Elevated Extracellular Levels of Granzymes in Patients with Scrub Typhus

Scrub typhus is an acute febrile disease caused by Orientia tsutsugamushi, which is transmitted through chigger mites. Delayed treatment results in various complications and, in severe cases, death. Granzymes are secreted by cytotoxic T lymphocytes or natural killer cells and are known to play an important role in controlling intracellular pathogens. To date, few studies have been done on granzymes in patients with scrub typhus. In this study, granzymes A and B showed a significant increase during the acute stage of scrub typhus compared with healthy control subjects, and decreased sharply after treatment. In addition, granzymes A and B were significantly high in the moderately elevated liver enzyme group. In conclusion, it appears that the host during the acute phase of scrub typhus increases cytotoxic T-cell activity to control infection.