R.M. Silver, M.P. Heyes, J.C. Maize, B. Quearry, et al., "Scleroderma, fasciitis, and eosinophilia associated with the ingestion of tryptophan," New England Journal of Medicine, 322:874-81, 1990.
Richard M. Silver (Medical University of South Carolina, Charleston): "We described the clinical and histopathological findings in nine patients who developed what is now known as the eosinophilia-myalgia syndrome (EMS) associated with ingestion of L-tryptophan, comparing and contrasting them to other fibrosing conditions, such as scleroderma and eosinophilic fasciitis. In addition, we demonstrated for the first time that EMS patients have an alteration of L-tryptophan metabolism during the active phase of the illness.
"The altered metabolism of L-tryptophan appears to result from the induction of an enzyme, indoleamine- 2,3-dioxygenase. The altered metabolism is not due to an inborn error; it is likely due to induction of the enzyme by inflammatory mediators, such as interferon-gamma, since normal metabolism occurs after steroid treatment or spontaneous ...
