Impact of pretransplant serum ferritin level on risk of invasive mold infection after allogeneic hematopoietic stem cell transplantation

Invasive mold infections (IMI) are life-threatening complications of allogeneic hematopoietic stem cell transplantation (HSCT) and are mostly caused by Aspergillus species and Mucorales. We examined whether elevated serum ferritin prior to HSCT was associated with increased risk of IMI after allogeneic HSCT. Elevated serum ferritin was defined as values ≥ 1000 ng/mL. Pretransplant ferritin levels were available for 477 transplants. Nine developed IMI at day 30 and 21 had IMI at day 100 for a cumulative incidence of 1.9% and 4.4%, respectively. Among the high ferritin group, eight of 220 transplant cases (3.6%) developed an IMI within 30 d after HSCT compared with one of 257 (0.4%) in the low ferritin group (P = 0.01). Fourteen of 220 (6.4%) and seven of 257 transplant cases (2.7%) in the high and low ferritin groups, respectively, had developed an IMI by day 100 after HSCT (P = 0.07). Nine of 53 (17%) patients with grades III and IV acute GVHD and iron overload experienced IMI, when compared to three of 37 (8.1%) with high-grade aGVHD, but no iron overload. Among patients without aGVHD, those with elevated ferritin had a 2.7% incidence of IMI compared with 0.9% for patients without elevated ferritin. There was a marginally significant difference in cumulative incidence function between high and low ferritin groups for IMI (P = 0.06). However, elevated serum ferritin (≥ 1000 ng/mL) was not a significant risk factor for IMI in a multivariate competing risk regression model after adjusting for aGVHD.