Efficacy of calcineurin inhibitors in interstitial lung disease of patients with antisynthetase syndrome: a systematic literature review and single-arm prevalence meta-analysis.

Ferritin is one of the most requested blood tests in both primary and inpatient care, and high values occur frequently. One of the greatest challenges in the investigation of hyperferritinemia is to determine if there is a presence of iron overload. Patient history (chronic liver disease, excessive alcohol consumption, hereditary factors), clinical features (metabolic syndrome, acute or chronic inflammation, infection, malignancy) and biochemical tests (ferritin, transferrin saturation, hemoglobin, liver enzymes, CRP/SR, phosphatidyl ethanol, lipid profile, glucose) facilitate the determination of the cause of hyperferritinemia. High transferrin saturation indicates iron overload, which is usually linked to hereditary hemochromatosis. In the case of homozygosity of the HFE mutation p.C282Y in the presence of hyperferritinemia, venesection can be started without further investigations, while in the absence of HFE mutations a possible iron excess must be validated with magnetic resonance imaging (MRI) for iron determination before venesection is started. Dysmetabolic iron overload syndrome (DIOS) or alcohol-related hemosiderosis can be treated with venesection in selected cases if there is a significant deposition of iron in the liver on MRI. An individual with ferritin below 1000 µg/L, a normal transferrin saturation, and normal liver tests does not need further investigations and can be followed in primary care. We propose an algorithm for the investigation of hyperferritinemia that facilitates the investigation both in primary and inpatient care.