IFNG and sarcoidosis: T-helper-type-1 (Th1) immune responses to C. acnes catalase (KAT) have been measured by interferon (IFN-γ) assay in the peripheral blood mononuclear cells from 12 sarcoidosis patients, 13 patients with other pneumonitis, and 11 healthy volunteers; the KAT protein provoked a significantly higher response in patients with sarcoidosis [34].