Objectives: Artifactually altered glycated hemoglobin (HbA(1c)) concentrations are frequently linked to hemoglobin (Hb) variants. Their expression and detection require in-depth analysis.Methods:... Show moreObjectives: Artifactually altered glycated hemoglobin (HbA(1c)) concentrations are frequently linked to hemoglobin (Hb) variants. Their expression and detection require in-depth analysis.Methods: Cation exchange high performance liquid chromatography (HPLC) (Bio-Rad Variant (TM) II; Trinity Biotech Premier Hb9210 Resolution), capillary electrophoresis (CE) (Sebia Capillarys 2 Flex Piercing) and mass spectrometry (MS) (Waters) were used for variant detection; Sanger sequencing, multiplex ligation-dependent probe amplification (MLPA) and next generation sequencing (NGS) were used for DNA analysis; HbA(1c) was measured with cation exchange HPLC (Bio-Rad Variant (TM) II; Arkray Adams HA-8180V; Tosoh HLC-723 G7), CE (Sebia Capillarys 2 Flex Piercing), boronate affinity HPLC (Trinity Biotech Hb9210 Premier), immunoassay (Cobas c501 Tina-quant HbA(1c) Gen. 3; Nihon Kohden CHM-4100 Celltac chemi HbA(1c) HA-411V) and enzymatic assay (Abbott Architect c 8000 HbA(1c)).Results: Hb Yamagata [beta 132(H10)Lys -> Asn; (HBB: c.399A>T)] was identified in the proband by MS after the observation of an abnormal peak in HPLC and CE. A mosaic expression of this variant was detected by NGS (mutant: 8%; wild type: 92%), after negative results in Sanger sequencing. Hb Yamagata interfered with HbA(1c) measurements by cation exchange HPLC and CE whereas immuno and enzymatic assay values showed good agreement with boronate affinity HPLC measurement.Conclusions: A mosaicism of Hb Yamagata was found in a patient with altered HbA(1c) values. This rare gene variant was detected only by advanced technologies as MS and NGS. The variant interfered with common HbA(1c) determination methods. Show less
Objectives: COVID-19 is an ongoing global pandemic. There is an urgent need for identification and understanding of clinical and laboratory parameters related to progression towards a severe and... Show moreObjectives: COVID-19 is an ongoing global pandemic. There is an urgent need for identification and understanding of clinical and laboratory parameters related to progression towards a severe and fatal form of this illness, often preceded by a so-called cytokine-storm syndrome (CSS). Therefore, we explored the hemocytometric characteristics of COVID-19 patients in relation to the deteriorating clinical condition CSS, using the Sysmex XN-10 hematology analyzer.Methods: From March 1st till May 16th, 2020, all patients admitted to our hospital with respiratory complaints and suspected for COVID-19 were included (n=1,140 of whom n=533 COVID-19 positive). The hemocytometric parameters of immunocompetent cells in peripheral blood (neutrophils [NE], lymphocytes [LY] and monocytes [MO]) obtained upon admission to the emergency department (ED) of COVID-19 positive patients were compared with those of the COVID-19 negative ones. Moreover, patients with CSS (n=169) were compared with COVID-19 positive patients without CSS, as well as with COVID-19 negative ones.Results: In addition to a significant reduction in leukocytes, thrombocytes and absolute neutrophils, it appeared that lymphocytes-forward scatter (LY-FSC), and reactive lymphocytes (RE-LYMPHO)/leukocytes were higher in COVID-19-positive than negative patients. At the moment of presentation, COVID-19 positive patients with CSS had different neutrophils- side fluorescence (NE-SFL), neutrophils-forward scatter (NE-FSC), LY-FSC, RE-LYMPHO/lymphocytes, antibody-synthesizing (AS)-LYMPHOs, high fluorescence lymphocytes (HFLC), MO-SSC, MO-SFL, and Reactive (RE)-MONOs. Finally, absolute eosinophils, basophils, lymphocytes, monocytes and MO-FSC were lower in patients with CSS.Conclusions: Hemocytometric parameters indicative of changes in immunocompetent peripheral blood cells and measured at admission to the ED were associated with COVID-19 with and without CSS. Show less
Bank, P.C.D.; Jacobs, L.H.J.; Berg, S.A.A. van den; Deutekom, H.W.M. van; Hamann, D.; Molenkamp, R.; ... ; Oosterhuis, W.P. 2021
The in vitro diagnostic medical devices regulation (IVDR) will take effect in May 2022. This regulation has a large impact on both the manufacturers of in vitro diagnostic medical devices (IVD) and... Show moreThe in vitro diagnostic medical devices regulation (IVDR) will take effect in May 2022. This regulation has a large impact on both the manufacturers of in vitro diagnostic medical devices (IVD) and clinical laboratories. For clinical laboratories, the IVDR poses restrictions on the use of laboratory developed tests (LDTs). To provide a uniform interpretation of the IVDR for colleagues in clinical practice, the IVDR Task Force was created by the scientific societies of laboratory specialties in the Netherlands. A guidance document with explanations and interpretations of relevant passages of the IVDR was drafted to help laboratories prepare for the impact of this new legislation. Feedback from interested parties and stakeholders was collected and used to further improve the document. Here we would like to present our approach to our European colleagues and inform them about the impact of the IVDR and, importantlywewould like to present potentially useful approaches to fulfill the requirements of the IVDR for LDTs. Show less
![Hemoglobin Yamagata [beta 132(H10)Lys -> Asn; (HBB: c.399A > T)]: a mosaic to be put together](/sites/all/modules/custom/islandora_solr_search/images/defaultimg.png?solr_nav%5Bid%5D=a2b162ec7726ef3579f0&solr_nav%5Bpage%5D=0&solr_nav%5Boffset%5D=0)
