Iron overload: the Achilles heel of β- thalassemia

Systematic transfusions coupled with iron chelation therapy have substantially improved the life expectancy of thalassemia patients in developed nations. As the human organism does not have a protective mechanism to remove excess iron, iron overload is a significant concern in thalassemia, leading to organ damage, especially in the heart and liver. Thus, iron chelation therapy is crucial to prevent or reverse organ iron overload. There are three widely used iron chelators, either as monotherapy or in combination. The choice of iron chelator depends on several factors, including local guidelines, drug availability, and the individual clinical scenario. Despite treatment advancements, challenges persist, especially in resource-limited settings, highlighting the need for improved global healthcare access. This review discusses clinical management, current treatments, and future directions for thalassemia, focusing on iron overload and its complications. Furthermore, it underscores the progress in transforming thalassemia into a manageable chronic condition and the potential of novel therapies to further enhance patient outcomes.

Lifetime Transfusion Burden and Transfusion-Related Iron Overload in Adult Survivors of Solid Malignancies

BACKGROUND

Limited data exist on transfusion burden and transfusion-related iron overload in adult survivors of solid malignancies.

METHODS

Hospital-specific cancer registry data of patients with solid tumor receiving systemic anticancer treatment between January 2008 and September 2009 at the Oncology Department of the Leiden University Medical Center (The Netherlands) were retrieved and cross-referenced with red blood cell (RBC) transfusion records. Individual lifetime transfusion burden was captured in April 2015. Multitransfused long-term survivors with serum ferritin >500 μg/L were subsequently screened for hepatic and cardiac iron overload using 1.5 Tesla magnetic resonance imaging.

RESULTS

The study population consisted of 775 adult patients with solid cancer (45.2% male; median age, 58 years; >75% chemotherapy-treated), 423 (54.6%) of whom were transfused with a median of 6.0 RBC units (range 1-67). Transfusion triggers were symptomatic anemia or hemoglobin <8.1-8.9 g/dL prior to each myelosuppressive chemotherapy cycle. We identified 123 (15.9%) patients across all tumor types with a lifetime transfusion burden of ≥10 RBC units. In the absence of a hemovigilance program, none of these multitransfused patients was screened for iron overload despite a median survival of 4.6 years. In 2015 at disclosure of transfusion burden, 26 multitransfused patients were alive. Six (23.1%) had hepatic iron overload: 3.9-11.2 mg Fe/g dry weight. No cardiac iron depositions were found.

CONCLUSION

Patients with solid malignancies are at risk for multitransfusion and iron overload even when adhering to restrictive RBC transfusion policies. With improved long-term cancer survivorship, increased awareness of iatrogenic side effects of supportive therapy and development of evidence-based guidelines are essential.

IMPLICATIONS FOR PRACTICE

In the presence of a restrictive transfusion policy, ∼30% of transfused adult patients with solid cancer are multitransfused and ∼50% become long-term survivors, underscoring the need for evidence-based guidelines for the detection and management of transfusion-related iron overload in this group of patients. In each institution, a hemovigilance program should be implemented that captures the lifetime cumulative transfusion burden in all patients with cancer, irrespective of tumor type. This instrument will allow timely assessment and treatment of iron overload in cancer survivors, thus preventing organ dysfunction and decreased quality of life.

Assessment of liver and cardiac iron overload using MRI in patients with chronic anemias in Latin American countries: results from ASIMILA study

OBJECTIVES

A multicenter, noninterventional, observational study was conducted in the Latin American countries including Argentina, Brazil, Colombia, Mexico, and Venezuela to assess the prevalence of liver and cardiac iron overload using magnetic resonance imaging (MRI) in patients with chronic anemias except thalassemia.

METHODS

Patients aged >10 years with transfusion-dependent anemias, except thalassemia, either with <20 units of red blood cell (RBC) transfusions with serum ferritin (SF) levels >2000 ng/mL or with ≥20 units of RBC transfusions regardless of SF level in their lifetime, were enrolled. Iron overload was assessed using MRI.

RESULTS

Among 175 patients included, the majority had sickle cell disease (SCD; 52%), followed by aplastic anemia (AA; 17.7%), myelodysplastic syndrome (MDS; 8.6%), Diamond-Blackfan anemia (DBA; 4%), pure red cell aplasia (1.1%), and others (16.6%). Liver iron overload was observed in 76.4% of patients, while cardiac iron overload was seen in 19.2% when assessed by MRI. The prevalence of iron overload was 80.2% in patients with SCD, 73.3% in MDS, 77.4% in AA, 100% in pure red cell aplasia, 71.4% in DBA, and 68.9% in other transfusion-related disorders. A moderate correlation between liver iron concentration (LIC) and SF was observed in patients with SCD and MDS (r = 0.47 and r = 0.61, respectively). All adverse events reported were consistent with the published data for deferasirox or underlying disease.

CONCLUSION

A high prevalence of iron overload in this patient population in Latin American countries indicates that a better diagnosis and management of iron overload is required in these countries.

Clinical characteristics and management of iron overload in 631 patients with chronic transfusion dependency: results from a multicentre, observational study

BACKGROUND

Long-term red blood cell transfusion therapy results in iron overload. Consensus documents have been developed for several transfusion-dependent groups of patients to provide clinicians with guidance on the monitoring and treatment of this transfusion complication. The objective of this study was to describe the clinical characteristics and current standard of care for patients with transfusion dependency in Spain.

MATERIAL AND METHODS

This observational, multicentre study was conducted from November 2008 to December 2009 in 41 Spanish hospitals and day-care centres. Patients who received their first transfusion after January 2007, and who had received at least 10 units of packed red blood cells at the time of inclusion were eligible for the study.

RESULTS

We collected data from 631 patients with a mean age of 65±17 years. Haematological disease (84% of patients) was the most frequent underlying disorder. Patients had received a mean of 30±26 red blood cell units from diagnosis until inclusion in the study, and a mean of 18±18 red blood cell units in the previous year. Ferritin levels were available before and after starting the study for 116 (18%) and 412 (65%) patients, respectively. Mean ferritin level at study inclusion was 1,570 ng/mL, and 58% of patients had a ferritin level of at least 1,000 ng/mL. In spite of this, only 89 (14%) patients were receiving chelation therapy.

DISCUSSION

The management of patients with transfusion dependency could be improved by using ferritin levels to diagnose iron overload and guide the timely start of chelation therapy.

Clinical consequences of iron overload from chronic red blood cell transfusions, its diagnosis, and its management by chelation therapy

Iron overload from chronic transfusion therapy can be extremely toxic. Excess transfusional iron is deposited in the liver, heart, and other organs as free iron, which can cause organ dysfunction and damage over time. Increased awareness of the risk of iron overload in patients requiring chronic transfusion therapy is needed, and such patients should be screened for hyperferritinemia. Those with serial serum ferritin levels exceeding 1000 ng/mL and a total infused red blood cell volume of 120 mL/kg of body weight or more should be treated with chelation therapy and then monitored to ensure that treatment adequately reduces iron levels.