Effect of specific immunotherapy on serum levels of tumor necrosis factor alpha in asthmatic children.

There is no general agreement among investigators regarding the effect of specific immunotherapy (SIT) on T-cell reactivity. The aim of this study was to investigate the serum levels of IL-1beta, IL-6, and TNF-alpha of children with allergic asthma before and after 3 and 12 months of SIT. Additionally, after 12 months of SIT, we investigated the bronchial hyperresponsiveness. The secondary end points were clinical parameters. Thirty-two children with moderate asthma allergic to house-dust mites (study group) and 10 healthy children (control group) participated in this trial. At each visit blood samples were drawn from all asthmatic patients and at the prestudy visit in controls for determination of parameters. All asthmatic patients received SIT. At the second study visit, baseline spirometry and methacholine challenge tests were performed. Serum TNF-alpha during SIT tended to increase after 3 months with respect to baseline, whereas after 12 months of SIT, serum TNF-alpha decreased. The correlation coefficient (r) between the changes in TNF-alpha values between 3 and 12 months of SIT and provocative concentrations of methacholine to cause a 20% fall in FEV(1) (PC20M) after 12 months of SIT was positive (r = 0.76; p < 0.0001); the greater the changes in TNF-alpha level, the higher the PC20. No modification of IL-1beta and IL-6 was observed. Clinical symptoms also improved after 12 months of SIT in children with asthma. In summary, our results showed the variations in serum levels of TNF-alpha during SIT in asthmatic children and confirm anti-inflammatory properties of SIT.