Recombinant interleukin-1 alpha augments granuloma formation and cytokine production but not parasite clearance in mice infected with Leishmania donovani.

In vivo administration of various doses of recombinant interleukin-1 alpha to B10.D2/n mice chronically infected with Leishmania donovani resulted in enhanced formation of granulomas and in vitro production of gamma interferon. By direct microscopical enumeration, reduction in gross parasite burden in the viscera was not observed, however. These data highlight an important discordance between granuloma formation per se and parasite elimination and suggest that interleukin-1 deficiency alone cannot account for the chronicity of this disease.