Immunotherapy with levamisole: early decrease of cAMP levels in lymphocytes from treated cancer patients.

Lymphocyte cyclic nucleotide content was studied before and after Levamisole administration to cancer patients. Twelve patients with disseminated cancer received 100 mg/m2 on two consecutive days; nine comparable patients with disseminated cancer served as controls. Endogenous cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) were measured in lymphocytes before, 24, and 48 hours after ingestion of the first dose of Levamisole. A statistically significant decline in lymphocyte cAMP level was observed after drug administration and no significant changes were noted in cGMP levels. Further studies will be necessary to correlate this biochemical change in cyclic nucleotides with modulation of the functional level of cellular immune mechanisms.