Adults with Transfusion-Dependent Thalassemia Have Variable Clinical Profiles Depending on Where They Receive Care: Thalassemia Treatment Center Vs Community

Introduction: Advances in the treatment of transfusion-dependent thalassemia (TDT) have decreased complications and improved survival. Established TDT guidelines have improved outcomes through regular red cell transfusions to maintain a pre-transfusion hemoglobin > 9-9.5 g/dL and chelation to maintain a serum ferritin < 1500 ng/mL, liver iron content < 5 mg/g dry weight and a cardiac T2*> 20 ms. Increased lifespan of individuals with TDT now necessitates adult hematology providers with capacity to manage uncomplicated thalassemia. While it is recommended that thalassemia care be provided through a multidisciplinary thalassemia treatment center (TTC), there are a limited number of TTCs in the United States. As a result many adults with TDT receive care in the community from hematologists with variable knowledge and experience with thalassemia. In this study, we thus sought to evaluate the prior care of patients referred to an adult TTC in order to determine if there was a significant difference in the care provided by a pediatric TTC compared to community hematologists.

Methods: We evaluated adult patients (> 18 years old) with a diagnosis of TDT referred to the Penn Comprehensive Adult Thalassemia Program. Patients were either referred from the Children's Hospital of Philadelphia TTC via a dedicated transition program, or from community hematologists (Comm). Data collection was performed via manual chart review. Data collected included the mean of three consecutive pre-transfusion hemoglobin levels prior to the initial visit, serum ferritin, and most recent liver and cardiac iron quantitation by MRI.

Results: Of the 94 patients with thalassemia referred to the adult program between 2013 and 2023, 54 had a diagnosis of TDT. Twenty-seven patients were referred each from the TTC and the community. At the initial adult thalassemia center visit, the median age was 38.5 years (TTC) and 28 years (Comm). More patients in the TTC group maintained a pre-transfusion Hgb > 9 g/dL (78% vs 52%). Serum ferritin trended lower in the TTC group (1725 vs 2629 ng/ml, p-value = 0.056). While 67% of the TTC group had a serum ferritin < 1500 ug/mL compared to 41% in the Comm group, there was no significant difference in the liver iron content between both groups (TTC 10.2 vs Comm 12.2 mg/g dry weight). However, 60% of the TTC group compared to 48% in the Comm group had a LIC < 5. Those followed at the TTC possibly have more cardiac iron with 4 vs 1 patient in the TTC vs Comm group having a T2* < 20 ms, likely reflective of more complicated patients being referred to the TTC.

Conclusion : Patients managed by a TTC were more likely to be adequately transfused with serum ferritins < 1500 ng/mL. Maintaining a pre-transfusion hemoglobin > 9-9.5 g/dL and a serum ferritin < 1500 ng/mL are known to reduce long-term complications of chronic anemia, ineffective erythropoiesis and iron overload in thalassemia. Thus in order to improve long-term outcomes in patients with TDT, we propose that all adult hematology providers, regardless of care setting should aim to gain knowledge on the management of individuals with thalassemia and establish collaborative care relationships with experts in thalassemia care.