Prevalence of Extramedullary Hematopoiesis, Vertebral, Hepatic and Splenic Hemangioma and Renal Cyst Among Thalassaemic Patients: A Retrospective Study from the Myocardial Iron in Thalassemia (MIOT) Network

BACKGROUND : The prevalence and the clinical relevance of several extracardiac findings (EF) at Magnetic Resonance Imaging (MRI) have been recently estimated in cohorts of non thalassaemic patients. AIM: In this study we sought to determine the prevalence of EF potentially related to anaemia and ipoxia in age- and sex- matched populations with thalassaemia major (TM) and Thalassaemia Intermedia (TI). METHODS: We retrospectively considered 159 TM patients regularly transfused (73 F; 34±9.20 years) and 159 TI patients (73 F; 34±9.18 years ) consecutively enrolled in the Myocardial Iron in Thalassemia (MIOT) Network to quantify cardiac and liver iron by T2* technique. Patients with TI were further subdivided in non transfusion dependent (NTD-TI) and transfusion dependent (TD-TI). All MRI images were used to assess the presence or absence of Extramedullary Hematopoiesis (EMH), kidney, splenic and liver cysts, and vertebral hemangiomas. RESULTS: Overall, EF were detected in 33% and 26% of patients with TI and TM, respectively. Table 1 shows the comparison of MRI data between TM and TI patients. Both groups of patients had elevated but comparable prevalence of k idney, splenic and liver cysts and vertebral haemangiomas . TI patients were found to have significant higher EMH as compared to TM. The prevalence of total EF increased with advancing age and renal cysts were found in the 28.6% of the cohort aged 45-55 years. Patients with renal cysts had comparable serum creatinin level with respect to those without. Within the population of TI-TD it was observed the highest prevalence of patients with renal cysts, splenic cyst and vertebral haemangioma (26%, 3% and 3%, respectively). Thalassemic patients had a was significant higher prevalence of renal cysts than the general population (19.2 vs 7.8%; P CONCLUSIONS: EF are well-recognized features in patients undergoing MRI, being hepatic cysts or hemangiomas and renal cyst the most frequently observed. Our data on hemangiomas and renal cysts, particularly among patients with TI-TD, indicate a significant higher prevalence of EF compared to the general population. These data seem to suggest the role of the inappropriate activation of the Hypoxia-Inducible Factor (HIF) system linked to the chronic hypoxia as observed in the Chuvash polycythemia or in the the von Hippel-Lindau (VHL) syndrome. Furthermore, HIF in general population has been directly involved in the development and/or progression of clear cell renal cancer also described among thalassemic patients. Disclosures Pepe: Chiesi: Speakers Bureau; ApoPharma Inc: Speakers Bureau; Novartis: Speakers Bureau.