Diagnosis

Assess HScore HLH criteria:

Core tests to send urgently:

• Ferritin (trend is important)
• Fasting triglycerides
• Fibrinogen
• LDH
• D-dimer / coagulation profile
• LFTs
• CRP (often lower than expected vs ferritin)
• U&E

Specific HLH tests:

• Soluble IL-2 receptor (sCD25)
• NK cell activity (if available)

Infection screen (critical differential):

• Blood cultures
• Viral PCRs:
  • EBV
  • CMV
  • HSV
• Hepatitis screen