Psoriasis enzyme levels

Infliximab (Remicade) is a chimeric monoclonal antibody directed against TNF-a. Recently, its indications have been expanded to include psoriatic arthritis and treatment of adults with chronic severe plaque psoriasis. An advantage over other systemic psoriasis treatments is that infliximab does not adversely affect blood counts, hepatic enzyme levels, or kidney function. The recommended dose is 5 mg/kg as an IV infusion at weeks 0, 2, and 6, then every 8 weeks thereafter. For psoriatic arthritis, it may be used with or without methotrexate. Adverse effects include headaches, fever, chills, fatigue, diarrhea, pharyngitis, upper respiratory and urinary tract infec-... 

The most common adverse effects of infliximab are headaches, fever, chills, fatigue, diarrhea, pharyngitis, upper respiratory and urinary tract infections, and hypersensitivity reactions (urticaria, dyspnea, and hypotension). Infliximab has been also associated with infections and lymphoproliferative disorders. It is not associated with end-organ toxicity, and blood counts, liver enzyme levels, kidney function, and complement values can be expected to remain normal during treatment. This gives it a major advantage over other systemic psoriasis treatments. 

The process of nucleic acid breakdown presumably starts a little before entry of the cell into the granular layer. Histochemically, however, most lysosomal enzymes are strongest at the level of the granular layer (B28). The amount of DNA in psoriatic epidermis is equivalent per unit weight to normal epidermis, but about one-third of the nuclear DNA is still present in the parakeratotic horny layer of psoriasis while practically none is found in normal stratum corneum. RNA is much increased in psoriatic epidermis (M12, R5), and it also can be found in increased amounts in the psoriatic scale (Table 6). 

Experiments by Bickers and Kappas (1978), Li et al. (1995) and Genevois et al. (1998) have examined the role of AHH and cytochrome P450 in the metabolism of coal tar products. A coal tar solution (crude coal tar diluted to 20% with ethanol and polysorbate 80) was applied to clinically unaffected skin of three patients with severe atopic dermatitis and six patients with generalized psoriasis (Bickers and Kappas 1978). Another skin area at least 10 cm away was not treated or was treated with 100 mL of the vehicle alone. Twenty-four hours later, a 6-mm punch biopsy was obtained from coal tar treated and control areas and the effect on AHH activity was determined. Application of coal tar to the skin caused induction of cutaneous AHH activity that varied from 2.4-5.4-fold over the enzyme activity in untreated skin areas. There were no sex differences in inducibility between patients with psoriasis and patients with atopic dermatitis. Relative inducibility of human skin AHH by coal tar did not appear to be a function of the basal level of the enzyme. 

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