Résumé
The cytokine cascade involved in IgE production has implications in allergic inflammation. For this purpose, changes in IL-6 and IgE levels and eosinophilic count were evaluated in sixty children with atopy. They included thirty patients with atopic dermatitis [AD], and thirty with bronchial asthma [BA]. Twenty age- matched apparently healthy children were chosen as control group. The mean serum IL-6 Level was significantly higher in AD [18.85 +/- 17.79 Pg/ml] and BA [45 +/- 38.79 Pg/ml] than the control group [10.28 +/- 7.02 Pg/ml], [p<0.01 and <0.001 respectively]. Higher values for IgE and eosinophil count were also demonstrated among AD [681.9 +/- 555.79 Iu/ml] and [0.69 +/- 0.5 count x 10[2]/L] and BA [2122.9 +/- 1636.86 Iu/ml] and [0.52 +/- 0.38 count x 10[2]/L] as compared to controls [75 +/- 23.8 Iu/ml] and [0.15 +/- 0.11 count x 10[2]/L], [P<0.001 for both]. In addition, serum IL-6 and IgE values were significantly higher in BA than AD group [P<0.01 and <0.001 respectively]. Correlation studies revealed a highly significant positive correlation between serum IL-6 and IgE in both AD [r = 0.79] and BA [r = 0.76] groups, [P<0.001 for both]. Furthermore, among AD group, IL-6 and IgE levels differed grossly with the degree of severity of the disease. By using Z-score, IgE level was the most sensitive estimated parameter to discriminate AD and BA from control group. IL-6 was the second one in BA, while eosinophilic count was the second discriminative parameter in AD. We concluded that IL-6 may be used a sensitive marker of disease activity, beside its possible role in the pathophysiology of bronchial asthma and atopic dermatitis