The effect of anti-reactional drugs on complement components in the type II, erythema nodosum leprosum, reaction.

Seventeen patients with the type II (erythema nodosum leprosum) (ENL) reaction were studied. They received multidrug therapy and also the anti-reactional drugs prednisolone clofazimine or chloroquin, and we measured serum levels of complement components before treatment and after the reaction had subsided. Factor B was significantly elevated after treatment with each of the three drugs. C3 levels were significantly increased after treatment, the largest change being in patients treated with clofazimine. In these patients there was also a concomitant decrease in C3d levels. This suggests that clofazimine has complement modulating activity and we would recommend it as the drug of choice in treatment of the ENL reaction.