The role of eosinophils in the pathogenesis of atopic dermatitis ‐ eosinophil granule proteins as markers of disease activity

Abstract

Currently, there is a large body of evidence that atopic dermatitis (AD) has an Immunologic basis. Atopy‐specific helper T cells (Th2‐like T cells) may play a pathogenetic role by producing and releasing cytokines relevant for the allergic inflammation, such as IL‐4, IL‐5, and other growth factors. Eosinophils are believed to be of major importance as effector cells mediating the pathogenetically relevant late‐phase reaction which is associated with a significant destruction of the surrounding tissue. Accordingly, a significant preactivation of peripheral blood eosinophils was detected in AD patients, leading to an enhanced susceptibility of these cells to distinct stimuli such as IL‐5. Toxic proteins, such as eosinophil cationic protein (ECP), contained in the matrix and the core of secondary granules of eosinophils, may play an important role by propagating the allergic inflammatory process and by modulating the immune response. The pathogenetic role of eosinophils in AD is further supported by the detection of these proteins in the eczematous skin of patients. Furthermore, recent data point to a significant correlation between disease activity and deposition of eosinophil granule content: ECP serum levels were significantly increased in AD patients. In addition, ECP levels correlated with the disease activity. Moreover, clinical improvement was associated with a decrease of both the clinical score and serum ECP levels. These data clearly indicate that activated eosinophils may play a major role in the allergic inflammatory process of AD. Therefore, modulation of eosinophil activation could prove to be an important pharmacologic modality for the treatment of AD.

Vegetarian Diet Ameliorates Symptoms of Atopic Dermatitis through Reduction of the Number of Peripheral Eosinophils and of PGE2 Synthesis by Monocytes.

“…The number of eosinophils and neutrophils decreased prior to amelioration of dermatitis. Since eosinophils are inflammatory cells, which in part form dermatitis (Liferman et al, 1985;Kapp, 1993;Liferman, 1994), it is conceivable that the decrease in their number is one of the reasons for the ameliorative effect. Previous studies reported that a low calorie diet or fasting causes a reduction in the number of neutrophils in the peripheral blood (Powanda, 1977), so that, a low calorie diet may also be related to a reduction in the number of eosinophils, although it has not been demonstrated previously.…”

“…In order to clarify the mechanisms through which skin inflammation was suppressed, the number of eosinophils, which are inflammatory cells playing a major role in the development of dermatitis and skin irritability (Liferman et al, 1985;Kapp, 1993;Liferman et al, 1994), was counted every two weeks during the therapy. The SCORAD index decreased at 2 weeks after hospitalization and then continued to decline slowly up to 8 weeks as shown in Fig.…”

Safety and Efficacy of 1 Year of Tacrolimus Ointment Monotherapy in Adults With Atopic Dermatitis

“…There are no biochemical markers for atopic dermatitis, but patients typically have elevated serum IgE levels, eosinophil counts, and lactate dehydrogenase concentrations. [1][2][3][4] Topical corticosteroids are the standard treatment for acute lesions of atopic dermatitis. However, they carry a risk of local side effects such as skin atrophy and striae and systemic side effects.…”

Clinical correlations of recent developments in the pathogenesis of atopic dermatitis

“…96,97 Although, human eosinophils express several chemokine receptors including CCR2, CCR3 and CXCR4, most studies have indicated the importance of CCR3 in the development of human AD and mouse models of AD. The ligands associated with CCR3 linked to the development of human AD include CCL5, CCL11, CCL13 and CCL26.…”