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ascertained the potential suitability of the donor on the basis of the general criteria outlined in Section 4, a detailed medical history should be taken, using a structured donor questionnaire and interview. This is aimed at identifying and deferring, either temporarily or permanently, any donor with a medical condition that may predispose the donor to immediate or long-term harm, affect the safety or quality of the product derived from the blood or compromise patient safety. 5.1 HAEMATOLOGICAL DISORDERS Assessment of the suitability of prospective donors with haematological disorders is based on the need to avoid any risks of anaemia, bruising and haematoma or thrombosis as a result of the venepuncture. Chronic anaemia may be associated with ill health and such individuals are not suitable to donate blood. Also refer to Sections 5.9 on malignant diseases and 6.3 on blood transfusion and transplantation. 5.1.1 Anaemia, including haematinic (iron, B12 and folate) deficiency The history of anaemia should be assessed in relation to its cause, current status and any treatment that has been received. Individuals who suffer from haematinic deficiency anaemia of whatever etiology should not be accepted as donors until the cause of the anaemia has been identified and the anaemia has been successfully treated. Recommendations Accept n Individuals who: — Have a past history of iron deficiency anaemia, with a known cause that is not a contraindication to donation, and who have completed treatment and are fully recovered — Have a past history of B12 or folate deficiency, are fully recovered and are taking maintenance treatment with B12 or folic acid Defer n Individuals who: — Do not meet the minimum haemoglobin level for blood donation — Are under investigation or on treatment for anaemia Defer permanently n Individuals who have chronic anaemia of unknown cause or associated with systemic disease: e.g. renal failure, rheumatoid disease 50 5.1.2 Haemoglobinopathies The prevalence of inherited haematological conditions in different countries should be taken into account in defining donor acceptance and deferral criteria. Individuals with thalassaemia major and sickle cell disease are not suitable as blood donors (70). The sickle cell trait impairs the effective filtration of blood for leucodepletion (115,116). Most BTS do not accept donors with sickle cell trait for apheresis donations or for whole blood donations if the blood is to be leucofiltered. Blood from donors with sickle cell trait is not suitable for intrauterine transfusion or neonatal exchange transfusion (64); it is also unsuitable for patients with sickle cell disease (67) as it may exacerbate sickling of the red cells. Recommendations Accept n Individuals with: — Thalassaemia traits, provided they are well and meet the minimum haemoglobin level for blood donation — Sickle cell trait: accept for whole blood donation provided they meet the minimum haemoglobin level for blood donation; blood donated by sickle cell trait individuals is, however, not suitable for leucodepletion, intrauterine transfusion, neonatal exchange transfusion or for patients with sickle cell disease Defer permanently n Individuals with: — Thalassaemia major or sickle cell disease — Sickle cell trait for blood donation by apheresis procedure or for whole blood donation if the blood is to be leucofiltered 5.1.3 Enzymopathies and inherited red cell membrane defects Glucose-6–phosphate dehydrogenase (G6PD) deficiency is the most common red cell enzyme defect, with hundreds of molecular variants. Most variants have only slightly subnormal red cell survival; however, others (e.g. the Mediterranean variant) render the cells highly susceptible to oxidative stress. Blood from individuals with G6PD deficiency (with a history of haemolysis) is therefore unsuitable for transfusion as haemolysis may be precipitated if the recipient develops an infectious illness or ingests an oxidative drug or fava beans (117). People with the next most common inherited enzyme defect, pyruvate kinase deficiency, will usually be too anaemic to donate, even if asymptomatic. Red cell membrane disorders are inherited diseases due to mutations in various membrane or skeletal proteins, resulting in decreased red cell deformability, reduced life span and premature removal of the erythrocytes from the circulation. Red cell membrane disorders include hereditary spherocytosis, hereditary elliptocytosis, hereditary ovalocytosis and hereditary stomatocytosis (118). 51 Recommendations n Policies for the assessment of prospective donors should be developed by BTS in regions where there is a high incidence of enzymopathies and inherited red cell membrane defects

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