Haematology and Oncologycommon
A 46-year-old man develops jaundice, dark urine and exertional dyspnoea over several weeks. He has splenomegaly, a haemoglobin concentration of 78 g/L (130–170), an increased reticulocyte count and raised lactate dehydrogenase, with no recent transfusion or new medication. The direct antiglobulin test is positive for immunoglobulin G but negative for complement. Which one of the following is the most likely diagnosis?