or bases for occupational respiratory allergy to chemicals are understood. A major achievement would be the final resolution of the relative importance of homocytotropic antibodies and other immune mechanisms in respiratory sensitization to chemicals. 

The antibodies involved in anaphylactic sensitization are called cytotropic antibodies. Those able to passively sensitize animals of another species are called heterocytotropic while those able to sensitize only members of the same or closely related species are called homocyto-tropic. Heterocytotropic antibodies are primarily IgG, while homocy-totropic antibodies belong primarily to the IgE class (Ishizaka and Ishizaka, 1966 Johansson, 1967 Vaz and Ovary, 1968). IgG homocytotropic antibodies have been demonstrated in animals such as guinea pig (Amkraut et al., 1973), rat (Bach et al., 1971), and mouse (Vaz and Ovary, 1968). In humans, although there are reports claiming the exis-... 

This test relies on the capacity of homocytotropic antibodies or reagins to fix to human skin and be detected by subsequent injection of the suspected allergenic drug. Although a positive reaction is not immediately indicative of the involvement of IgE antibodies, their presence is often inferred if skin sensitization is prevented by prior heating of the serum to 56 °C. Prior to the realization of the possibility of the transfer of blood-borne viruses, and the introduction of easier-to-carry-out tests that specifically identify IgE, the P-K test was used in studies aimed at determining whether or not the antibody was implicated in some adverse reactions to iodinated contrast media. In one case study, a positive P-K test was taken as evidence... 

Inhibition of homocytotropic antibody responses in adult inbred mice ly previous feeding of the specific antigen. J. Aller Clin. Immunol. 60 110-115. 

The presence of an evolutionary precursor of IgE has not been demonstrated. Homocytotropic antibodies have, however, been identified in lower species. For example, a pigeon hyperimmune to BSA responded to intracutaneous injection of the antigen with an immediate hypersensitivity reaction characterized by increased capillary permeability to a dye (117). Responsiveness was passively transferred to a nonim-mune pigeon, and the responsible serum factor was heat labile. The minimal latent period after passive transfer varied among pigeons from 24 to 72 hours reactions could be detected as much as 14 days later... 

Homocytotropic antibodies have also been observed in the duck, where it was found in a 7.8 S fraction (111). There is, at present, insufficient evidence to establish a direct relationship to mammalian IgE. 

The likelihood of elicitation of an IgE response to an antigen is enhanced by inoculation into the footpads (126-128). As indicated earlier, certain parasites induce the formation of relatively high titers of the homocytotropic antibody. Reports vary as to the possibility of elicitation of an anamnestic response. 

One of a series of arylhydroxytriazenes, PR-H-986 BS (JL) was effective in both hvimoral and cell-mediated immune responses and in rat adjuvant-induced arthritis.97 The orally active antiviral agent tilerone (2), effectively inhibited symptoms of adjuvant arthritis and allergic encephalomyelitis in rats but paradoxically, it potentiated the humoral immune response to the thymus dependent and Independent antigens as well as to homocytotropic antibody.98... 

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