92 Serum CTLA-4 AND IL-10 in Hymenoptera Venom Immunotherapy: Equivalence of Different Induction Regimens

BACKGROUND: Cytotoxic T lymphocyte associated gene-4 (CTLA-4) is involved in the activation pathways of T lymphocytes. It has been shown that the circulating form of CTLA-4 is elevated in patients with hymenoptera allergy and can be downregulated by immunotherapy. We assessed the effects on CTLA4 of venom immunotherapy given by different induction protocols (classic, rush or ultra rush). METHODS: Sera from patients with hymenoptera allergy were collected at baseline and at the end of the induction phase. In the classical regimen, the induction lasted 6 weeks, in the rush protocol it lasted 3 days, and in the ultra-rush maintenance was achieved in 24 hours. Soluble IL-10 was assayed in the same samples for comparison. CTLA-4 and IL10 were measured by commercial immuoassays. RESULTS: Seventy-six patients (52 male, mean age 35 years) were studied. Of them, 30 underwent the classic induction, 22 the rush and 24 the ultra rush. Soluble CTLA-4 was detectable in all patients at baseline, and significantly decreased at the end of the induction in all groups, thus irrespective of its duration. Of note, a significant decrease of sCTLA-4 could be seen already at 24 hours. In parallel, the same behaviour was observed with IL-10 that significantly increased at the end of the induction. CONCLUSIONS: Soluble CTLA-4 is a useful immunological marker of the effect of immunotherapy for hymenoptera allergy. From an immunologic point of view, there is no difference among the various protocol of induction.