Laboratory diagnosis of anaemia in dialysis patients: use of common laboratory tests

Almost all patients with end-stage renal disease suffer from renal anaemia of multifactorial pathogenesis. The use of recombinant human erythropoietin to raise the haematocrit has been a major advance in the care of patients with end-stage renal disease. The majority of these patients develop absolute or functional iron deficiency. However, the diagnosis of iron deficiency is hindered by the inaccuracy of commonly used tests. Serum ferritin and transferrin saturations are frequently used, but limitations with both parameters in end-stage renal disease patients have resulted in the development of new tests to assess iron sufficiency. The percentage of hypochromic red blood cells and particularly reticulocyte haemoglobin content are new measures of iron status in end-stage renal disease patients. An enhanced knowledge of the interpretation of available laboratory parameters will ensure that the patients receive the full benefit from their treatment with recombinant human erythropoietin and iron.