Selectively increased adenosine deaminase levels in T cells during typhoid fever.

ADA and PNP levels were measured in T-enriched and T-depleted subpopulations of peripheral mononuclear cells from patients with typhoid fever. ADA activity was significantly increased in T-enriched, but normal in T-depleted preparations of typhoid patients. Elevated levels of ADA in T cells were observed from the initial phase up to 30 days from the onset of the disease. Unlike ADA changes, PNP modifications were transitory, and affected both T-enriched and T-depleted subpopulations. The usefulness of ADA determination in T cells to detect and follow up T-cell activation during typhoid fever is suggested.