RESUMEN
BACKGROUND: The clinical significance of extreme hyperferritinaemia has come under scrutiny with the increasing recognition of haemophagocytic lymphohistiocytosis (HLH) in adults. Most studies of hyperferritinaemia have focused on serum ferritin greater than 1000 µg/L, often in ambulatory patients. The conditions associated with more extreme hyperferritinaemia are poorly understood. AIMS: To examine conditions associated with extreme hyperferritinaemia greater than 3000 µg/L in acutely ill adults at a quaternary care hospital. METHODS: Patients with serum ferritin greater than 3000 µg/L at Vancouver General Hospital between 1 August 2011 and 1 August 2012 were identified. Those over 18 years of age and with clinical data available were included in the study. RESULTS: Eighty-three subjects were identified. Twenty-one cases (25%) were due to transfusional iron overload, 16 (19%) due to liver disease and 15 (18%) due to mixed factors. Haemophagocytic lymphohistiocytosis (HLH) was diagnosed in six of 83 patients (7%) with ferritin greater than 3000 µg/L, but six of eight patients (75%) with ferritin greater than 20 000 µg/L. CONCLUSIONS: Extreme hyperferritinaemia greater than 3000 µg/L is uncommon in adult patients. The highest serum ferritin values are seen in HLH, but the differential diagnosis for serum ferritin greater than 3000 µg/L remains broad with iron overload and liver disease being the most common causes.