What is the workup for elevated percent iron saturation and elevated ferritin with negative HFE (Human Ferritin Encoding) testing?

Workup for Elevated Iron Saturation and Ferritin with Negative HFE Testing

When HFE testing is negative despite elevated transferrin saturation and ferritin, you must systematically exclude secondary causes of iron overload and hyperferritinemia, then consider non-HFE hemochromatosis genes, and finally pursue hepatic iron quantification to confirm true iron overload. 1, 2, 3

Initial Assessment: Exclude Secondary Causes

Before pursuing genetic causes, rule out the most common culprits that account for over 90% of hyperferritinemia cases 2, 4:

Liver Disease Evaluation

• Chronic alcohol consumption - obtain detailed alcohol history, as this increases iron absorption and causes hepatocellular injury 2, 4
• Non-alcoholic fatty liver disease (NAFLD)/metabolic syndrome - assess BMI, waist circumference, glucose, lipids, and consider hepatic steatosis imaging 2, 4
• Viral hepatitis - test for hepatitis B surface antigen and hepatitis C antibody 4, 3
• Autoimmune hepatitis - check ANA, anti-smooth muscle antibody, and immunoglobulins, as this can rarely present with elevated transferrin saturation mimicking iron overload 5

Inflammatory and Systemic Conditions

• Inflammatory markers - measure CRP and ESR to detect occult inflammation 2, 4
• Malignancy screening - consider age-appropriate cancer screening, as solid tumors and lymphomas commonly elevate ferritin 2, 4
• Rheumatologic conditions - if ferritin is extremely elevated (>4,000 ng/mL), check glycosylated ferritin fraction (<20% suggests adult-onset Still's disease) 4
• Chronic kidney disease - check creatinine and eGFR 4

Hematologic Disorders

• Complete blood count with differential - evaluate for anemia, which may suggest thalassemia, myelodysplastic syndrome, or sideroblastic anemia 2, 3
• Peripheral blood smear - look for abnormal red cell morphology 3
• Hemoglobin electrophoresis - if microcytic anemia or family history suggests thalassemia 3

Hepatic Iron Quantification

If secondary causes are excluded and iron overload remains suspected, quantify hepatic iron concentration to confirm true iron overload 1, 2:

MRI-Based Assessment

• Hepatic MRI with iron quantification is the preferred non-invasive method to measure liver iron concentration 1, 2
• This definitively distinguishes true iron overload from hyperferritinemia without iron accumulation 1, 6

Liver Biopsy Considerations

Consider liver biopsy when 1, 2:

• Ferritin >1,000 μg/L with elevated liver enzymes (ALT/AST) and platelet count <200 (predicts cirrhosis in 80% of cases) 2
• MRI is unavailable or contraindicated 1
• Concurrent liver disease evaluation is needed 3, 6
• Hepatic iron index calculation is required for diagnosis 6

Non-HFE Hemochromatosis Genetic Testing

If hepatic iron overload is confirmed but HFE testing is negative, pursue genetic testing for non-HFE hemochromatosis genes 1, 2, 3, 7:

Gene Panel Selection Based on Clinical Presentation

Juvenile hemochromatosis (age <30 with cardiac/endocrine manifestations):

• HJV (hemojuvelin) gene - test for p.Gly320Val mutation first 7
• HAMP (hepcidin) gene 1, 3, 7

Adult-onset iron overload:

• TFR2 (transferrin receptor 2) gene 1, 3, 7
• SLC40A1 (ferroportin) gene - particularly if autosomal dominant inheritance pattern 1, 3, 7

Risk Stratification and Monitoring

Based on Ferritin Levels

• Ferritin <1,000 μg/L - low risk of cirrhosis, can proceed with phlebotomy if iron overload confirmed 1, 2
• Ferritin 1,000-10,000 μg/L - check platelet count and liver enzymes; if platelets <200 with elevated enzymes, high cirrhosis risk requiring biopsy 2
• Ferritin >10,000 μg/L - rarely represents simple iron overload; urgent specialist referral for life-threatening conditions 2, 4

Critical Pitfalls to Avoid

• Never rely on ferritin alone - always interpret in context of transferrin saturation, as ferritin is an acute phase reactant 1, 2, 6
• Do not assume absence of iron overload - negative HFE testing does not exclude hereditary hemochromatosis, as non-HFE mutations account for significant cases 1, 3, 7
• Recognize compound heterozygotes (C282Y/H63D) rarely cause significant iron overload alone - investigate other contributing factors 2
• Consider functional iron deficiency - in inflammatory states, ferritin rises while transferrin saturation drops, creating elevated ferritin without true iron overload 2, 4

Family Screening

If non-HFE hemochromatosis is confirmed, screen first-degree relatives with 2:

• Transferrin saturation and serum ferritin 2
• Targeted genetic testing for the identified mutation 2