corticoterapia

alina.madalina
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corticoterapia

Postby alina.madalina » Mon May 11, 2015 9:12 pm

Buna! Am si eu o intrebare la care nu ii gasesc raspunsul si poate ma puteti ajuta. In tratamentul cronic cu corticoterapie are loc ca efect advers leucocitoza cu neutrofilie, pe seama cresterii limfocitelor CD8. Dar de ce se intampla asta?eu nu reusesc acum sa gasesc o explicație. Mulțumesc anticipat pt raspunsuri!

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anncush
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Re: corticoterapia

Postby anncush » Sat May 16, 2015 12:34 pm

Well, a trebuit sa caut partea cu CD8-urile pentru ca initial am crezut ca e o neintelegere cu CD18... Leucocitoza cu neutrofilie e explicata prin modularea (down-regulation) expresiei moleculelor de adeziune de suprafata (L-selectina si CD-18/Mac-1) a neutrofilelor fapt care determina "demarginatia" ; alt mecanism mentionat prin articole si care explica leucocitoza este scaderea turn-overului neutrofilelor... Partea cu CD-8 observ ca este doar o alta fateta a efectului de "redistribuire" a WBC ( leucocitoza cu neutrofilie, eozino si monocitopenie si modificarea raportului subtipurilor de Ly-T cu scaderea CD4 si cresterea CD8):

https://www-clinicalkey-com.ezproxy.umf ... 3hl0000413 (necesita user/parola Biblioteca Virtuala UMF + user/parola ClinicalKey care este in varianta FreeTrial pana pe 10 iunie)

Glucocorticoid Modulation of the Immune System

Glucocorticoids are able to modulate immune cell function by acting through intracellular GRs in immune cells[…] There is evidence to suggest that such glucocorticoid-regulated apoptosis could take place within the thymus through induction of an intrathymic glucocorticoid system because the enzymatic machinery for glucocorticoid synthesis is present within the thymus. 65 Glucocorticoids also orchestrate redistribution of circulating white blood cells with neutrophilic leukocytosis, eosinopenia, monocytopenia, and altered ratios of T-lymphocyte subtypes—resulting in decreased peripheral blood CD4 + cells and increased CD8 + cells—as well as decreased infiltration of neutrophils and monocytes into tissues. 66
[…] Monocytes and neutrophils are thought to be primary targets of glucocorticoid actions in diminishing contact hypersensitivity reactions, as evidenced by repression of monocyte production of cytokines and chemokines. 74 Glucocorticoids have also been shown to reduce DC production of interleukin-12 (IL-12), limit upregulation of co-stimulatory molecules expressed by mature DCs to reduce recognition of antigen, and strongly reduce allostimulatory capacity. 74 75 However, the suppressive effect was not observed with DCs previously activated by lipopolysaccharide (LPS), indicating that the influence of glucocorticoids depends on stage of DC maturation. 76 In a study of children with asthma, glucocorticoids were shown to decrease expression of intracellular adhesion molecule 1 (ICAM-1) and l -selectin, leading to an inhibition of the ability of immune cells to migrate to inflammatory sites. 77
In addition to effects on innate immune cells, extensive studies have shown immunomodulatory consequences of glucocorticoids on adaptive immunity. Glucocorticoids suppress differentiation and maturation of T cells as well as altering the function of T-cell subtypes, such as cytolytic (CD8 + ) and helper (CD4 + ) T cells. In addition, several studies have reported that glucocorticoids suppress mitogen- and antigen-stimulated T-cell proliferation. 78 This is thought to be most critical in T-helper (Th) cell populations, which are skewed from a Th1 toward a Th2 or other T-helper cell responses in the presence of glucocorticoids, with inhibition of TNF-α, IL-2, IL-6, IL-12, and interferon gamma (IFN-γ) production and increases in IL-10, IL-4, and IL-13 production. 79 80 81 The impact of glucocorticoids on B-cell proliferation is variable, depending on the stimulus and dose of glucocorticoids used and age-dependent expression of GRs. 82 83 In general, B-cell proliferation is suppressed by glucocorticoids to a lesser extent than T-cell proliferation, but suppression of Th2 subsets that assist in antibody production could inhibit B-cell activity. Although the overall effects of glucocorticoids on immune responses at the cellular level are immunosuppressive, this effect is attained through suppression of many stimulatory components of the immune cascade and stimulation of some immunosuppressive or antiinflammatory elements. The relatively greater sensitivity to glucocorticoid suppression of components of cellular versus humoral immunity tends to shift immune responses from a cellular to a humoral pattern, 1 which is important in SLE.

Chapter: Chapter 13 Neural-Immune Interactions Principles and Relevance to SLE
Book: Dubois' Lupus Erythematosus and Related Syndromes
Author: Francisco P. Quismorio,Karina D. Torralba
Publisher: Elsevier
Date: 2013
Slowly getting less stupid :)

alina.madalina
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Re: corticoterapia

Postby alina.madalina » Sat May 16, 2015 5:52 pm

Mulțumesc frumos pentru raspuns!


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