Psoriasis pathogenesis

In the pathogenesis of many chronic inflammatory diseases (e.g., rheumatoid arthritis, glomerulonephritis, colitis ulcerosa, Morbus Crohn, atopic dermatitis, psoriasis) autoimmune processes play an important role, too. Although first of all nonsteroidal antiinflammatory agents or glucocorticoids should be applied, immunosuppressive agents may also be indicated. 

Based on the recent advances in our understanding of the pathogenesis and pathophysiology of psoriasis, there was... 

Th-17 cells appear to be involved in protection against bacterial pathogens. In addition, Th-17 cells may also be crucial in the pathogenesis of various chronic inflammatory diseases that were formerly categorized as Th-1-mediated disorders. Whereas IL-17 may play an important role in the pathogenesis of psoriasis and contact hypersensitivity, its role in atopic dermatitis is still unclear [36]. In skin biopsy specimens recovered from acute and chronic skin lesions from patients with atopic dermatitis, IL-17 was preferentially associated with acute lesions [37]. 

Psoriasis is a disease of the immune system that involves T lymphocytes. The etiology and pathogenesis of psoriasis results from complex communications that cause activation of T lymphocytes and trafficking to the skin. Further reactivation causes inflammation and overproduction of skin, resulting in lesions and plaques. In psoriatic skin, there is an upregulation of intracellular adhesion molecule-1 (ICAM-1) on endothelium and keratinocytes. 

Psoriasis can occur in association with chronic juvenile arthritis as well as Reiter s syndrome. Some investigators have demonstrated a significant increase in prevalence in patients with human immunodeficiency virus infection.The pathogenesis of this relationship is imclear, but an immune recognition event may occm related to the HLA-B27 antigen. A large, retrospective, population-based study found that psoriatic arthritis is mild, imcom-mon, and not associated with a significant increase in mortality. 

The ACE inhibitors can worsen psoriasis by a mechanism mediated by inhibition of the activity of leukotrienes, which are implicated in the pathogenesis of psoriasis (73). 

The single characteristic which most adequately sums up the pathogenesis of psoriasis is the markedly increased proliferation of the epi-... 

Infliximab is a chimeric monoclonal antibody (immunoglobuhn Gj IgGi) directed against TNF-a. It binds with high affinity to the soluble and transmembranous forms of TNF-a and inhibits binding of TNF-a with its receptors. TNF-a is beheved to play an important role in the pathogenesis of psoriasis. Increased amounts of TNF-a have been found in psoriatic lesions. The proposed mechanism of action... 

The role of both T and B lymphocytes in a variety of disease states beyond transplantation has become increasingly important in the past decade. This is especially true of those diseases frequently referred to as autoimmune in their etiology, such as rheumatoid arthritis, nephrotic syndrome, systemic lupus erythematosus, inflammatory bowel disease, and so on. In addition, several other major diseases are also known to have a component of T- or B-cell-mediated pathogenesis, for example, atopic dermatitis, psoriasis, and asthma. Until very recently, the mainstay of therapy for these diseases was the corticosteroids, which were often less than satisfactory in efficacy and often associated with undesirable side effects, especially in growing children and the elderly. Thus, the search for new agents with different mechanisms of action and which did not have the same adverse event profile as conventional corticosteroids led to the subsequent evaluation of drugs such as tacrolimus and sirolimus to treat several of these diseases. 

FIGURE 62-3 Mechanisms of action of selected biological agents in psoriasis. Newer biological agents can interfere with one or more steps in the pathogenesis of psoriasis, resuiting in ciinical improvement. See text for details. 

The reason for high variability in the outcomes of treating OA with CS is due to the variation in the chain length of the polymer used in these studies. While the high-quality, long-chain CS is more effective, the low-quality, short-chain CS has minimal effects on the pathogenesis of OA. Apart from its effects of improving OA, the anti-inflammatory effects of CS have led to improvement in conditions such as psoriasis and inflammatory bowel disease. These effects... 

Nickoloff, B.J. and Nestle, F.O. (2004) Recent insights into the immiino-pathogenesis of psoriasis provide new therapeutic opportunities. The Journal cf Clinical Investigation, 113, 1664-1675. 

Chamian, F. and Krueger J G. (2004) Psoriasis vulgaris an interplay of T lymphocytes, dendritic cells, and inflammatory cytokines in pathogenesis. Current Opinion in Rheumatology, 16, 331-337. 

Paradoxical inflammation such as psoriasis is a well-known phenomenon of anti-TNFa therapy approved for the treatment of autoimmxme diseases such as rheumatoid arthritis, Crohn s disease, ulcerative colitis and psoriasis. Likewise, infliximab is used to treat refractory sarcoidosis but recently a case of infliximab-induced cutaneous sarcoidosis was reported in a patient with ulcerative colitis [150 ]. The induction of psoriasis and other clinical presentations like psoriasiform exanthema and palmoplantar pustulosis as side effects of infliximab treatment is not xmderstood and the pathogenesis of such reactions has been further obscured by the finding of a patient with Crohn s disease who developed arthritis as well as the skin manifestations cf psoriasis after the administration of infliximab [151 ]. 

Beutner, E. H., Chorzelski, T. P. and Jablonska, S. (1976). Studies on possible significance of the universal stratum corneum antibodies in the pathogenesis of psoriasis. Paper read at the 2nd International Symposium at Stanford. (In press.)... 

PPARa), an orphan nuclear receptor that acts as a transcription factor to induce the expression of enzymes involved in fatty acid oxidation (Devchand et al, 1996). Abnormal LTB4 production has been implicated in the pathogenesis of inflammatory bowel disease, psoriasis, rheumatoid arthritis, and gout. 

Vascular permeability Mimics acute and chronic inflammation Pathogenesis of psoriasis ... 

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