BIOMED hs Ferritin
– for the determination of ferritin even in low concentrations
The BIOMED high sensitive (hs) ferritin reagent is used for the quantitative, immunoturbidimetric in vitro determination of ferritin in very low concentration ranges in human serum and plasma using clinical chemistry analyzers (e.g. Siemens Advia Systems, Beckman AU Systems, Roche Cobas Systems).
Performance Characteristics
- Lower detection limit: 2 ng/mL
- No High-Dose-Hook-Effekt up to 50.000 ng/mL
- Measuring range: linear from 5 – 2000 ng/mL
- The linear measuring range of the high sensitive ferritin reagent has been extended from 10 ng/mL to 5 ng/mL in the lower measuring range compared to the classical ferritin reagent.
Precision from Day to Day
Comparison of two sets of control material (Duotrol® Ferritin, 2 levels; Duotrol® CRM Liquid Trilevel, 3 levels) in 2 replicates each on 9 days on the device Beckman AU480.
Precision in the Series
Measurement in 11 replicates in a series of 7 dilutions of the quality control Duotrol® CRM Liquid Trilevel, Level 3, on the AU480.
Linearity
Measurement of 7 dilutions of the quality control Duotrol® CRM Liquid Trilevel, Level 3, in 11 repetitions on the device Beckman AU480.
Comparison of Calibrators
Comparison of two calibrator sets with an extended concentration range and the Duocal® Ferritin calibrator set previously used in routine procedures with 60 individual patient samples on the AU480.
Duocal® Ferritin: 100, 200, 500, 1000 ng/mL
Calibrator Set A: 100, 200, 500, 1000, 2000 ng/mL
Calibrator Set B: 25, 100, 200, 500, 1000 ng/mL
With a correlation coefficient of >0.99 between the three measurement series, there is excellent agreement between the three calibrator sets for the BIOMED hs ferritin.
Device Comparison
A comparative measurement of 386 individual patient samples with BIOMED hs ferritin on an AU5400 and another ferritin reagent on an Abbott Alinity device showed a correlation coefficient of >0.98 between the two measurement series. The analysis was performed on four consecutive days in parallel in both measuring systems.
Background
Ferritin is a protein that represents the most important intracellular storage possibility of iron in the body, which in its free form would have a cytotoxic effect. Each ferritin molecule can store about 4000 iron molecules (Fe3+). The ferritin concentration measured in the patient’s serum is directly related to the total amount of iron present in the body. Ferritin is used as a marker for iron excess disorders and iron deficiency diseases. Excess iron occurs, for example, in porphyria and hemochromatosis. In these diseases the ferritin level in the blood can be exceptional high in combination with low transferrin levels.
Ferritin is an acute phase protein that can also be present in very high concentrations in inflammations caused, for example, by acute, chronic diseases or infections. In this case, the measured ferritin concentration may be high although there is an iron deficiency. The determination of the inflammation marker C-reactive protein (CRP) can help to exclude a misinterpretation of the measurement results due to high serum levels of ferritin.
A low ferritin level is an indication of an insufficient amount of iron in the body, which may lead to anemia. Iron deficiency can occur in all phases of life, but pregnant women and small children are particularly affected. Recent studies have shown that there also may be a link between iron deficiency and obesity. In 2002, the WHO considered iron deficiency anaemia to be one of the most important factors in the global burden of disease. Iron deficiency is found in about 30% of patients with heart failure and is usually classified as chronic anemia. The serum ferritin test is the most sensitive laboratory test for the determination of iron deficiency anaemia.
The lower standard values for ferritin are usually too low in the specialist literature, a ferritin concentration of <30 ng/mL in women and men is regarded as an indication of insufficient iron storage. In contrast, however, the first symptoms of iron deficiency often occur at ferritin levels below 50 ng/mL. Many clinical doctors therefore suggest increasing the lower ferritin standard to at least 50 ng/mL.
Keywords
Iron storage disease, iron deficit, iron storage protein, storage iron, haemoglobin, haemoglobin synthesis, iron deficiency anaemia, particle enhanced immunoturbidimetric test, latex reagent, turbidimetry
Literature
・L. Thomas: Labor und Diagnose, 2016, e-Version
・Guder, W.; Zawta, B.: Die Qualität diagnostischer Proben, 2000, 2.Aufl.
・Roberto Herklotz, Andreas Huber: Labordiagnose von Eisenstoffwechselstörungen, Swiss Medical Forum, 2010: S. 500-507.
・Beat Schaub et al.: Eisenmangel ohne Anämie, Österreichische Ärztezeitung (7), 10. April 2008, WHO Bulletins.