The importance of disease associations and concomitant therapy for the long-term management of psoriasis patients

It is well established that several inflammatory-type conditions, such as arthritis, diabetes, cardiovascular disease, and irritable bowel disease exist comorbidly and at an increased incidence in patients with psoriasis. Psoriasis and other associated diseases are thought to share common inflammatory pathways. Conditions such as these, with similar pathogenic mechanisms involving cytokine dysregulation, are referred to as immune-mediated inflammatory diseases (IMIDs). Considerable evidence for the genetic basis of cormobidities in psoriasis exists. The WHO has reported that the occurrence of chronic diseases, including IMIDs, are a rising global burden. In addition, conditions linked with psoriasis have been associated with increasing rates of considerable morbidity and mortality. The presence of comorbid conditions in psoriasis patients has important implications for clinical management. QoL, direct health care expenditures and pharmacokinetics of concomitant therapies are impacted by the presence of comorbid conditions. For example, methotrexate is contraindicated in hepatic impairment, while patients on ciclosporin should be monitored for kidney function. In addition, some agents, such as beta blockers, lithium, synthetic antimalarial drugs, NSAIDs and tetracycline antibiotics, have been implicated in the initiation or exacerbation of psoriasis. Consequently, collaboration between physicians in different specialties is essential to ensuring that psoriasis treatment benefits the patient without exacerbating associated conditions

Adhesion of human mast cells to extracellular matrix provides a co-stimulatory signal for cytokine production

Engagement of integrin receptors during cell adhesion leads to changes in the morphology and the state of activation of cells. We therefore examined whether mast cell adhesion to extracellular matrix proteins affects the synthesis and release of various proinflammatory cytokines. Cells of the human mast cell line HMC-1 were added to fibronectin (FN)-, vitronectin (VN)- or, as a control, bovine serum albumin (BSA)-coated wells and were stimulated with phorbol 12-myristate 13-acetate (PMA) and/or calcium ionophore A23187 (ionophore). Cytokine production was evaluated using semiquantitative reverse transcription–polymerase chain reaction (RT–PCR) analysis of cell extracts and enzyme-linked immunosorbent assay (ELISA) analysis of cell supernatants. After a 4-hr incubation, mRNA expression of interleukin (IL)-8 (and weakly of IL-6) was up-regulated in matrix-adherent cells, with further increase in the presence of PMA and/or ionophore, compared with unstimulated cells. High-level de novo expression of IL-3 and of granulocyte–macrophage colony-stimulating factor (GM-CSF) was observed mainly in matrix-adherent cells. These changes were paralleled by the secretory pattern of HMC-1 cells after a 24-hr stimulation. Unstimulated cells adherent to FN or VN had already released small amounts of IL-8, and both VN- and FN-adherent cells produced, almost invariably, a higher level of cytokines than BSA-exposed cells after additional stimulation. These results show that mast cell adhesion to matrix proteins by itself has only selected and minor effects, but additional activation of mast cells by secretory stimuli causes significantly enhanced cytokine gene expression and secretion, suggesting that mast cells are far more active in their natural tissue environment than hitherto suggested from data in suspension cultures