Should hepatitis E serology be repeated in a patient with confirmed hepatitis E, psoriasis on immunosuppressants, now presenting with vomiting, abdominal pain, and liver tenderness?

Yes, you absolutely need to repeat HEV testing with HEV RNA (NAT) immediately in this immunosuppressed patient presenting with new hepatic symptoms.

In an immunosuppressed patient with confirmed hepatitis E who develops new symptoms of vomiting, abdominal pain, and liver tenderness, you must perform HEV RNA testing (nucleic acid amplification testing/NAT) to assess for chronic infection or reactivation, as serology alone is unreliable in this population 1.

Why Repeat Testing is Critical

Serology is Unreliable in Immunosuppressed Patients

• Anti-HEV antibodies (both IgM and IgG) can remain negative despite persistent viral replication in immunosuppressed patients 1
• Your patient on immunosuppressants for psoriasis falls into the high-risk category where antibody responses may be blunted or absent
• This makes NAT testing mandatory—it's the only reliable diagnostic method in this setting 1

Risk of Chronic Infection

Immunosuppressed patients fail to clear HEV in up to 50-67% of cases, developing chronic hepatitis 1. Key points:

• Chronic HEV is defined as persistent HEV RNA for >3 months, though most patients who remain viremic beyond 3 months will not spontaneously clear 1
• Patients with rheumatic disorders on heavy immunosuppression (like your psoriasis patient) behave similarly to transplant recipients in terms of chronicity risk 1
• Chronic HEV can rapidly progress to cirrhosis and even death in immunosuppressed patients 1

New Symptoms Demand Investigation

The presentation of vomiting, abdominal pain, and liver tenderness could represent:

• Progression to chronic hepatitis (most likely if >3 months from initial diagnosis)
• Acute flare of ongoing infection
• Drug-induced liver injury (DILI) from immunosuppressants—but HEV must be ruled out first 1

What Testing to Order Now

Order both:

1. HEV RNA by NAT (serum/plasma) - This is the gold standard 1
2. HEV RNA in stool if available - Increases diagnostic sensitivity 1
3. Liver function tests (ALT, AST, GGT, bilirubin) to assess severity
4. Repeat anti-HEV IgM and IgG - Though less reliable, may provide supportive data 1

Critical Pitfall to Avoid

Do not rely on negative serology to exclude active HEV infection in immunosuppressed patients. The guidelines explicitly state that NAT is mandatory because antibodies are often undetectable despite ongoing viral replication 1.

Timeline Considerations

If this patient was diagnosed with HEV:

• <3 months ago: Test now to determine if spontaneous clearance is occurring or if chronic infection is developing
• >3 months ago: Assume chronic infection if HEV RNA is still positive and consider treatment 1

Next Steps Based on Results

If HEV RNA is positive:

• Consider reducing immunosuppression if clinically feasible for the psoriasis
• If viremia persists >3 months from initial infection, initiate ribavirin therapy 1
• Monitor HEV RNA levels to assess treatment response

If HEV RNA is negative:

• Consider other causes of hepatitis (DILI from immunosuppressants, autoimmune hepatitis)
• But maintain high suspicion—repeat testing if symptoms persist 1

The EASL guidelines are unequivocal: all immunosuppressed patients with unexplained abnormal liver tests require HEV testing (A1 recommendation) 1. Your patient meets this criterion with new hepatic symptoms, making repeat NAT testing not just recommended but essential for proper management and to prevent progression to cirrhosis.