Inhibition of mitogenic lectin induced blast transformation in human peripheral blood mononuclear cells by mefloquine.

The effect of mefloquine-HCL, a new 4-quinoline methanol anti-malarial compound, on in vitro blast transformation of human peripheral blood mononuclear cells (MNC) was studied. Mefloquine significantly suppressed lectin-induced blast transformation of MNC from healthy Thai adults but MNC responsiveness in the mixed leucocyte reaction (MLR) and cellular viability were not reduced by the concentrations of mefloquine studied. Both T and non-T MNC responsiveness was lower in cultures containing the drug than in normal control cultures. The addition of serum from individuals on mefloquine chemoprophylaxis caused no significant suppression in the blast transformation assays or the MLR but the data do not rule out any clinically significant in vivo suppressive effect by mefloquine on human cellular immune response.