Actigraph Measurements of Nursing Home Residents in TURN Study

Background: Studies with longitudinal and/or time-series designs would benefit from non-invasive methods to assess immune response. Immune response levels typically are measured with blood obtained by venipuncture, which is distressing to subjects and, thus, may adversely affect recruitment and retention of subjects in studies with multiple or repeated biological sampling. Aims: The study aims were to partially validate commercially available enzyme immunoassays (EIA) for interleukin (IL)-6 and tumor necrosis factor – alpha (TNF-α) in saliva. Methods: We performed spike and recovery experiments at seven dilutions and correlated levels of IL6 and TNF-α in saliva and plasma from 20 healthy adult volunteers (6 male and 14 female). All assays were done by the same technician with a microtitration plate reader, using wavelength correction and EIA products from a single vendor. Results: Spike and recovery performances were as follows: Salivary IL-6 – intra-assay percentage coefficient of variation (CV), 8.4%; sensitivity, 0.11 pg/mL; mean recoveries, 81% in spiked saliva and 110% in spiked controls; and linearity, r = .995; salivary TNF-α – intra-assay CV, 10.8%; sensitivity, 2.3 pg/mL; mean recoveries, 44% in spiked saliva and 92% in spiked controls; and linearity, r = .950. The correlation between IL-6 in saliva and plasma was r = .472 (p = .04); the correlation between TNF-α in saliva and plasma was r = .039 (p = .88). Conclusions: Spike and recovery and linearity performance was adequate for salivary IL-6, but not for salivary TNF-α. Whereas salivary IL-6 was modestly and significantly correlated with plasma IL-6 in healthy adult volunteers, salivary and plasma TNF-α were weakly and insignificantly related. Saliva may be used as an alternative matrix to plasma with EIA to measure IL-6, but not TNF-α. Use of noninvasive IL-6 to assess immune response will benefit longitudinal studies and those with timeseries designs. Grant Support: Vivian L. Smith Foundation and Jerold B. Katz Foundation Endowment for Nursing Research RESEARCH DAY 2015 ABSTRACTS OF PRESENTATIONS The Experience of Family Members of ICU Patients Who Require Extensive Monitoring: A Qualitative Study Claudia D. Smith, Kristi Custard