New Enzyme Immunoassay for Salivary Cortisol

The measurement of salivary cortisol is emerging as the simplest approach in the diagnosis of Cushing syndrome (1)(2)(3). One of the problems with previous methods is the lack of a Food and Drug Administration (FDA)-cleared method. We have evaluated an enzyme immunoassay (EIA) for salivary cortisol marketed by Salimetrics (State College, PA) and recently cleared by the FDA for in vitro diagnostic use.We compared the new EIA with our modified RIA (2) in 147 samples. The first set of samples (n = 44) was collected at 2300 and 0700 from a group of apparently healthy adult individuals (n = 22; age range, 25–60 years; 11 females and 11 males). The second set of samples (n = 30) was collected at 2300 by patients (n = 30; age range, 12–84 years; 22 females and 8 males) to screen for Cushing syndrome. The third set of samples (n = 73) was collected between 0600 and 1000 from participants (n = 42; age range, 6–14 years; 21 females and 21 males) enrolled in a study of allergic rhinitis. The study was approved by the appropriate Institutional Review Boards, and consent was obtained. Saliva was …