Mast cell hyperplasia

Mast cell hyperplasia can affect several organ systems. Regarding the liver, 50% of cases present as hepatomegaly. Mast cell infiltrates are found in the portal fields. They can lead to occlusion of the small vessels with subsequent fibrosis or cirrhosis. (112) Moreover, there is evidence of marked lymphadenopathy and skin lesions. Polygonal cells with eosinophilic granules are... 

Taken together, the identification of mast cell hyperplasia and mediator release at sites of tissue fibrosis and wound healing, observations in animal models, and study of the actions of mast cell products, has provided much circumstantial evidence that mast cells are involved in tissue remodelling, healing and fibrosis. It is unlikely that mast cells are essential in these responses, but more likely that they augment them. Complex interactions between different connective tissue components, mast cells and other inflammatory cells are likely to operate, and are unlikely to be fully delineated in humans in vivo. It seems reasonable to hypothesize however that initial mast cell mediator release has the potential to activate fibroblasts, which may then promote the recruitment at d proliferation of further mast cells, explaining the mast cell hyperplasia often witnessed at sites of chronic inflammation. 

Costa JJ, Demetri GD, Harris TJ. Dvorak AM. Hayes DF, Merica EA, Menchaca DM. Gringeri AJ. Schwartz LB, Galli SJ Recombinant human stem cell factor (kit ligand) promotes human mast cell and melanocyte hyperplasia and functional activation in vivo. J Exp Med 1996 183 2681-2686. 

Cyclosporine demonstrates immunosuppressive activity by inhibiting the first phase of T-cell activation. It also inhibits release of inflammatory mediators from mast cells, basophils, and polymorphonuclear cells. It is used in the treatment of both cutaneous and arthritis manifestations of severe psoriasis. The usual dose is between 2.5 and 5 mg/kg/day given in two divided doses. Adverse effects include nephrotoxicity, hypertension, hypomagnesemia, hyperkalemia, alterations in liver function tests, elevations of serum lipids, GI intolerance, paresthesias, hypertrichosis, and gingival hyperplasia. Cumulative treatment for more than 2 years may increase the risk of malignancy, including skin cancers and lymphoproliferative disorders. 

As described so far, mast cells were found to exacerbate immune reactions, including allergic responses. A recent paper shows that mast cells are also critical to limit pathology in a murine CHS model, including the reduction of infiltrating cells, epidermal hyperplasia, and necrosis... 

Specifically, the giant papillae found in VKC consist of dense fibrous tissue (connective tissue hyperplasia) as well as eosinophils, mast cells, basophils, polymorphonuclear leukocytes, lymphocytes, and macrophages. Mucous discharge contains eosinophils. Trantas dots, which appear as elevated white opacities at the limbus, contain eosinophils and epithelial cells. 

Goto T., Befits, D. Low, R, and Bienenstock, J. (1984). Mast cell heterogeneity and hyperplasia in bleomycin-induced... 

K. C. (2005) Titanium dioxide particle-induced goblet cell hyperplasia association with mast cells and IL-13. Respiratory Research, 13(6), 34. 

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