[Analysis of immunosuppressive activity of lecithin-bound iodine (LBI) on antigen-induced IL2 responsiveness in peripheral blood lymphocytes from patients with allergic diseases].

The effect of lecithin-bound iodine (LBI) on antigen-induced IL2 responsiveness, useful in in vitro test for the detection of etiological antigen and disease activity in allergic diseases, was investigated. In peripheral blood mononuclear cells (PBMC) from asthmatic children, LBI suppressed Dermatophagoides farinae (Df)-induced IL2 responsiveness in a dose dependent manner, in a range of 0.01 to 100 micrograms/ml. Similarly, LBI also suppressed ovalbumin (OVA)-induced IL2 responsiveness in PBMC from patients with atopic dermatitis, sensitized with OVA, in concentration of 0.1 to 100 micrograms/ml. Moreover, purified protein derivative (PPD)-induced IL2 responsiveness was equally inhibited by LBI, at doses of between 0.1 and 100 micrograms/ml. However, LBI could not overcome the responses induced by concanavalin A (Con A) until it reached unphysiological concentrations of as high as 100 micrograms/ml. The fact that antigen-induced IL2 responsiveness was suppressed by LBI at concentrations comparable to blood levels of LBI in individuals medicated suggests that LBI is a weak immunosuppressant. IL2-responding T cells were more sensitive to LBI than antigen-presenting cells in Df-induced IL2 responsiveness, although LBI suppressed both cell populations. Taken together, LBI could work as a weak immunosuppressant to inhibit lymphocyte responses to allergen and to improve clinical status in allergic diseases, including bronchial asthma caused by Df and atopic dermatitis provoked by OVA.