Optimizing hepcidin measurement with a proficiency test framework and standardization improvement

Abstract

ObjectivesHepcidin measurement advances insights in pathophysiology, diagnosis, and treatment of iron disorders, but requires analytically sound and standardized measurement procedures (MPs). Recent development of a two-level secondary reference material (sRM) for hepcidin assays allows worldwide standardization. However, no proficiency testing (PT) schemes to ensure external quality assurance (EQA) exist and the absence of a high calibrator in the sRM set precludes optimal standardization.MethodsWe developed a pilot PT together with the Dutch EQA organization Stichting Kwaliteitsbewaking Medische Laboratoriumdiagnostiek (SKML) that included 16 international hepcidin MPs. The design included 12 human serum samples that allowed us to evaluate accuracy, linearity, precision and standardization potential. We manufactured, value-assigned, and validated a high-level calibrator in a similar manner to the existing low- and middle-level sRM.ResultsThe pilot PT confirmed logistical feasibility of an annual scheme. Most MPs demonstrated linearity (R2>0.99) and precision (duplicate CV>12.2%), although the need for EQA was shown by large variability in accuracy. The high-level calibrator proved effective, reducing the inter-assay CV from 42.0% (unstandardized) to 14.0%, compared to 17.6% with the two-leveled set. The calibrator passed international homogeneity criteria and was assigned a value of 9.07 ± 0.24 nmol/L.ConclusionsWe established a framework for future PT to enable laboratory accreditation, which is essential to ensure quality of hepcidin measurement and its use in patient care. Additionally, we showed optimized standardization is possible by extending the current sRM with a third high calibrator, although international implementation of the sRM is a prerequisite for its success.

COVID-19 Associated Coagulopathy in an Indian Scenario: A Correlation with Disease Severity and Survival Status

“…The PT was greater than 16.5 secs in 13.5% of total cases and in 35.1% of the non-survivors. This finding was consistent with other studies on Chinese cohort [ 13 , 19 , 22 , 28 ]. Shiyu Yin [ 18 ] reported PT was increased in Covid-19 patients compared to controls.…”

“…The mean age in the non survivors were more than in survivor group highlighting that the disease is more severe in the elderly, who usually have associated comorbidities and succumb to the illness. This was similar to findings in other studies [ 7 , 19 , 22 , 24 , 26 , 27 ]. There was no significant difference in mean age among males and females in the present study.…”

“…The male to female ratio was 1.5: 1. Male were seen to outnumber the females in most of the studies [ 7 , 13 , 22 ].…”

“…Current research on coagulopathy in Covid-19 is mainly dominated by Chinese cohort but data on people of other races, especially from Indians are scarce. Studies on Chinese population have shown D dimer levels are elevated while Platelet counts and PT are usually normal [ 18 – 22 ].…”

Differentiating iron-loading anemias using a newly developed and analytically validated ELISA for human serum erythroferrone

“…However, none is yet routinely available [23] and solely used for research. Our experience in developing assays for the iron-related measurements [24][25][26][27][28][29] has taught us the importance of validation and standardization before using an assay in clinical practice [30][31][32]. Full analytical characterization of an assay ensures correct utilization (fit-for-purpose) of the method and appropriate interpretation of the data, as it reveals the assay's limitations and therefore defines proper methodology to produce reliable results for diagnostic and research purposes [33].…”