The effect of oxisuran on human immunological responsiveness

Immunological function was evaluated in 9 patients who received oxisuran at a dose range of 5-90 mg/kg, for periods of 5-40 weeks. Bone marrow cytotoxicity and lymphopenia did not occur. Established humoral immunological reactions were unaffected by oxisuran. Only 6 of 19 previously positive skin tests reverted to negative. Primary cellular immune reactivity was markedly suppressed. Allogenic skin graft survival was prolonged to a mean of 30.7 days and only 2 of 9 patients were successfully sensitized to dinitrochlorobenzene and Keyhole limpet hemocyanin, respectively. Both IgG and IgM responses to primary typhoid immunization were inhibited. In vitro peripheral blood lymphocyte activity in phytohemagglutinin and mixed lymphocyte culture tests remained normal. These data suggest that oxisuran interferes with the afferent limb of the immune system and may thereby be clinically useful in human transplantation.