Immunological effects of thalidomide. Inactivity of the drug and several of its hydrolysis products in mononucleocyte proliferation tests.

In order to study the spontaneous degradation of thalidomide (N-phthalyl-glutamic acid imide), an HPLC method for the separation of the drug and its hydrolysis products was developed. The effect of these substances upon the proliferation of lectin- and allogeneically stimulated peripheral blood mononucleocytes was studied, using the incorporation of [3H]-thymidine as a marker. In contrast to optically evaluated experiments reported earlier, no inhibition of [3H] incorporation was found, regardless of the duration, mode, or timing of stimulation.