Immunopathological reactions

Type n immunopathologic reactions involve destruction of host cells (usually blood cells) through cytotoxic antibodies by one of two mechanisms (see Fig. 86-1). First, the drug binds to the cell as a hapten (e.g., the platelet or red blood cell). Antibodies (IgG or IgM) specific for the... 

Since their introduction to therapy, the question of allergic cross-reactivity between cephalosporins and penicillins has been raised, and continues to be raised for each of the new cephalosporin molecules introduced (Petz 1971 Pevny et al. 1973). Immunopathological reactions to cephalosporins have been reported and often confirmed by objective tests. It is, however, frequently difficult to assess whether such reactions are due to cross-reactivity on the basis of preexisting penicillin hypersensitivity or whether it is the manifestation of a de novo sensitization to cephalosporin. 

Most of the serum complement proteins are produced primarily in the liver, but monocytes and macrophages constitute an important source of extrahe-patic production of many complement components. Local production of complement at tissue sites of inflammation may be of considerable importance in host defences and immunopathological reactions. 

Impurities that cause the greatest concern are those that are toxic, defined by the US Pharmacopeia (USP) as impurities that have significant undesirable biological activity [ 1 ], and host cell contaminants in biopharmaceuticals that have potential risks of allergic reaction or other immunopathological effects [2]. 

K15. Krishman, C., and Kaplan, M. A., Immunopathologic studies of systemic lupus erythematosus. II. Antinuclear reaction of y-globulin eluted from homogenates and isolated glomeruli of kidneys from patients with lupus nephritis. J. Clin. Invest. 46,569-579 (1967). 

Although the mechanism of this adverse effect was purely speculative, it was suggested that interferon alfa might have induced a reaction similar to the immunopathologi-cal mechanism involved in serositis associated with systemic lupus erythematosus. 

Introduction - The immunopathologic events involved in an asthmatic attack can be generally classified as a Type I imnediate hypersensitivity reaction involving specific antigen bridging receptive IgE immunoglobulins bound to host mast cells and basophils that culminates in the release of various pharmacologic mediators. The mechanisms responsible for the release of these mediators have been extensively reviewed. "3... 

PATTERSON, R ZEISS, C.R. PRUZANSKY, J.J. (1982) Immunology and immunopathology of trimellitic anhydride pulmonary reactions. Journal of Allergy and Clinical Immunology, 70, 19-23. 

The mechanism by which PUVA induces photosensitivity is not known. The action spectrum for oral PUVA is between 320 and 400 nm. Two distinct photoreactions take place. Type I reactions involve the oxygen-independent formation of mono- and bifunctional adducts in DNA. Type II reactions are oxygen-dependent and involve sensitized transfer of energy to molecular oxygen. The therapeutic effects of PUVA in psoriasis may result from a decrease in DNA-dependent proliferation after adduct formation. Perhaps more importantly, PUVA can alter cytokine profiles and cause immunocyte apoptosis, thereby interrupting immunopathologic processes. 

Immunopathological Mechanisms and Clinical Aspects of Allergic Reactions... 

D. Immunopathological Mechanisms of Allergic Reactions to Drugs I. Antibody-Mediated Reactions... 

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