Search Results (224)

Intravenous (IV) iron is used to replenish iron stores in patients with iron-deficiency anemia (IDA) who do not benefit from oral iron supplementation. Hypophosphatemia is an increasingly recognized adverse event associated with certain IV iron formulations. Mild/moderate hypophosphatemia may be asymptomatic or present with symptoms similar to those seen in patients with IDA, including fatigue, malaise, and muscle weakness. Persistent hypophosphatemia can cause osteomalacia due to reduced bone mineralization, leading to bone pain and pseudofractures. Ferric carboxymaltose (FCM) can impact phosphate homeostasis through an increase in fibroblast growth factor 23, leading to increased urinary phosphate excretion and hypophosphatemia. In clinical trials, rates of hypophosphatemia were significantly higher in patients receiving FCM compared with other IV iron formulations, such as ferric derisomaltose and ferumoxytol. Treatment guidelines recommend monitoring serum phosphate levels in patients receiving FCM who are at risk for low phosphate or who require repeat infusions, and alternative iron formulations should be considered in at-risk patients. This narrative review summarizes current evidence regarding IV iron-induced hypophosphatemia in individuals with IDA and examines the underlying pathophysiology and clinical evidence for IV iron-induced hypophosphatemia, particularly with FCM, the populations most at risk, and the clinical consequences of persistent hypophosphatemia. Full article

Background/Objectives: Anemia is frequently encountered in emergency departments (EDs). Although intravenous (IV) iron can be used as an alternative or adjunct to red blood cell (RBC) transfusion in selected hemodynamically stable patients, its use in the ED remains limited. This study described IV iron utilization and RBC transfusion patterns in ED patients with anemia and evaluated their associations with clinical outcomes. Methods: We conducted a single-center retrospective cohort study of patients who presented to a tertiary ED with hemoglobin (Hb) ≤ 10 g/dL between January 2019 and December 2021. Patients were categorized according to receipt of IV iron in the ED. Baseline characteristics, laboratory findings, transfusion practice, hospital length of stay (LOS), ICU admission, and in-hospital mortality were compared between groups. Results: Among 3340 patients, 89 (2.7%) received IV iron in the ED. IV iron recipients were older and had lower Hb levels than non-recipients. Gastrointestinal disorders were more frequent in the IV iron group (68.5% vs. 19.9%), and IV iron was commonly administered with ED RBC transfusion. ED transfusion (69.7% vs. 11.1%) and ICU admission (24.7% vs. 15.7%) were more frequent in the IV iron group. Among patients with available ferritin and transferrin saturation (TSAT), IV iron recipients had lower ferritin levels and more frequently showed ferritin-based or combined ferritin/TSAT findings suggestive of iron deficiency. In-hospital mortality was similar between groups (5.6% vs. 5.7%). Among hospitalized patients, median LOS was shorter in the IV iron group than in the non-IV iron group (6.6 vs. 9.7 days). Conclusions: IV iron was infrequently administered in ED patients with Hb ≤ 10 g/dL and was used mainly as an adjunct to RBC transfusion in older patients with gastrointestinal causes of anemia. Its association with shorter LOS should be interpreted cautiously. Structured ED-based anemia evaluation may help optimize IV iron use in selected patients. Full article

Background: Parenteral iron is increasingly used to treat iron deficiency anaemia in patients with gastrointestinal cancer, particularly in the perioperative setting. However, concerns persist that intravenous iron could increase the risk of infection. We conducted a systematic review and meta-analysis to evaluate infectious complications and other relevant clinical outcomes after parenteral iron in gastrointestinal cancer. Methods: Embase, MEDLINE, CENTRAL and Scopus were searched from database inception to 20 February 2026, with additional records identified through citation searching. Comparative studies were eligible if they included adults with gastrointestinal cancer and compared parenteral iron with oral iron, placebo, no iron or standard care. Randomised and non-randomised comparative studies were included. The primary outcome was infection or infective complications. Secondary outcomes included length of hospital stay, hospital readmission and short-term mortality. Risk ratios (RRs) and mean differences (MDs) were pooled using random-effects models. Results: The search identified 2771 records. After removing 458 duplicates, 2313 records were screened, and 210 full texts were assessed. Fourteen comparative studies were included: four randomised controlled trials and ten non-randomised studies. Nine studies contributed to the primary infection analysis, including 899 patients receiving parenteral iron and 768 controls. Infection occurred in 126 patients in the parenteral iron group and 104 controls. Parenteral iron was not associated with an increased risk of infection (RR 1.07, 95% CI 0.71–1.62; p = 0.754; I² = 57%). Restriction to randomised trials also showed no significant increase in infection risk (RR 1.17, 95% CI 0.56–2.43). Thirteen studies reported length of stay, with no meaningful difference between groups (MD: −0.05 days, 95% CI: −0.66 to 0.57). Four studies reported hospital readmission, with no significant difference between parenteral iron and control (RR 0.76, 95% CI 0.35–1.64; p = 0.480; I² = 0%). Mortality analyses were event-limited, with no significant difference in 30-day mortality (RR 0.49, 95% CI 0.09–2.61) or 90-day mortality (RR 0.69, 95% CI 0.35–1.36). Conclusions: In patients with gastrointestinal cancer, parenteral iron was not associated with increased infection risk, prolonged hospital stay, higher readmission or increased short-term mortality. These findings provide reassuring evidence regarding the perioperative safety of parenteral iron, although confidence in the estimate is limited by observational evidence and heterogeneous definitions of infection. Full article

Background/Objectives: Autoimmune gastritis (AIG), celiac disease (CD), and gastric surgery (GS) often cause iron deficiency anemia (IDA) due to iron malabsorption. In this clinical context, IDA treatment is often challenging. The first-line IDA treatment is oral iron supplementation followed by intravenous (IV) iron administration when ineffective or not tolerated. Ferric carboxymaltose (FCM) showed efficacy in various clinical settings. Prospective data evaluating the efficacy of IV FCM in IDA patients secondary to iron malabsorption are scant. The aim of the current study was to assess the tolerability, efficacy, and QoL impact of IV FCM for the treatment of IDA patients with iron malabsorption. Methods: Study design: single-center, prospective observational study: n = 37 adults with AIG, CD, or GS with IDA receiving IV FCM were consecutively included. Endpoints were (i) safety tolerability, (ii) efficacy on IDA recovery (Hb normalization), and (iii) QoL impact. At baseline (T0) and 12 weeks after treatment (T12), a QoL-SF12 questionnaire was assessed. Complete blood count (CBC) and iron status (ferritin, iron, transferrin, transferrin saturation (TS)) were assessed at T0, 4 weeks (T4), and T12 after treatment. Results: Of the 37 IDA patients, 19 (51.4%) had AIG, 9 (24.3%) CD, and 9 (24.3%) GS; Based on Ganzoni’s formula, 24 (64.9%) patients received a single IV FCM infusion (mean ± SEM dosage of 975 ± 12 mg); 13 (35.1%) required two IV infusion sessions with a mean ± SEM cumulative dose of 1400 ± 77 mg. One patient (2.7%) experienced mild adverse events without need for treatment interruption or hospitalization. At T0, anemia was moderate in 7 (18.9%) patients and severe in 1 (2.7%). IDA recovery was achieved in 26 (70.3%) patients at T4 and in 29 (78.4%) at T12. At T4, mean ± SEM Hb increased from 10.8 ± 0.2 g/dL to 12.7 ± 0.1 g/dL, ferritin from 28.5 ± 11.2 ng/mL to 188.2 ± 25.7 ng/mL, and TS from 6.7 ± 0.5% to 23.7 ± 1.9% (p < 0.0001). At T12, mean ± SEM Hb further increased to 13.1 ± 0.2 g/dL (p < 0.05 vs. T4), ferritin slightly decreased to 125 ± 26.7 ng/mL, and TS to 22.7 ± 2.8%. At T12, nonsignificant increases in QoL scores relative to baseline were observed. Conclusions: IV FCM is a safe and effective treatment leading to IDA recovery in nearly 80% of patients at T12. Thus, when oral iron treatment is not feasible or has failed, IV FCM treatment might be considered a first-line therapeutic option for IDA consequent to iron malabsorption. Full article

Background: Postpartum anemia frequently requires packed red blood cell (PRBC) transfusion; however, the contribution of intravenous iron to early hematologic recovery remains uncertain. This study evaluated hemoglobin dynamics following transfusion and the effect of adjunctive intravenous iron therapy. Methods: In this retrospective cohort study, 61 obstetric patients requiring PRBC transfusion were included. Hematologic parameters were assessed at admission, postoperatively, post-transfusion, and at day 7. Patients were stratified according to the administration of intravenous ferric carboxymaltose. Hemoglobin changes and reticulocyte response were analyzed, including a subgroup receiving two PRBC units. Results: Mean hemoglobin decreased from 9.36 ± 1.16 g/dL at admission to 6.33 ± 1.05 g/dL postoperatively, increased to 8.32 ± 0.78 g/dL after transfusion, and reached 8.75 ± 0.97 g/dL at day 7 (p < 0.001). No significant differences between groups were observed before or immediately after transfusion. At day 7, hemoglobin was significantly higher in patients receiving intravenous iron compared with those without supplementation (9.63 ± 1.03 vs. 8.03 ± 0.36 g/dL, p < 0.001). The increase in hemoglobin from post-transfusion to day 7 was greater in the iron group (1.14 ± 0.84 vs. −0.15 ± 0.33 g/dL, p < 0.001), accompanied by a higher reticulocyte response (2.56 ± 0.49% vs. 0.93 ± 0.26%, p < 0.001). Similar findings were observed in the two-unit subgroup. Conclusions: Adjunctive intravenous iron was associated with improved early hemoglobin recovery after transfusion without affecting immediate correction, supporting its clinical use in obstetric patients. Full article

Patient Blood Management (PBM) has evolved from a transfusion-centered practice to a structured, patient-focused perioperative strategy aimed at improving surgical outcomes while preserving blood resources. In the operating room, where bleeding risk is anticipated and modifiable, PBM requires proactive intervention rather than reactive transfusion. This review synthesizes current evidence on perioperative blood conservation strategies specifically relevant to surgeons and anesthesiologists. Preoperative optimization begins with systematic identification and correction of anemia, most commonly iron deficiency, using appropriately timed oral or intravenous iron therapy and, in selected cases, erythropoiesis-stimulating agents. Careful management of anticoagulant and antiplatelet therapies, early recognition of acquired or inherited coagulopathies, and protocol-driven reversal strategies further reduce perioperative hemorrhagic risk. Intraoperatively, blood conservation depends on meticulous surgical technique, respect for anatomical planes, minimally invasive approaches, and the judicious use of advanced energy devices and topical hemostatic agents. Pharmacologic interventions—particularly tranexamic acid administered with appropriate timing and dosing—have demonstrated consistent reductions in blood loss and transfusion requirements across multiple surgical disciplines. Goal-directed coagulation management guided by viscoelastic testing allows targeted correction of specific hemostatic deficits while minimizing unnecessary blood product exposure. Acute normovolemic hemodilution and intraoperative cell salvage provide additional benefit in selected high-blood-loss procedures. Collectively, these multimodal strategies shift perioperative care from product-driven transfusion toward physiology-based blood conservation. When embedded within institutional protocols and supported by multidisciplinary collaboration, perioperative PBM reduces transfusion exposure, decreases morbidity, shortens hospital stay, and promotes sustainable stewardship of blood resources without compromising patient safety. Full article

Background/Objectives: Wolfram syndrome type 1 (WS1) is a rare, progressive, multisystem neurodegenerative disorder characterized by diabetes mellitus, optic atrophy, diabetes insipidus, and sensorineural hearing loss. As survival has improved, an increasing number of affected women are reaching reproductive age. However, evidence on pregnancy and peripartum management in WS1 remains scarce, and practical guidance is limited. This case report describes the multidisciplinary management of pregnancy and delivery in a woman with genetically confirmed WS1 and highlights key considerations for peripartum care. Case Presentation: A woman with genetically confirmed WS1 and long-standing multisystem involvement, including diabetes mellitus, diabetes insipidus, neurogenic bladder requiring frequent self-catheterization, progressive neurologic manifestations, and severe sensory impairment, achieved pregnancy through assisted reproduction with oocyte donation and was closely monitored by a multidisciplinary team. Due to persistent breech presentation, a planned external cephalic version was performed at 37 + 5 weeks’ gestation with immediate availability for cesarean delivery. After unsuccessful attempts, cesarean delivery was performed under combined spinal–epidural anesthesia. Peripartum management focused on strict glycemic control, careful monitoring of fluid balance and urine output, neuraxial anesthesia with proactive hemodynamic management, precautions related to the cochlear implant, and tailored communication strategies. Postpartum recovery was favorable, although anemia on postoperative day 1 required transfusion of one unit of packed red blood cells and intravenous iron therapy. Discussion and Conclusions: Pregnancy in WS1 represents a high-risk clinical scenario because of the coexistence of endocrine, urologic, and neurologic comorbidities, while published evidence on peripartum management remains limited. This case supports an individualized, multidisciplinary approach to obstetric and anesthetic planning and the use of a practical framework to optimize peripartum management and enhance maternal–fetal safety in this rare condition. Full article

Background/Objectives: Higher iron doses are used in the anemia treatment of hemodialysis patients, which allows for lower doses of erythropoiesis-stimulating agents; however, there are concerns regarding the risk of iron toxicity. This study aimed to evaluate the potential toxicity of iron deposition in prevalent hemodialysis patients on iron therapy and its relationship with parameters used to assess iron status, plasma protein oxidation, and cellular iron toxicity. Methods: Magnetic resonance imaging was performed in 56 patients to assess hepatic iron deposition, which was related to clinical and analytical parameters. In patients included in the first and fourth quartiles, according to hepatic iron deposition, plasma protein oxidative stress was quantified, as were iron and cytokine levels in peripheral blood mononuclear cells (PBMCs). Results: Patients with higher hepatic iron deposition had a longer time on hemodialysis (42.0 ± 43.0 vs. 4.9 ± 3.4 months, p < 0.001) and higher ferritin levels (1200 ± 516 vs. 429 ± 278 ng/mL, p < 0.001) than those with lower hepatic iron deposition, without differences in transferrin saturation or hepatic enzyme serum concentration. No differences were found in plasma protein oxidation, iron content, or cytokine mRNA content in PBMCs, except for a decrease in IL-6 levels in patients with higher hepatic iron deposition. Conclusions: Patients with longer hemodialysis times had higher iron stores, suggesting that iron treatment over time increases hepatic iron deposition. No parameters supporting increased toxicity in patients with higher hepatic iron deposition were observed. Full article

Iron oxide particles (magnetite Fe₃O₄, hematite α-Fe₂O₃, and maghemite γ-Fe₂O₃) are prevalent constituents of atmospheric particulate matter (PM) and have gained increasing attention due to potential health implications. This scoping review provides a broad mapping of published in vivo and in vitro studies addressing the biological and toxicological effects of iron oxide particles across particle size fractions (PM10, PM2.5, PM1.0, and nanoscale) and exposure routes, including inhalation, intranasal instillation, and intravenous administration. As a scoping review, no formal risk-of-bias appraisal was conducted; however, studies were selected through predefined eligibility criteria and a structured screening workflow. Iron oxide exposure is consistently associated with oxidative stress and inflammatory responses, while mitochondrial dysfunction, genotoxicity, and neurological effects are frequently reported depending on particle characteristics and exposure context. Among studies with explicit crystalline phase identification, magnetite is most frequently associated with higher biological reactivity, whereas hematite and maghemite display more variable and context-dependent responses. Limited human evidence aligns with experimental findings, identifying magnetite-rich nanoparticles in neural and cardiovascular tissues alongside markers of oxidative and mitochondrial damage. Overall, this scoping review highlights dominant research trends, mechanistic pathways, and key knowledge gaps regarding iron oxide-containing PM, emphasizing the need for integrative approaches linking atmospheric particle characterization with toxicological research. Full article

Background/Objectives: Iron deficiency and associated iron deficiency anaemia represent a major global health burden. Parenteral nutrition (PN) patients are at increased risk of iron deficiency due to inadequate iron supplementation. Currently, iron is added to all-in-one (AIO) PN mostly as low-dose ferric chloride in trace element solutions, limited to 1–2 mg in adults, to ensure emulsion stability and prevent lipid peroxidation. The objective of this study was to evaluate the compatibility and stability of selected, widely used complex-bound iron products added to AIO PN over a 48 h period. Methods: Ferric carboxymaltose and iron sucrose were added as non-biological complex intravenous iron oxide carbohydrate products to two different commercial AIO PN admixtures for adults. The iron concentrations used were 100 and 400 mg/L (1.79 and 7.16 mmol/L), corresponding to approximately 200 mg (3.58 mmol) of iron dose per PN bag. Free and complex-bound iron were separated using 100 kDa dialysis tubes. Free and complex-bound iron were assessed at 4, 24, and 48 h after admixing. pH was measured before and at 0, 4, 24, and 48 h after admixture. Iron quantification was performed by inductively coupled plasma mass spectrometry (ICP-MS). Results: No significant changes in complex-bound iron concentration were observed over the 48 h incubation period (p-value = 0.449; estimate 0.060 mg/L per h, 95% CI −0.089, 0.201 mg/L per h). The concentration of free iron was very low and increased only slightly over time. Iron recovery ranged from 95.8% to 103.9%. The addition of the alkaline iron sucrose significantly increased the pH of the AIO admixture (p-value = 0.033), whereas the addition of ferric carboxymaltose did not affect the pH (p-value = 0.351). After the initial increase, the pH of all conditions remained stable over the 48 h incubation period (p-value = 0.07). Conclusions: Ferric carboxymaltose demonstrated stable intravenous iron admixtures within the PN formulations tested. Before the clinical application of these findings, further studies should specifically evaluate the lipid peroxidation and stability of the lipid emulsions, the most sensitive and important PN compatibility and safety characteristics of AIO PN. Full article

Background/Objectives: Iron-deficiency anemia (IDA) is a common extraintestinal complication of inflammatory bowel disease (IBD). Among high-dose intravenous (IV) iron options, ferric carboxymaltose (FCM) carries a higher risk of treatment-emergent hypophosphatemia than ferric derisomaltose (FDI), with potential clinical consequences. Slovenia’s healthcare setting, characterized by very low IV iron infusion tariffs and recent pricing in which FCM is substantially less expensive than FDI, warrants a setting-specific cost effectiveness evaluation. Methods: We integrated two methodological components: (i) a payer-perspective cost-effectiveness analysis using a patient-level microsimulation model with (ii) an umbrella review of systematic reviews and a targeted search of expert consensus statements on IV-iron-associated hypophosphatemia. Results: In the base case, FDI required fewer infusions than FCM (11.1 vs. 14.2 over 10 years) but generated only €95 in IV iron administration savings due to low tariffs, while drug procurement was €1166 higher with FDI than FCM. When incorporating the clinical impact of hypophosphatemia, incremental quality-adjusted life years (QALYs) were 0.136, yielding an incremental cost-effectiveness ratio (ICER) of €6590/QALY. The umbrella review consistently showed higher hypophosphatemia incidence with FCM (up to 92%) compared with other IV iron formulations (<10%), with recent recommendations emphasizing phosphate monitoring and risk mitigation through alternative formulations. Conclusions: Despite Slovenia’s low IV iron infusion tariffs and lower FCM price, FDI remained cost-effective in this model, largely due to its more favorable hypophosphatemia profile within the model. These findings suggest that hypophosphatemia risk should be considered when selecting IV iron therapy in routine IBD care. Full article

Background and Clinical Significance: Pediatric autoimmune gastritis (AIG) is a rare and frequently underdiagnosed disorder characterized by chronic immune-mediated inflammation and atrophy of the gastric mucosa. In children, AIG typically presents with iron-deficiency anemia (IDA) refractory to oral iron supplementation, in contrast to the pernicious anemia more commonly observed in adults. Diagnosis relies on a combination of serological markers, such as anti-parietal cell antibodies, and histopathological confirmation, with gastric biopsies demonstrating oxyntic mucosal atrophy and lymphocytic infiltration. Early recognition is essential, particularly in patients with personal or familial autoimmune backgrounds, to prevent long-term complications including nutritional deficiencies and increased gastric neoplasia risk. Case Presentation: An 11-year-old boy was referred for evaluation of severe microcytic anemia. He was clinically asymptomatic, with normal growth and physical examination except for mucocutaneous pallor. Celiac disease, thyroid dysfunction, hemoglobinopathies, and infectious or inflammatory gastrointestinal causes were excluded. Despite six months of high-dose oral iron therapy, anemia persisted. Upper gastrointestinal endoscopy showed macroscopically normal mucosa; however, histopathological analysis of gastric body biopsies revealed chronic atrophic gastritis. Serological testing confirmed autoimmune etiology, with positive anti-parietal cell antibodies and hypergastrinemia. Since diagnosis, the patient has required two courses of intravenous iron supplementation, and remains under close follow-up for associated autoimmune and hematologic conditions. Conclusions: Refractory IDA may represent the sole clinical manifestation of AIG in pediatric patients, even in the absence of gastrointestinal symptoms. Histological assessment is crucial, as endoscopic findings may be normal. Early diagnostic suspicion allows timely management focused on correction of nutritional deficiencies and long-term surveillance to mitigate neoplastic risk. AIG should therefore be considered in children with anemia unresponsive to conventional iron therapy. Full article

Background and Clinical Significance: Scurvy, caused by chronic vitamin C deficiency, is re-emerging in Western countries, particularly among pediatric patients with highly selective diets. While its musculoskeletal and mucocutaneous manifestations are well-known, its association with pulmonary arterial hypertension (PAH) is rare and poorly understood. Ascorbic acid and iron are essential cofactors for prolyl hydroxylases (PHD), which regulate Hypoxia-Inducible Factors. Their combined deficiency may trigger a “pseudohypoxic” state, leading to pulmonary vascular remodeling and vasoconstriction. Case Presentation: A 30-month-old female presented with a one-month history of limping, lower limb pain, and gingival hypertrophy. Dietary history revealed an almost exclusive cow’s milk-based intake. Physical examination showed diffuse petechiae, pallor, and right knee edema. Laboratory findings confirmed scurvy (undetectable vitamin C), severe iron-deficiency anemia (Hb: 72 g/L; ferritin: 22 mcg/L; RDW: 30%), folate deficiency, and hyperhomocysteinemia. Notably, elevated copper and vitamin B12 levels suggested a state of metabolic dysregulation. Echocardiography revealed moderate PAH phenotype (estimated sPAP: 47–50 mmHg) and a hyperdynamic contractility. A “perfect storm” mechanism was hypothesized, involving iron–ascorbate-dependent PHD impairment, high-output state, and oxidative-stress-induced hepcidin dysregulation (suggested by elevated copper). Following intravenous vitamin C and multivitamin supplementation, pulmonary pressures normalized within one week. Conclusions: PAH phenotype in scurvy represents a reversible metabolic disruption of pulmonary vascular tone rather than a structural disease. This case underscores the synergistic role of vitamin C, iron, and folate in vascular homeostasis. Clinicians should maintain high suspicion for scurvy in children with selective diets and unexplained PAH, as nutritional restoration is curative. Full article

Cadmium (Cd) is a ubiquitous environmental pollutant that enters the circulation from the lungs and gastrointestinal tract. For most people, staple foods form the main route of Cd exposure. Current evidence suggests that Cd may increase the prevalence of iron deficiency and anemia in environmentally exposed people. Concerningly, intravenous iron administration to treat iron deficiency anemia has resulted in adverse bone outcomes at a higher-than-expected frequency, for which reasons remain unclear. The bone-derived hormone fibroblast growth factor 23 (FGF23), the regulator of vitamin D and phosphate homeostasis, has been speculated to be implicated, given that anemia, iron deficiency and inflammatory conditions are all known to increase FGF23 expression levels in osteoblasts. Additionally, early studies have demonstrated that Cd increases FGF23 expression by osteoblast-like cells and suppresses FGF23 cleavage, leading to an abrupt rise in serum FGF23, which, in turn, mediates an effect of Cd on tubular phosphate reabsorption. In this review, experimental breakthrough studies showing Cd-induced iron deficiency and a reduction in iron absorption by Cd are summarized, together with intestinal absorption of Cd and an increment in Cd uptake and Cd body burden in those with low body iron stores. Potential contributions of Cd, anemia and iron deficiency in the context of hypophosphatemic osteomalacia development after intravenous iron supplementation are discussed. The molecular basis of Cd-induced ferroptosis in pathogenesis of osteoporosis, emphasizing heme oxygenase-1 (HO-1)/bilirubin axis and zinc deficiency, is presented. Full article

Background/Objectives: In Japan, cancer-related anemia (CRA) is common, and erythropoiesis-stimulating agents (ESAs) are not approved for chemotherapy-induced anemia. Modern intravenous (IV) iron formulations, such as ferric carboxymaltose (FCM) and ferric derisomaltose (FDI), enable high-dose repletion; however, real-world evidence in ESA-free oncology settings remains limited. Methods: This single-center retrospective study included patients with CRA (N = 55) who received high-dose IV iron (FCM or FDI). Iron phenotypes were classified as absolute iron deficiency (ID), functional ID, or non-ID. The primary endpoint was hemoglobin (Hb) change from baseline to approximately 1 month (21–45 days) in the non-transfused patients. Secondary endpoints included responder rate (ΔHb ≥ 1.0 g/dL), transfusion avoidance rate, dosing adequacy relative to Ganzoni-calculated iron deficit, and safety, particularly hypophosphatemia. Results: Among the non-transfused patients, mean Hb increased from 8.76 ± 1.34 g/dL to 9.73 ± 1.75 g/dL (mean ΔHb +0.92 ± 1.44 g/dL; p < 0.001). The responder and transfusion avoidance rates were 48.9% and 81.8%, respectively. Functional ID was most prevalent (52.7%), with clinically meaningful Hb responses. A total of 38.2% achieved approximately 1000 mg dosing. The safety profile was excellent, and no infusion reactions or symptomatic hypophosphatemia was observed (median serum phosphate changed from 3.4 [3.0–3.9] to 3.2 [2.7–3.8] mg/dL). Conclusions: In this real-world Japanese oncology setting where ESAs were not available for chemotherapy-induced anemia, high-dose IV iron monotherapy (FCM or FDI) was well tolerated and was associated with modest short-term Hb increases and a high observed rate of transfusion avoidance within a 21–45-day assessment window. These findings suggest that a proactive, TSAT-guided IV iron therapy approach may be a pragmatic option for selected patients; however, durability beyond 1 month, optimal re-dosing, and generalizability require confirmation in larger, longer prospective studies. Full article