1st order laboratory parameters – obligatory laboratory tests.
- Small blood count
- Differential blood count
- Inflammatory parameter – CRP (C-reactive protein)
- Serum iron, plasma ferritin* , transferrin saturation* * (suspected in men > 45%, pre-menopausal women > 35%).
- Fasting glucose (fasting blood glucose), HbA1c
- Liver parameters – alanine aminotransferase (ALT, GPT), aspartate aminotransferase (AST, GOT), glutamate dehydrogenase (GLDH) and gamma-glutamyl transferase (gamma-GT, GGT), alkaline phosphatase, bilirubin [ALT > AST].
- Renal parameters – urea, creatinine, cystatin C or creatinine clearance, if necessary.
- Coagulation parameters – PTT, Quick
* Ferritin levels > 300 ng/ml → causes of primary or secondary hemochromatosis should be excluded.
* * Ferritin levels > 300 ng/ml + transferrin saturation > 50% → molecular genetic testing of the HFE gene required.
2nd order laboratory parameters – depending on the results of the history, physical examination and obligatory laboratory parameters -.
- Molecular genetic examination – mutation analysis HFE gene* (C282Y, H63D), examination also in siblings* * .
- FSH, testosterone – if hypogonadotropic hypogonadism is suspected.
* Prevalence of C282Y homozygosity is 80.6% in clinically apparent HH disease, compound heterozygosity for C282Y/H63D is 5.3%. Penetrance of C282Y homozygosity varies depending on definitions of laboratory or clinical penetrance: up to 38-50% of all C282Y homozygotes have iron overload and 10-33% develop hemochromatosis-associated disease at some point. In general, studies show higher penetrance in males.
* * Family screening is strongly recommended in siblings of HH patients, by annual monitoring of ferritin and transferrin saturation and genetic testing (DNA analysis) after appropriate counseling (Clinical Practice Guidelines for HFE – Hemochromatosis 2010, EASL – European Association for the Study of the Liver).
