PGY3 Chris Foss presenting a very interesting case of a 34 year old male with no PMH who presented with fevers, vague GI symptoms and acute encephalopathy who was found to have fevers, pancytopenia, elevated liver enzymes and elevated ferritin. CT C/A/P revealed hepatosplenomegaly and diffuse lymphadenopathy concerning for lymphoma. Bone marrow biopsy did not show malignancy or evidence of hemophagocytosis. Rheumatologic and infectious work-up were negative, other than positive EBV DNA PCR. Based on patient’s clinical and laboratory findings there was high suspicion for Hemophagocytic Lymphohistiocytosis (HLH) and empiric treatment was initiated. The patient is currently pending a quantitative EBV DNA level and lymph node biopsy to determine his trigger for HLH.
HLH is a syndrome of excess immune activation and can be triggered by various events including infection, neoplasms and autoimmune diseases. It is a life-threatening condition and requires prompt recognition and initiation of therapy.
Diagnosis of HLH requires identification of an HLH associated gene mutation or five of eight of the following:
3. Peripheral blood cytopenias (at least two of: Hgb<9, Plt<100, ANC<1000)
4. Hypertriglyceridemia (Fasting>265) and/or hypofibrinogenemia (<150)
5. Evidence of hemophagocytosis (bone marrow, LN, liver)
6. Low/abset NK cell activity
7. Ferritin >500
8. Elevated soluble CD25
-A negative bone marrow biopsy does not rule out HLH. Studies have shown that marrow histologic findings do not reliably predict the probability of HLH.
-Important triggers for HLH include infections (viral infections more common such as EBV, CMV, HSV, HIV), malignancy (lymphomas/leukemias), and rheumatologic disorders.
Thank you Chris for doing a great job with such a complex patient and teaching us all about HLH!