Chemical inactivation of the Kveim reagent.

In an attempt to identify the nature of the active principle, Kveim reagent was exposed to chemical fractionating agents. Thirty-one patients with sarcoidosis underwent simultaneous intradermal injection with fractionated and unfractionated Kveim material. Kveim reagent was stable in the presence of DNAse, RNAse, pronase, 95% phenol, neutral detergent, and to lipid extraction with chloroform-methanol. Kveim reagent was also stable in the presence of both 8 M urea (8MU) and 2-mercaptoethanol (2ME) when used alone. When both these agents were used together, Kveim reagent was inactivated. Fourteen patients had a positive test to unfractionated Kveim reagent; of these, only 2 gave a positive response to material fractionated by exposure to 8MU and 2ME. Simultaneous exposure to 8MU and 2ME was more likely to inactivate Kveim reagent (10/10 tests) than sequential exposure to 8MU and 2ME (2/4 tests). Chemical analysis of the fractionated material showed that it retained granuloma-generating activity despite the lack of carbohydrates. Protein loss in terms of total and relative amino acid composition was progressive and non-specific throughout processing. These results are consistent with a protein-active principle which is dependent on three-dimensional structure.