Above mean normal levels of kynurenine, N-acetylkynurenine, hydroxykynurenine, kynurenic acid, and xanthurenic acid were excreted in the urines of 11 patients with discoid lupus erythematosus after loading with 2 gm of L-tryptophan. The levels of the excreted metabolites did not always parallel the extent of the lesions of the skin.
The findings in our control patients were in agreement with the data reported for normal control patients.