Correlation of the severity of atopic dermatitis with absolute eosinophil counts in peripheral blood and serum IgE levels.

BACKGROUND: Although a number of epidemiological studies, showing incidence and prevalence of atopic dermatitis, were available, scant attention has been paid to the correlation between the parameters of the disease like severity, absolute eosinophil count and IgE level, which has been known to be associated inconsistently. Hence this study was undertaken. METHODS: A total of 102 patients of atopic dermatitis, both children and adults, and 107 age matched controls were studied at the Pediatric Dermatology clinic, Institute of Child Health and department of Dermatology, AMRI-Apollo hospitals, Kolkata. RESULTS: The average age of onset of atopic dermatitis was observed to be 4.55 years. Both the average absolute eosinophil count and IgE levels in patients of atopic dermatitis were significantly higher than that of the controls. Each of these parameters showed significant correlation with severity of the disease and showed a nonhomogeneous distribution reflected by significant association with personal history of bronchial asthma and family history of atopy, when both parents were atopic. CONCLUSIONS: Our study shows that clinical activity of the disease as recorded by the "SCORAD" index can be used as an indicator of the hematological abnormalities as well as to some extent as a prognostic indicator. Family history of atopy correlates with the hematological abnormalities only if both parents are involved and bronchial asthma is the only associated atopic condition which correlates with the parameters of the disease .

Increased type 2 cytokine expression by both CD4+ CD45RO+ T cells and CD8+ CD45RO+ T cells in blood circulation is associated with high serum IgE but not with atopic dermatitis.

Type 2 cytokines, such as interleukin-4 (IL-4) and IL-13, are associated with immunoglobulin E (IgE) production. This association has also been observed in CD8+ T cells from patients infected with leprosy and human immunodeficiency virus (HIV). Using intracellular cytokine staining and flow cytometry, the cytokine profile [IL-2, IL-4, IL-10, IL-13, and interferon (IFN)-gamma] of both CD4+ and CD8+ memory/effector T cells circulating in atopic dermatitis (AD) patients was investigated at the single cell level. The levels of type 2 cytokines in CD4+ T cells or CD8+ T cells in AD patients with high levels of serum IgE (AD-H), low levels of serum IgE (AD-L), and healthy controls were compared. Increased production of IL-4 and IL-13 in both CD4+ CD45RO+ T cells and CD8+ CD45RO+ T cells after 4 h in vitro stimulation with phorbol 12-myristate 13-acetate and ionomycin, was more prominent in AD-H patients than in AD-L patients or healthy controls, whereas IFN-gamma-producing CD4+ CD45RO+ T cells and CD8+ CD45RO+ T cells were relatively diminished in AD-H patients. CD4+ T cells and CD8 + T cells from AD-H patients, cultured for 48 h with phorbol 12-myristate 13-acetate and ionomycin, released larger amounts of IL-4 and IL-13 but smaller amounts of IFN-gamma than both types of cells from AD-L patients or healthy controls. In addition, when stimulated with immobilized anti-CD3 monoclonal antibody (MoAb) and anti-CD28 MoAb, CD4+ CD45RO+ T cells and CD8+ CD45RO+ T cells from AD-H patients contained more IL-4-producing cells but fewer IFN-gamma-producing cells compared with healthy controls. Finally, spontaneous mRNA expression of IL-4 in blood CD8+ CD45RO+ T cells isolated from AD-H patients was increased, as determined by reverse transcriptase-polymerase chain reaction. Therefore, in AD patients with high IgE levels, type 2 cytokine (IL-4 and IL-13) expression is associated with IgE production, in both CD4+ CD45RO+ T cell and CD8+ CD45RO+ T cell subsets.