A comparative analysis of current С-peptide assays compared to a reference method: can we overcome inertia to standardization?

Objectives: C-peptide is an equimolar by-product of insulin biosynthesis. It is used clinically to assess insulin secretion and differentiate types of diabetes. However, the lack of standardization across assays limits its broader application.

Commercial Immunoglobulin Products Contain Neutralizing Antibodies Against Severe Acute Respiratory Syndrome Coronavirus 2 Spike Protein.

Background: Patients with antibody deficiency respond poorly to coronavirus disease 2019 (COVID-19) vaccination and are at risk of severe or prolonged infection. They are given long-term immunoglobulin replacement therapy (IRT) prepared from healthy donor plasma to confer passive immunity against infection. Following widespread COVID-19 vaccination alongside natural exposure, we hypothesized that immunoglobulin preparations will now contain neutralizing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike antibodies, which confer protection against COVID-19 disease and may help to treat chronic infection.

Evaluation of interference from hemoglobin C, D, E and S traits on measurements of hemoglobin A1c by fifteen methods.

Background: Hemoglobin C, D Punjab, E or S trait can interfere with hemoglobin A1c (HbA1c) results. We assessed whether they affect results obtained with 15 current assay methods.

Methods: Hemoglobin AA (HbAA), HbAC, HbAD Punjab, HbAE and HbAS samples were analyzed on 2 enzymatic, 4 ion-exchange HPLC and 9 immunoassay methods.

Publisher Correction: Whole-genome sequencing of a sporadic primary immunodeficiency cohort.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Effects of hemoglobin C, D, E and S traits on measurements of hemoglobin A1c by twelve methods.

Background: Hemoglobin C, D Punjab, E or S trait can interfere with hemoglobin A1c (HbA1c) results. We assessed whether they affect results obtained with 12 current assay methods.

Methods: Hemoglobin AA (HbAA), HbAC, HbAD Punjab, HbAE and HbAS samples were analyzed on one enzymatic, nine ion-exchange HPLC and two Capillary Electrophoresis methods.

Evaluation of hemoglobin A1c measurement by Capillarys 2 electrophoresis for detection of abnormal glucose tolerance in African immigrants to the United States.

Background: Hemoglobin A1c (HbA1c) is used to monitor long-term glycemic control in individuals with diabetes, guide therapy, predict the risk of microvascular complications, and more recently to diagnose diabetes. An automated liquid-flow capillary electrophoresis method was recently developed to measure HbA1c using the Capillarys 2 Flex Piercing instrument.

Methods: Analytical evaluation was performed at 2 clinical centers.

Effects of 49 Different Rare Hb Variants on HbA1c Measurement in Eight Methods.

Background: Previous studies have shown interference with HbA1c measurement from the 4 most common heterozygous Hb variants (HbAS, HbAE, HbAC, and HbAD) with some assay methods. Here we examine analytical interference from 49 different less common variants with 7 different HbA1c methods using various method principles.

Methods: Hb variants were screened using the Bio-Rad Variant or Variant II beta thal short program, confirmed by alkaline and acid electrophoresis, and identified by sequence analysis.

Pseudomonas infection in antibody deficient patients.

Pseudomonas aeruginosa (PA) is commonly isolated from the respiratory secretions of antibody deficiency patients, but the significance of this has not been well studied. We have reviewed our adult antibody deficiency cohort of 179 patients and assessed the prevalence and characteristics of PA infection and the effects of early antibiotic eradication treatments. Of the 34 patients with PA, 55.

Novel NFKB2 mutation in early-onset CVID.

Common variable immunodeficiency (CVID) is heterogeneous, clinically, immunologically and genetically. The majority of genetic mechanisms leading to CVID remain elusive. We studied a Greek Cypriot family of non-consanguineous parents.

Measurement of Hba(1C) in patients with chronic renal failure.

Background: Carbamylated hemoglobin (carbHb) is reported to interfere with measurement and interpretation of HbA(1c) in diabetic patients with chronic renal failure (CRF). There is also concern that HbA1c may give low results in these patients due to shortened erythrocyte survival.

Methods: We evaluated the effect of carbHb on HbA(1c) measurements and compared HbA(1c) with glycated albumin (GA) in patients with and without renal disease to test if CRF causes clinically significant bias in HbA(1c) results by using 11 assay methods.

Effects of whole blood storage on hemoglobin a1c measurements with five current assay methods.

Background: Hemoglobin A1c (HbA1c) is an important index of average glycemia in patients with diabetes mellitus that is widely used in clinical trials and large-scale epidemiological studies. Previous studies have shown that adverse sample storage conditions can cause erroneous HbA1c results. We examined the effect of storage at different temperatures with five current HbA1c methods: Tosoh G7 and G8 (Tosoh Bioscience, Inc.

Factor H facilitates the clearance of GBM bound iC3b by controlling C3 activation in fluid phase.

Dense deposit disease (DDD) is strongly associated with the uncontrolled activation of the complement alternative pathway. Factor H (CFH)-deficient (Cfh(-/-)) mice spontaneously develop C3 deposition along the glomerular basement membrane (GBM) with subsequent development of glomerulonephritis with features of DDD, a lesion dependent on C3 activation. In order to understand the role of CFH in preventing renal damage associated with the dysregulation of the alternative pathway we administered purified mouse CFH (mCFH) to Cfh(-/-) mice.

The effect of elevated fetal hemoglobin on hemoglobin A1c results: five common hemoglobin A1c methods compared with the IFCC reference method.

Hemoglobin A1c (HbA1c) is an important indicator of risk for complications in patients with diabetes mellitus. Elevated fetal hemoglobin (HbF) levels have been reported to interfere with results of some HbA1c methods, but it has generally been assumed that HbA1c results from boronate-affinity methods are not affected by elevated HbF levels. None of the previous studies used the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) reference method as the comparative HbA1c method.

Stat3 is involved in control of MASP2 gene expression.

Little is known about determinants regulating expression of Mannan-binding lectin associated serine protease-2 (MASP-2), the effector component of the lectin pathway of complement activation. Comparative bioinformatic analysis of the MASP2 promoter regions in human, mouse, and rat, revealed conservation of two putative Stat binding sites, termed StatA and StatB. Site directed mutagenesis specific for these sites was performed.

Radiographic evaluation of the Zurich cementless total hip acetabular component.

Objective: To radiographically evaluate the Zurich cementless total hip (ZCTH) cup and correlate lucency with clinical signs of implant instability, time since surgery, and implant generation, using zonal analysis.

Study Design: Retrospective study.

Animals: Client-owned dogs (n = 53).

Organization of the MASP2 locus and its expression profile in mouse and rat.

The mouse, rat, and human MASP2 loci are situated on syntenic chromosome regions and are highly conserved. They comprise the genes for MASP-2/ MAp19, TAR DNA binding protein of 43 kDa, FRAP kinase, CDT6, Polymyositis-Scleroderma 100-kDa autoantigen, spermidine synthase, and TERE which were analyzed by annotation of available gene transcript data and cross-species comparison of available genomic sequences. The human and rat genes for spermidine synthase have an additional intron compared to the mouse gene.