Dual cutaneous reactions to anti-human IgE; no change in plasma level of the split product complement C3d or effect of heparin.

Abstract

The possible dependence of the dual cutaneous reaction (DCR) on activation of the complement and coagulation systems was further elucidated. Heterologous whole anti-human IgE was injected intradermally (i.d.) on the volar aspect of the forearms of 17 drug-free healthy volunteers and venous samples for the selected laboratory test collected from the adjacent cubital vein. Plasma level of C3 split products (C3d) did not change significantly 6 h and 96 h after the injection of anti-IgE inducing immediate cutaneous reactions (ICRs) or DCRs as compared with prechallenge values. Conventional heparin, a compound with anti-coagulant and anti-complementary effects, injected i.d. (200 IE) concomitantly with and by s.c. (1000 IE) infiltration of the whealing 15 and 90 min subsequently to anti-IgE challenge produced no significant inhibition of the resulting ICRs or DCRs. The results suggest that the previously reported involvement of the coagulation process is a secondary phenomenon and do not support the concept that activation of the complement system is necessary for the evolution of DCRs.