The use of intravenous (IV) iron for the treatment of iron deficiency anemia (IDA) during acute infections remains controversial, largely due to concerns that iron supplementation may worsen infectious outcomes.¹ Prior studies have reported conflicting results, contributing to ongoing hesitancy among clinicians to administer IV iron during active infection.¹ At the ASH Annual Meeting & Exposition 2025, Dr. Haris Sohail from the Charleston Area Medical Center in the United States, presented findings from a large real-world analysis evaluating the association between IV iron administration during hospitalization for acute infections and clinical outcomes, including survival rate, hemoglobin response, and hospital utilization metrics.¹

This retrospective cohort study utilized the TriNetX Research Network to identify adult patients (≥18 years) hospitalized between 2000 and 2024 with a diagnosis of IDA and one of the following acute infections: methicillin-resistant Staphylococcus aureus (MRSA) bacteremia, pneumonia, urinary tract infection (UTI), colitis, cellulitis, or bacterial meningitis.¹ To ensure active infection management, patients were required to have received antibiotic therapy within two days of infection diagnosis.¹ Patients were stratified based on receipt of IV iron during or near the active course of illness.¹ Propensity score matching (1:1) was performed within each infection subgroup to balance age, sex, race, baseline laboratory values, and relevant comorbidities.¹ All analyses were conducted within the TriNetX platform using built-in survival and risk assessment tools.¹

Among 8,433 propensity-matched patients in each group hospitalized with MRSA bacteremia, IV iron administration was associated with significantly lower mortality at both 14 days (early survival) (HR=0.48; 95% CI: 0.41-0.57; p<0.0001) and 90 days (HR=0.67; 95% CI: 0.62-0.73; p<0.0001).¹ Similarly, in a cohort of 19,281 patients in each group hospitalized with pneumonia, IV iron use was associated with reduced mortality at 14 days (HR=0.50; 95% CI: 0.46-0.54; p<0.0001) and at 90 days (HR=0.66; 95% CI: 0.63-0.69; p<0.0001).¹

Consistent mortality reductions were also observed across other infection subtypes.¹ In 18,613 patients in each group hospitalized with UTIs, IV iron administration was associated with lower mortality at 14 days (HR=0.56; 95% CI: 0.49-0.63; p<0.0001) and 90 days (HR=0.73; 95% CI: 0.69-0.78; p<0.0001).¹ Among 4,432 patients in each group with colitis, IV iron use was associated with reduced mortality at 14 days (HR=0.52; 95% CI: 0.41-0.66; p<0.0001) and 90 days (HR=0.60; 95% CI: 0.53-0.68; p<0.0001).¹ In 8,404 patients per treatment group hospitalized with cellulitis, IV iron administration was associated with lower 14-day mortality (HR=0.55; 95% CI: 0.44-0.68; p<0.0001) and 90-day mortality (HR=0.70; 95% CI: 0.63-0.78; p<0.0001).¹ In contrast, exploratory analysis among the smaller cohort hospitalized with bacterial meningitis determined that IV iron use was not associated with a statistically significant difference in mortality at 90 days (HR=0.94; 95% CI: 0.52-1.69; p=0.83).¹

Hemoglobin response was evaluated at both 14-day and 60-90 days after treatment.¹ Across all infection subgroups except meningitis, IV iron administration was linked to greater improvements in hemoglobin levels, with the magnitude of increase consistently exceeding +1.2g/dL compared with no IV iron, at only +0.7g/dL to +1.0g/dL.¹ Patients with colitis demonstrated the greatest hemoglobin increase with IV iron, with nearly double the hemoglobin rise compared with no IV iron (+1.45g/dL vs. 0.74g/dL).¹

In conclusion, this large real-world analysis demonstrated that IV iron administration during hospitalization for acute infection was safe, with no evidence of harm across infection types in patients with IDA.¹ IV iron use was associated with improved short- and long-term survival and greater hemoglobin improvement across multiple infection subtypes.¹ Reduced transfusion requirements were also observed, with the largest difference reported in patients with colitis.¹ Given the retrospective nature of this analysis, prospective trials are warranted to confirm these findings.¹