fibrin and Dermatitis--Atopic

Atopic dermatitis is a chronic inflammatory skin disease caused by complex multifactorial etiology. In the recent years, there have been significant advances in tissue engineering and the generation of in vitro skin models representative of healthy and diseased states. This chapter describes the methodology for the fabrication of in vitro human skin equivalent (HSE) from human keratinocytes and fibroblasts using a fibrin-based dermal matrix and serum-free culture conditions. Modification of the culture conditions with the supplementation of Th2 cytokines such as interleukin-4 induces the development of atopic dermatitis-like skin model. The chapter also describes the histological and immunohistochemical tools for characterization of the HSE model. The reconstruction of tissue-engineered HSE models that recapitulate the essential features of atopic dermatitis provides powerful tools for deeper understanding of the underlying pathological mechanisms on epidermal level, identification and testing of novel treatment options, and safety and toxicological evaluation in a pathophysiologically relevant system.

Topics: Cells, Cultured; Cytokines; Dermatitis, Atopic; Fibrin; Fibroblasts; Humans; Keratinocytes; Models, Biological; Skin; Skin, Artificial; Tissue Engineering

Myocardial infarction and ischemic stroke are associated with formation of dense fibrin clots resistant to lysis. Although pro- and antithrombotic alterations have been reported in atopy, fibrin clot function has not been studied in atopic patients. The aim of the current study was to investigate fibrin clot properties in patients with atopic dermatitis (AD). Plasma fibrin clot permeability, turbidity and clot lysis were assessed in 130 consecutive AD patients, aged 29.7 +/- 11 [+/-SD] years (mean SCORAD index, 32.4 +/- 14.9), free of thrombotic events. A control group comprised 130 healthy controls matched for demographics. Patients with AD had lower clot permeability (7.12 +/- 1.87 vs. 9.32 +/- 0.86 x 10(-9) cm(2); P < 0.0001), increased fiber thickness (maximum clot absorbancy at 405 nm, 4.03 +/- 0.54 vs. 3.47 +/- 0.25), faster clot formation (the lag phase, 39.16 +/- 4.61 vs. 43.05 +/- 4.56 s), higher maximum D-dimer levels released from clots, reflecting increased clot mass (4.05 +/- 0.57 vs. 3.47 +/- 0.25 mg/l; P < 0.0001), lower rate of D-dimer release (0.073 +/- 0.01 vs. 0.078 +/- 0.01 mg/l/min; P < 0.0001), and prolonged fibrinolysis time (9.26 +/- 1.47 vs. 7.81 +/- 1.17 min; P < 0.0001) compared with controls. Concomitant asthma (n = 36; 27.7%) was related to a higher rate of D-dimer release from clots than the remainder (0.075 +/- 0.01 vs. 0.072 +/- 0.01 mg/l/min, respectively; P = 0.03). Altered plasma fibrin clot properties associated with reduced efficiency of fibrinolysis can be detected in AD patients, which might represent a novel mechanism that modulates a hemostatic balance in atopy.

Topics: Adolescent; Adult; Asthma; Biomarkers; Blood Coagulation Tests; Case-Control Studies; Chi-Square Distribution; Dermatitis, Atopic; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinolysis; Humans; Logistic Models; Male; Poland; Thrombosis; Young Adult

Glycocalyx collapses during dehydration to produce electron-dense accretions. Confocal laser scanning microscopy (CLSM) may be used to visualize fully hydrated microbial biofilms.. Using CLSM, to analyse glycocalyx production by Staphylococcus aureus cells in skin lesions of bullous impetigo, atopic dermatitis and pemphigus foliaceus. A second objective was to compare numbers of S. aureus cells in tissue sections prepared by different methods for routine light microscopy.. S. aureus cells in skin lesions of impetigo, atopic dermatitis and pemphigus were stained with safranin, and positive staining with fluorescein isothiocyanate-conjugated concanavalin A was considered to indicate the presence of glycocalyx.. All S. aureus cells tested in skin lesions of impetigo, atopic dermatitis and pemphigus were covered with glycocalyx and formed microcolonies. The numbers of S. aureus cells in a routine light microscopy section were significantly lower than those in a frozen section that had not been dehydrated with ethanol.. S. aureus cells generally produce glycocalyx in skin lesions of bullous impetigo, atopic dermatitis and pemphigus foliaceus, which accounts for the difficulty of removing S. aureus cells from these skin lesions. The glycocalyx may collapse during dehydration and most of the S. aureus cells may be carried away during preparation of routine light microscope sections.

Topics: Acetic Acid; Adolescent; Adult; Aged; Biofilms; Child; Child, Preschool; Colony Count, Microbial; Dermatitis, Atopic; Female; Fibrin; Fusidic Acid; Glycocalyx; Humans; Hydrochloric Acid; Impetigo; Male; Microscopy, Confocal; Middle Aged; Pemphigus; Staphylococcus aureus

Cutaneous deposits of fibrinogen activity in lesional skin, plasmatic fibrinolytic activity, and antiplasmin activity (alpha 2 macroglobulin, alpha 1 antitrypsin and antithrombin III) were evaluated in a group of ten patients with atopic dermatitis and in a sex- and age-matched control group. Plasma fibrinolytic activity was increased in the acute phase of the disease (p less than 0.05). The levels of circulating antiplasmins appeared similar in the patients and the control group. Cutaneous fibrinolytic activity was increased in the acute phase of the disease in 5 of 5 cases, suggesting a role of the fibrinolytic system in the amplification of the inflammatory phenomenon in that phase of the disease. In the chronic lichenified phase, CFA was decreased in 3 of 5 cases leading to an excessive deposit of fibrin in the skin. This could be correlated with the abnormal vascular response (blanching phenomenon). On the basis of these data, the therapeutic use of the antifibrinolytic agents only seems rational in the acute phase of the disease.

Topics: Acute Disease; Adolescent; Adult; alpha-2-Antiplasmin; Child, Preschool; Dermatitis, Atopic; Female; Fibrin; Fibrinolysis; Humans; Male; Plasminogen Activators; Skin