ABSTRACT
Background: Elevated
serum ferritin is more commonly due to reactive causes such as infection, hepatic disorders, rheumatologic conditions,
and malignancy than true iron overload. Extreme hyperferritinemia (>10,000
ng/mL), on the other hand, should prompt consideration of rare conditions such
as adult-onset Still’s disease (AOSD) or hemophagocytic lymphohistiocytosis. This paper aims to present the case of the highest reported extreme
hyperferritinemia (actual level 256,000 ng/mL) in a patient eventually
diagnosed with adult onset Still’s Disease (AOSD). Case
Presentation: A 55-year-old male,
Filipino, was admitted due to acute onset fever and shortness of breath. He was
initially assessed to have community-acquired pneumonia and a suspect for
coronavirus disease 2019 (COVID-19), hence inflammatory markers were requested.
Ferritin was notably elevated at 44,255 ng/mL. He eventually tested negative
for COVID-19 RT-PCR. He was investigated for other causes of markedly elevated
ferritin levels. His complete blood count (CBC) only showed leukocytosis with
no peripheral blasts, iron level and liver function tests were normal, HIV
immunoassay was negative, ANA was 1:80 speckled with normal complement level,
rheumatoid factor negative, and positron emission tomography (PET) scan revealed
presence of lymphadenopathies and did not show solid tumors. He was treated for
urinary tract infection and pneumonia but still had intermittent fever and
increasing ferritin trend, with the highest documented level at 256,000 ng/mL.
Fulfilling the Yamaguchi criteria, he was managed as a case of severe AOSD and
received tocilizumab. He had lysis of fever and decreasing trend of ferritin
levels thereafter, with ferritin level of 34,184 ng/mL three weeks after
tocilizumab infusion. He was discharged and improved with prednisone and
methotrexate as home medications. Conclusion: To our
knowledge, the highest level of extreme hyperferritinemia recorded in
literature as of 2016 is 143,931 ng/mL, which was associated with hematologic
malignancy. This case documents the highest noted ferritin level of 256,000
ng/mL associated with AOSD. AOSD remains a diagnosis of
exclusion due to its nonspecific symptoms and absence of definitive tests. The
treatment comprises NSAIDs, steroids, and immunosuppressives; however biological
treatments such as tocilizumab can be considered in severe cases.