Serum Hepcidin Antimicrobial Peptide Levels Predict Infection After Lung Transplantation

Differentiation of infection from allograft rejection is challenging after lung transplantation (LT). Iron metabolism and the innate immune system are interwoven processes; further, Hepcidin (HEP) is a predominantly hepatic-derived, homeostatic regulator of enterocyte Fe++ absorption and macrophage "recycling" via Ferroportin. Transcription of HEP is induced by cytokines IL-6, IL-1, IL-22, Toll-like receptors-4&5 and the JAK-STAT 3 pathway. Herein we investigate the utility of HEP serum determination for "surveillance" after LT. Interim analysis of a prospective, IRB approved, single- center, "surveillance study" of serum HEP determination concurrent with FOB assessments post-LT . Measurement of serum HEP by ELISA [Intrinsic LifeSciences, Inc.; La Jolla, CA] is correlated with allograft related "events" depicted as: Infxn, ACR, BOS, NORMAL (1 month post-LT). Interim preliminary data suggest serum HEP levels correlate most strongly with presence of allograft Infxn with a "trend" for increase during ACR, however NOT increased with either BOS or "Quiescence" within the allograft. Two episodes of ALI / DAD with negative BAL cultures also associated with increased HEP. HEP serum levels predict presence of Infxn and "quiescence" after LT while prospective long-term data is forthcoming with larger "N" which is required for this assessment during ACR and BOS.