Hyperferritinemia: causes and significance in a general hospital

To elucidate conditions which cause elevation of the serum ferritin, extent of the elevation in each condition, and clinical relevance of hyperferritinemia in general practice.

We retrospectively studied medical records of all patients who had at least one serum ferritin measurement above 500 μg L^-1. Patients who had a marked elevation of the serum ferritin over 10,000 μg L^-1 were studied separately.

We studied 1394 patients to identify the etiologies of hyperferritinemia. Median serum ferritin level was 1024 μg L^-1 and 49.2% had ferritin levels of 501-1000 μg L^-1. The most frequent cause of hyperferritinemia was non-human immunodeficiency virus infection followed by solid tumor, liver dysfunction, renal failure, and hematological malignancy. The distributions of the causes were different among groups stratified by the ferritin level. Forty-one percent had multiple causes and there was a tendency that the more underlying causes a patient had, the higher the ferritin level. Each condition led to a wide range of the ferritin level, and some patients could present with marked hyperferritinemia. Seventy percent of 111 patients with marked hyperferritinemia had multiple etiologies and a variety of diseases could lead to marked hyperferritinemia by themselves.

Patients with hyperferritinemia frequently had multiple conditions. The level of the serum ferritin was determined by the underlying conditions to a certain extent; however, the variation was significant. While patients with marked hyperferritinemia mostly had multiple underlying causes, various diseases could cause hyperferritinemia by themselves.

Hyperferritinemia is associated with both etiology and the number of underlying causes.