Hemoglobin disorders in Europe: a systematic effort of identifying and addressing unmet needs and challenges by the Thalassemia International Federation

Abstract

Hemoglobin disorders (thalassemia and sickle cell disease) are a group of hereditary anemias that today occur across the world. The recent population movement has led to a steady increase of carriers and patients in all countries of the European Union. Requiring complex monitoring and treatment and, as a consequence, well-organized and nationally coordinated, supported and funded services, these lifelong conditions are now visible to healthcare services in the EU. The purpose of this study is to provide an overview of the current situation pertaining to these disorders, as perceived by the patient/parent community that the Thalassemia International Federation (TIF) represents. The aim is to establish a comprehensive understanding of the situation and unmet needs faced by migrants with thalassemia. The implementation of activities by TIF in 2018-2020 to identify and address these challenges, paves the way to increased awareness, education and policy changes building on international expertise and knowledge that will enable the provision of state-of-art clinical management services thus guaranteeing an improved quality of life. A bird’s eye view of the prevalence of these disorders is presented contributing to the further understanding of challenges met by both patients and healthcare professionals in the receipt and provision of quality healthcare respectively. Introduction Hemoglobin disorders are a group of hereditary anemias caused by genetic mutations affecting the production of the globin chains of the hemoglobin molecule. Their prevalence seems to be related to past or present prevalence of Plasmodium falciparum malaria across the globe, since it appears that healthy carriers have a selective advantage over non-carriers as far as survival to malarial infection is concerned. There is a geographical coincidence of haemoglobinopathy prevalence, with those parts of Europe where malaria was rampant in the past.1 Cyprus is a primary example of this phenomenon, since until its eradication in 1948, malaria was a major public health problem; the beta thalassemia carrier rate was recorded to be 15-18%.2 Lowland regions of Greece, Italy and Turkey were similarly affected. Geographical distribution in Europe High prevalence globally, for both thalassemia and sickle cell disease (SCD), appears to range from the Mediterranean basin across Africa and the Middle East to the Far East reaching the Pacific coast. In the European setting, the countries in which the indigenous population is most affected are the South of France, Italy, Greece, Albania, Turkey and the Mediterranean islands. Some countries to the north of these, such as the Balkans are less affected as is the Iberian Peninsula. Southern Russia and the Caucasus have a variable prevalence, with the exception of Azerbaijan which has a high prevalence. North of these areas are most European countries where beta and alpha thalassemia are extremely uncommon (with around 0.1-0.2% of the population being heterozygotes), while sickle cell genes and other variants are almost unknown in the indigenous populations (Figure 1). Historical population movements in the early and mid-20th century from high prevalence countries have introduced these disorders to the countries of Western Europe (e.g. UK and France) and the Americas (e.g. USA, Canada and Brazil). Furthermore, more recent population movements to Europe, of different causality, voluntary or forced, have changed the European landscape in the area of hemoglobin disorders, and have led to a steady increase of carriers and patients in all countries of the European Union, including formerly low prevalence countries such as Scandinavian countries (viz. Denmark, Sweden) and Central European countries (v. Slovakia, Czech Republic).3,4 A migration flow from the east has followed a transit route through Turkey, Greece and the Balkans aiming to reach the countries of Western and Northern Europe (mainly France, Germany and Sweden). From Africa, the origin of most sickle cell carriers, increasing numbers are entering the European continent mainly across the Mediterranean to Italy and Spain. Some among of the persons originating from high prevalence countries of the Middle East, South East Asia and sub-Saharan Africa are likely to be healthy carriers of these disorders or indeed patients. Likewise, persons from Afghanistan, Iraq, Syria, Thailand and Turkey, entering Europe from the Eastern borders of Greece and the Balkans might be carriers of thalassemia or HbE genes. In Germany, only about 1000-1500 sickle cell patients were recorded in 2014, while in 2016 a neonatal screening study revealed that 1 in 2385 newborns are SCD carriers, probably of Sub-Saharan ancestry.5,6 The documented number of people settling in Europe until 2015 from high prevalence areas and the subsequent estimated number of carriers based on prevalence rates in their countries of origin is demonstrated in Table 1.8-14 In the absence of an internationally accepted definition of migrant, in this publication the term will be used to define any individual who lives outside their country Thalassemia Reports 2021; volume 11:9803 Correspondence: Androulla Eleftheriou, Executive Director, Thalassemia International Federation; 31, Ifigenias Street, 2007 Strovolos, Nicosia, Cyprus. Tel.: +35.722319129. E-mail: [email protected]