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.

Type 1 diabetes mellitus (T1DM) is associated with chronic complications, which are the result of neurovascular changes. There is still a lack of universal biochemical markers of microvascular damage. The present study aimed to investigate whether selected inflammatory proteins are related to the prevalence of microvascular complications in adult T1DM patients. The following markers were determined in a group of 100 T1DM participants: epidermal growth factor (EGF), metalloproteinase 2 (MMP-2), growth/differentiation factor 15 (GDF-15), and interleukin 29 (IL-29). Screening for microvascular complications, such as autonomic and peripheral neuropathy, diabetic kidney disease, and retinopathy, was conducted. The group was divided according to the occurrence of microvascular complications. At least one complication was required for the patient to be included in the microangiopathy group. The median EGF concentration in the microangiopathy group was higher than in the group without microangiopathy (p = 0.03). Increasing EGF concentration was a statistically significant predictor of the presence of microangiopathy in multivariate logistic regression analysis (p < 0.0001). Additionally, a higher GDF-15 level was associated with diabetic kidney disease, peripheral neuropathy, and proliferative retinopathy vs. nonproliferative retinopathy. GDF-15 concentration correlated negatively with estimated glomerular filtration rate (eGFR) (r = −0.28; p = 0.02). To conclude, higher EGF concentration is an independent predictor of the presence of microvascular complications in T1DM patients. Besides the relation between GDF-15 and diabetic kidney disease, it may be also associated with peripheral neuropathy and retinopathy.

Obesity is a chronic and complex disease associated with metabolic, organ and endocrine complications. In the study, we analyzed a group of 105 patients suffering from obesity without any other previously recognized serious disorders who had been referred to a single endocrine center. The study aimed to assess the prevalence of selected organ and endocrine complications by subdividing the group, firstly according to body mass index (BMI) and secondly with regard to metabolic syndrome (MetS), pre-MetS and the metabolically healthy obesity (MHO) category. We have observed that in our groups, the prevalence of hyperlipidemia, hypertension, asthma, obstructive sleep apnea (OSA) depended on BMI category, whereas the incidence of hyperlipidemia, hypertension, OSA, hypothyroidism, non-alcoholic fatty liver disease, prediabetes, and type 2 diabetes was related to the metabolic category. We concluded that the distribution of particular organ and endocrine complications change significantly with increased BMI and with the shift from MHO to pre-MetS and MetS. Thus, to determine the risk of organ and endocrine complications more effectively, BMI and metabolic status should be assessed during the examination of patients with obesity.

Complete blood count is one of the most common diagnostic methods used in everyday practice. Hormonal status is known to affect blood count parameters. The aim of this study is to summarize changes in blood count that may indicate endocrine disorders, based on a literature review. Red cell parameters deteriorate in thyroid disorders including autoimmune thyroiditis and tend to resolve with appropriate treatment implementation. The most frequent form of anaemia associated with thyroid dysfunction is normocytic anaemia. Macrocytic anaemia is more typical of autoimmune thyroiditis-induced hypothyroidism, while microcytic anaemia is more common in hyperthyroidism. Unexplained anaemia or an increase in red cell distribution width should prompt the investigation of thyroid disorders. Cushing's disease may manifest as an increase in white blood cells and platelets. In the blood smear, neutrophilia is often present, while lymphocytes and eosinophils may be within the lower normal range. Hypercortisolism may induce both hyperaemia and anaemia. In hypopituitarism, a decrease in red blood cell count, haemoglobin, haematocrit, and platelets is observed. Acromegaly may be accompanied by an increase in mean corpuscular volume of erythrocytes. Testosterone deficiency is manifested by a decrease in red cell parameters, whereas hyperandrogenism may lead to polycythaemia. In polycystic ovary syndrome an increase in white blood cell count reflects an underlying inflammatory state. Complete blood count analysis is an easily available and cost-effective additional tool in the diagnosis and treatment monitoring of endocrine disorders.

Interleukins play an important role in the development of autoimmune disorders. Interleukin-29, abbreviated IL-29, is also called interferon lambda 1, abbreviated IFN-λ1. This protein is quite a new member of the recently discovered interferon lambda (IFN-λ) family. IL-29 is known to play a strong antiviral role. 1 However, dendritic cells and macrophages produce IL-29 during a wide range of autoimmune disorders without any underlying viral infection during pathogenesis. 2 Elevated IL-29 concentrations were found in diseases with autoimmune aetiology, such as Sjögren's syndrome, rheumatoid arthritis, systemic sclerosis, systemic lupus erythematosus and psoriasis. [3][4][5][6][7] The concentration of IL-29 was also evaluated in atopic dermatitis and asthma, where elevated levels were detected. 8,9 Moreover, concentrations of IL-29 were