Extreme hyperferritinemia: etiological spectrum and impact on prognosis

Area of Science:

• Hematology
• Clinical Pathology

Background:

• Hyperferritinemia, or elevated serum ferritin, can stem from various conditions including inflammation, infection, iron overload, and hemophagocytic lymphohistiocytosis (HLH).
• The clinical significance and prognostic implications of extreme hyperferritinemia remain unclear.

Purpose of the Study:

• To investigate the diagnostic spectrum and clinical associations of patients presenting with serum ferritin levels exceeding 2000 μg L-1.
• To evaluate the utility of the H score in identifying hemophagocytic lymphohistiocytosis (HLH) in this patient cohort.

Main Methods:

• Retrospective review of 77 patients with serum ferritin >2000 μg L-1 admitted between 2015-2017.
• Assessment of the H score for HLH probability and comparison with diagnoses and laboratory findings.
• Correlation analysis between ferritin levels, hemophagocytosis, and mortality.

Main Results:

• Hematological malignancy (n=20) and severe infection (n=14) were the most common diagnoses. Eleven patients were diagnosed with HLH.
• Ferritin levels >6000 μg L-1 correlated significantly with hemophagocytosis and increased mortality.
• The HLH subgroup exhibited higher rates of fever, cytopenia, hemophagocytosis, and liver dysfunction. The H score was elevated in patients with ferritin >6000 μg L-1, predicting higher HLH probability.

Conclusions:

• Extreme hyperferritinemia is not specific but a ferritin level >6000 μg L-1 is significantly associated with HLH diagnosis.
• The H score serves as a valuable screening tool for ruling out HLH in critically ill patients with hyperferritinemia.