Effect of heart-lung transplantation on airway potential difference in patients with and without cystic fibrosis

Abstract

Measurement of the potential difference (PD) across the airways provides an indication of the viability and integrity of the lining epithelium. PD was recorded from the lower airways in "diseased controls" and in patients following heart-lung transplantation. Diseased controls showed a high PD centrally which fell (became less negative) peripherally (trachea -15.8 mV (SEM 1.0), lobar bronchi -12.6 mV (1.2), segmental bronchi -9.8 mV (1.2]. Following heart-lung transplantation (HLT) the profile of PD with airway size was altered in comparison to non-transplanted patients with reduced values in the large airways. Host tracheal values above the anastomosis were similarly reduced. Two episodes of rejection were associated with a lower mean airway PD; no significant changes were found with infection. In patients with cystic fibrosis (CF), values in the donor lung did not differ from those in non-CF transplanted patients up to one year following transplantation, although nasal PD in the host remained elevated. HLT selectively alters the PD profile only of larger airways, which may relate to the interruption of the bronchial arterial supply to these sites.