Increased serum iron levels and infectious complications after liver transplantation

Abstract

Background: Elevated serum iron levels have been associated with infectious outcomes in various patient populations but, to our knowledge, have never been studied after liver transplantation.

Methods: The relationship between serum iron levels and infectious outcomes after liver transplantation was evaluated in a nested case-control study using prospectively collected data and serum samples. Unadjusted and adjusted hazard ratios were calculated for each iron marker predictor variable (iron level, unsaturated iron-binding capacity, total iron-binding capacity, transferrin saturation, and ferritin level) and time to development of each of 6 outcomes (cytomegalovirus [CMV] disease, invasive fungal infection, bacteremia, invasive fungal infection or bacteremia, any infection, and 1-year mortality rate).

Results: Serum measurements (n = 109) corresponding to increased levels of serum iron were independently associated with an increased risk of any infection and death. After adjusting for the number of red blood cell transfusions, donor CMV-seropositive status, and fungal colonization, ferritin level was independently associated with the development of any infection (hazard ratio, 1.09; 95% confidence interval, 1.04-1.14). After adjusting for the number of red blood cell transfusions, development of CMV disease, and administration of intravenous steroids for treatment of rejection, ferritin level was also was independently associated with death (hazard ratio, 1.11; 95% confidence interval, 1.04-1.18). Similar results were found for unsaturated iron binding capacity for the same 2 outcomes.

Conclusions: A better understanding of iron metabolism and its relationship to infection could help guide future infection prognosis, prevention, and management efforts in this high-risk population.