Cell-mediated reactions

During the past decade, a lot of data on the pathogenesis of non-immediate reactions induced by RCM has indicated that the majority of these reactions are T-cell-mediated reactions (table 2) ... 

Kanny G, Pichler W, Morisset M, et al T-cell-mediated reactions to iodinated contrast media evaluation by skin and lymphocyte activation tests. J Allergy Clin Immunol 2005 115 179-185. 

As previously indicated, the primary cells involved in the immune response are lymphocytes which have a centrally located round nucleus, lack specific granules, and have a basophilic cytoplasm containing free ribosomes. The (thymus-dependent) T-lyniphocytes are involved in cell mediated reactions and also interact with B-Iymphocytes (see later) to regulate the production of antibody, The B cells differentiate into the antibody-producing plasma cells. There is growing evidence that neither T... 

As can be seen from Table 13.3, the p-lactams have been implicated in a wide variety of allergic ADRs, but in many cases these reactions do not fit into the traditional Cell and Goombs classification. As was discussed earlier these ADRs are more than likely a result of both IgE- and T-cell mediated reactions and constitute potential immediate, late, and delayed hypersensitivity responses. For the remainder of this chapter we will focus on the IgE-related reactions since we have the greatest understanding of the pathogenesis of such ADRs in p-lactam antibiotics. 

D. Type IV Drug Allergy Type IV allergy is a cell-mediated reaction that can occur from topical application of drugs. It results in contact dermatitis. 

Oxatomide thus appears in the rat studies to be a specific and orally active antagonist of mast cell-mediated reactions. 

Cell-mediated reactions can also be demonstrated in vitro by the macrophage inhibition test. With the exception of penicillin sensitivity, this test has seldom been employed in the investigation of drug allergies. The possibilities and limitations of... 

The frequent positive nature of cell-mediated reactions in type I reactions These observations decrease to some extent the value of tests specific for type I-... 

Morbilliform exanthema, fixed drug eruptions, and erythrodermia are thought to result from a cell-mediated reaction, i.e., T-lymphocytes as in contact sensitivity. However, the histologic pictures of both reactions differ in a number of features. Moreover, basophil infiltration, which is rather important in contact sensitivity, is often negligible in the tuberculin reaction. In spite of several differences between... 

As shown by Rocklin et al. (1974), B-lymphocytes as well as T-cells showed the capacity to produce the inhibitory factor when put in contact with mitogens or specific antigens. Therefore, lymphokine production could result from both humoral imune reactions and cell-mediated reactions. 

The majority of reactions observed, particularly the local ones, have been attributed to the impurities present in the injected products. However, we now know that insulin itself can be responsible for sensitization (Minars et al. 1974 Diem and Teuscher 1979). Insulin is composed of 51 amino acids divided into two chains chain A is composed of 21 amino acids and chain B of 30. It appears that the antigenic properties of insulin and the formation of anti-insulin antibodies are linked to chain A (Halpern and Bourdon 1966) but an epitope on Chain B is probably involved in cell-mediated reactions (Faulk et al. 1975 MacCuish et al. 1975). 

Various investigators (Halpern et al. 1967 Federlin et al. 1969 Federlin 1971 Feinglos and Jegasothy 1969 Faulk et al. 1975 MacCuish et al. 1975 Diem and Teuscher 1979 Diem et al. 1982) have shown that insulin of porcine or bovine origin can induce lymphocyte transformation in lymphocytes from diabetic patients with both immediate- or delayed-type hypersensitivity to commercial insulin. Such cell-mediated reactions to insulin in vitro have also been reported in untreated diabetics they are rather common in insulin-treated diabetics even without any evidence of allergy in vivo (MacCuish et al. 1975). 

Endogenous N-nitrosation may result from cell-mediated reactions, involving alveolar and peritoneal macrophages, bacteria, and yeasts [5,58,59]. In earlier investigation, dimethylamine was used to determine... 

Delayed, that is type IV, T cell-mediated reactions are seen. Some NSAID-induced delayed reactions occur as contact dermatitis, fixed drug eruption, DRESS, acute generalized exanthematous pustulosis, SJS, TEN, and nephritis. 

The bonding ability of BG is due to the chemical reactivity of the BG through interfacial and cell-mediated reactions in which silicon bonds are broken and a CP-rich layer is formed on the top of the glass, which crystallizes to HCA [13],... 

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