Correct!
5. All of the above
The diagnosis of HLH requires at least 5 of 8 criteria “HLA-2004” criteria are met (1). However, completing the diagnostic work-up is time-consuming. A bone marrow biopsy is often delayed unless the intensivist performs it themselves. sIL2-R and NK cell activity tests are send-outs that often take 1-2 weeks to result. Patients in shock and multi-system organ failure from secondary HLH are at high mortality risk, and empirical immunotherapy should be started if clinical suspicion is high, as in this case, while the diagnosis is being confirmed.
Intravenous methylprednisolone, 60mg every six hours was started. A bone biopsy was performed by the intensivist. A marrow smear from the patient is shown in Figure 2. The bone marrow was infiltrated by large numbers of histiocytes, many of which were ingesting hematopoetic cells normally residing in the bone marrow.
Figure 2. Phagocytosis of a neutrophil, platelets and red blood cells by a single histiocyte (a tissue-residing macrophage).
Soluble interleukin-2 receptor was 6265 u/mL (normal 241-846) and natural killer cell activity was undetectable. An abdominal ultrasound showed mild hepatosplenomegaly.
What is the best diagnosis? (Click on the correct answer to be directed to the fifth of six pages)