ESPE Abstracts

Background: Measurement of salivary glucocorticoids is an accepted method for testing adrenal function and is gaining popularity as it offers a non-invasive collection technique, enabling sampling in the community or home environment, allowing tailored capture of steroid circadian rhythm and improved patient experience. However, there is little data on stability during home collection and sampling methods in young children. Current salivary collection techniques require active patient participation or present a choking hazard and are therefore unsuitable for very young children.

Objectives: To compare salivary glucocorticoids sampled using different collection techniques (Salivette Cortisol, passive drool and SalivaBio); assess the stability of salivary glucocorticoids under different storage conditions replicating home collection; evaluate the time taken for salivary glucocorticoid collection and assess caregiver acceptability when comparing the SalivaBio and a new salivary collection device designed for infants and young children (SalivaBio swab encased in an infant pacifier “SaliPac”).

Methods: Six healthy adults collected salivary samples using a Salivette, passive drool and SalivaBio on retiring for bed, soon after waking and at 3pm for five days. Saliva was stored at 4°C, room temperature and 50°C for 24, 48, 72 hours and a week to replicate potential postage conditions. Salivary cortisol and cortisone concentrations were measured by LCMS. Mean time to collect 1ml saliva and caregiver acceptability using the SalivaBio and SaliPac was assessed in 30 children <6 years in a single-site prospective feasibility study.

Results: There was no significant difference in salivary cortisol and cortisone concentrations using the three different collection methods. Salivary cortisol and cortisone were stable for 72 hours when at room temperature and refrigerated (4oC), with cortisone stable at 4°C and cortisol at room temperature out to a week. High temperature accelerated degradation. Repeated freeze-thaw cycles did not cause significant degradation. In children <6 years the SalivaBio and SaliPac were well tolerated and collected sufficient saliva for salivary steroid analysis in under four minutes. There was no significant difference in time taken for salivary collection between SalivaBio and SaliPac. There was a high level of acceptability in caregivers, who felt confident they could successfully perform salivary collection at home using the SalivBio or SaliPac.

Conclusions: Salivette, passive drool and SalivaBio collect comparable salivary cortisol and cortisone concentrations, which are stable under conditions that replicate home collection and SaliPac is an acceptable device for salivary sampling in young children.