Many hypersensitivity reactions appear to be the result of direct activation of the immune system. There is strong evidence for a role of drugs or drug metabolites as antigens or haptens in major histocompatibility complex (MHC)-restricted T-cell activation. Drugs may be conjugated to intracellular proteins and presented by MHC class I or class II molecules to CD8+ or CD4+ T-cells (164). They may also directly alter the MHC-associated peptide complex with subsequent recognition and activation of peptide-specific CD8+ T-cells (165). MHC alleles have been associated with idiosyncratic reactions to nonsteroidal anti-inflammatory agents, pyrazolone derivatives, trimethoprim-sulfamethoxazole, and contact allergens (166-169). Two recent studies used immunogenetics to approach the problem of early, and some times deadly, hypersensitivity reactions to the reverse transcriptase inhibitor abacavir used in the treatment of HIV infection (170,171). The genetic susceptibility to abacavir hypersensitivity was shown to be associated with the MHC 57.1 ancestral haplotype. However, the genetic approach to drug hypersensitivity is not new, and it has so far not led to a dramatic breakthrough in the prevention of immune-mediated drug reactions, in particular because MHC associations were difficult to reproduce. Thus, immunogenetics may complement and add to alternative diagnostic approaches, such as T-cell proliferation assays and epicutaneous tests, as none of these have much predictive value in unexposed subjects (3).
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Everything you wanted to know about. How To Cure Tennis Elbow. Are you an athlete who suffers from tennis elbow? Contrary to popular opinion, most people who suffer from tennis elbow do not even play tennis. They get this condition, which is a torn tendon in the elbow, from the strain of using the same motions with the arm, repeatedly. If you have tennis elbow, you understand how the pain can disrupt your day.