A Validation Study of Transferrin and I-FABP As Dried Blood Spot-Based Biomarkers of Environmental Enteric Dysfunction

Environmental Enteric Dysfunction (EED) is a subclinical condition characterized by increased intestinal permeability and impaired nutrient absorption, but current methods for assessing EED are invasive and resource intensive. Dried blood spot (DBS) biomarker sampling offers a minimally invasive method of detecting EED. We present a validation study of two DBS protocols for the measurement of transferrin, a biomarker of iron status, and I-FABP, a biomarker of intestinal permeability. Matched DBS from a fingerstick and venous whole blood samples from n=74 individuals were collected over a 3-week period. Whole blood was used to create additional DBS samples and then spun down to plasma for analysis. We found a weak linear association between plasma and DBS measurements of transferrin concentrations, but a strong linear association and high level of agreement between plasma and DBS measurements of I-FABP concentrations. These findings demonstrate the validity and feasibility of measuring I-FABP, but not transferrin, using DBS sampling.