A 55-year-old woman with rheumatoid arthritis is referred to the haematology outpatient department by her General Practitioner. She consulted him because of symptoms of profound fatigue and tinnitus and a routine full blood count had revealed her to be anaemic. Haemoglobin was 10.3 g/dl, mean cell volume (MCV) 82 fl, white cell count 5.6 (neutrophils 3.5, lymphocytes 2.1) × 109/l and platelets 287 × 109/l. Her doctor could not establish a clear-cut cause for this lady’s anaemia and has sought further advice.
What is the clinical approach to managing this patient?
What investigations should be performed?
As in any other clinical scenario, the investigation of this patient hinges on an accurate history and examination. In terms of causes of anaemia, the most common by far is iron deficiency and the likelihood of this as an explanation should be fairly clear by paying close attention to diet history, enquiring for gastrointestinal symptoms and obtaining a gynaecological history in females. A lot of information can be gleaned from the full blood count result, the key parameter being red blood cell (RBC) size. In terms of aetiology, the classification of anaemias (Figure 7.1) is best approached based around the MCV. Clearly in uncomplicated iron deficiency, patients will have a microcytic hypochromic blood film, and it is debatable whether such patients need referral to a specialist haematology clinic. The common causes of iron deficiency are related to occult gastrointestinal blood loss or menorrhagia and the appropriate management of such cases lies with the appropriate specialty.
The approach to the anaemic patient. DCT, direct Coombs' test; GiFAbs, growth inhibitory factor antibodies; Hb, haemoglobin; thal, thalassaemia; WCC, white cell count.
However, this case presents one of the commonest diagnostic dilemmas – the patient with a normocytic anaemia in whom haematinic levels are normal and there is no morphological evidence of bone marrow failure or haemolysis. It is a common problem, the presence of which increases with age. Often patients are asymptomatic, the condition being discovered by ‘routine’ laboratory tests. Although all causes of microcytic and macrocytic anaemias can on occasion present with a normocytic anaemia, often in this situation one is dealing with a decreased production of normal-sized RBCs, as occurs in the anaemia of chronic disease (ACD) but also in aplastic anaemia. A similar appearance can occur in an uncompensated increase in plasma volume, for example in pregnancy or fluid overload. Anaemia of chronic disease is thought to be the most common form of normocytic anaemia and probably the second most common form of anaemia worldwide after iron-deficiency anaemia. It is often a disease of exclusion and the pathogenesis is usually multifactorial and thought to be related to hypoactivity of the bone marrow with relative inadequate production of erythropoietin (EPO) ...