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Marin MJ, van Wijk XMR, Boothe PD, Harris NS, Winter WE. An Introduction to the Complete Blood Count for Clinical Chemists: Red Blood Cells. J Appl Lab Med 2024; 9:1025-1039. [PMID: 38646908 DOI: 10.1093/jalm/jfae031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 03/06/2024] [Indexed: 04/23/2024]
Abstract
BACKGROUND The most frequently ordered laboratory test worldwide is the complete blood count (CBC). CONTENT In this primer, the red blood cell test components of the CBC are introduced, followed by a discussion of the laboratory evaluation of anemia and polycythemia. SUMMARY As clinical chemists are increasingly tasked to direct laboratories outside of the traditional clinical chemistry sections such as hematology, expertise must be developed. This review article is a dedication to that effort.
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van Wijk XMR, Sanchez Oviol Z, Winter WE, Harris NS, Marin MJ. An Introduction to the Complete Blood Count for Clinical Chemists: Platelets. J Appl Lab Med 2024; 9:833-847. [PMID: 38549553 DOI: 10.1093/jalm/jfae023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 02/12/2024] [Indexed: 07/02/2024]
Abstract
BACKGROUND The most ordered laboratory test worldwide is the complete blood count (CBC). CONTENT In this primer, an introduction to platelet testing in the context of the CBC is provided with a discussion of the laboratory evaluation of platelet abnormalities including thrombocytopenia and thrombocytosis. SUMMARY As clinical chemists continue to be tasked to direct laboratories outside of the traditional clinical chemistry sections such as hematology, expertise must be developed. This primer is dedicated to that effort.
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Marin MJ, Osa-Andrews B, Maher PA, Wasserfall C, Winter WE, Muzwagi AB, Harris NS. A Hemoglobinopathy That Produces an Array of Different Hemoglobin A1c Values. J Hematol 2024; 13:99-103. [PMID: 38993739 PMCID: PMC11236361 DOI: 10.14740/jh1268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 04/23/2024] [Indexed: 07/13/2024] Open
Abstract
Hemoglobin A1c (HbA1c) refers to non-enzymatically glycated hemoglobin and reflects the patient's glycemic status over approximately 3 months. An elevated HbA1c over 6.5% National Glycohemoglobin Standardization Program (NGSP) (48 mmol/mol the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC)) can be used to diagnose diabetes mellitus. In our laboratory, HbA1c is determined by ion-exchange chromatography which has the advantage of detecting common Hb variants such as Hb S, C, E and D without adversely affecting the HbA1c determination. Certain homozygous or compound heterozygous hemoglobinopathies such as homozygous sickle disease and Hb SC disease can significantly lower the HbA1c by reducing red cell lifespan. Occasionally however, rare and mostly benign hemoglobinopathies can interfere with this technique resulting in an apparent elevation of HbA1c in an otherwise non-diabetic patient. In this report, we describe such a hemoglobinopathy termed Hb Wayne that resulted in a significant HbA1c elevation in a normoglycemic individual. HbA1c was determined by multiple methods including immunoassay, a modified capillary electrophoresis and an alternative ion-exchange system. These techniques yielded significantly lower A1c results, more in keeping with the patient's clinical background. The alternative ion-exchange system resulted in a low A1c that was qualified by warning flags on the chromatogram that indicated the result was not reportable. The hemoglobinopathy in question, Hb Wayne, is a frameshift mutation in the alpha globin gene that results in an extended alpha globin polypeptide that can form two variants Hb Wayne I and Wayne II. Hb Wayne is a clinically silent asymptomatic disorder with no hematologic consequences. The artifactual elevation of HbA1c is, in contrast, very significant because it may result in a misdiagnosis of diabetes mellitus leading to unnecessary treatment. In this report, we compare our findings with other descriptions of Hb Wayne in the literature and corroborate a number of previous observations and conclusions.
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Kubota-Mishra E, Huang X, Minard CG, Astudillo M, Refaey A, Montes G, Sisley S, Ram N, Winter WE, Naylor RN, Balasubramanyam A, Redondo MJ, Tosur M. High Prevalence of A-β+ Ketosis-Prone Diabetes in Children with Type 2 Diabetes and Diabetic Ketoacidosis at Diagnosis: Evidence from the Rare and Atypical Diabetes Network (RADIANT). Pediatr Diabetes 2024; 2024:5907924. [PMID: 38765897 PMCID: PMC11100136 DOI: 10.1155/2024/5907924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/22/2024] Open
Abstract
Background A-β+ ketosis-prone diabetes (KPD) in adults is characterized by presentation with diabetic ketoacidosis (DKA), negative islet autoantibodies, and preserved β-cell function in persons with a phenotype of obesity-associated type 2 diabetes (T2D). The prevalence of KPD has not been evaluated in children. We investigated children with DKA at "T2D" onset and determined the prevalence and characteristics of pediatric A-β+ KPD within this cohort. Methods We reviewed the records of 716 children with T2D at a large academic hospital and compared clinical characteristics of those with and without DKA at onset. In the latter group, we identified patients with A-β+ KPD using criteria of the Rare and Atypical Diabetes Network (RADIANT) and defined its prevalence and characteristics. Results Mean age at diagnosis was 13.7 ± 2.4 years: 63% female; 59% Hispanic, 29% African American, 9% non-Hispanic White, and 3% other. Fifty-six (7.8%) presented with DKA at diagnosis and lacked islet autoantibodies. Children presenting with DKA were older and had lower C-peptide and higher glucose concentrations than those without DKA. Twenty-five children with DKA (45%) met RADIANT A-β+ KPD criteria. They were predominantly male (64%), African American or Hispanic (96%), with substantial C-peptide (1.3 ± 0.7 ng/mL) at presentation with DKA and excellent long-term glycemic control (HbA1c 6.6% ± 1.9% at follow-up (median 1.3 years postdiagnosis)). Conclusions In children with a clinical phenotype of T2D and DKA at diagnosis, approximately half meet criteria for A-β+ KPD. They manifest the key characteristics of obesity, preserved β-cell function, male predominance, and potential to discontinue insulin therapy, similar to adults with A-β+ KPD.
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Redondo MJ, Harrall KK, Glueck DH, Tosur M, Uysal S, Muir A, Atkinson EG, Shapiro MR, Yu L, Winter WE, Weedon M, Brusko TM, Oram R, Vehik K, Hagopian W, Atkinson MA, Dabelea D. Diabetes Study of Children of Diverse Ethnicity and Race: Study design. Diabetes Metab Res Rev 2024; 40:e3744. [PMID: 37888801 PMCID: PMC10939959 DOI: 10.1002/dmrr.3744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 08/16/2023] [Accepted: 10/03/2023] [Indexed: 10/28/2023]
Abstract
AIMS Determining diabetes type in children has become increasingly difficult due to an overlap in typical characteristics between type 1 diabetes (T1D) and type 2 diabetes (T2D). The Diabetes Study in Children of Diverse Ethnicity and Race (DISCOVER) programme is a National Institutes of Health (NIH)-supported multicenter, prospective, observational study that enrols children and adolescents with non-secondary diabetes. The primary aim of the study was to develop improved models to differentiate between T1D and T2D in diverse youth. MATERIALS AND METHODS The proposed models will evaluate the utility of three existing T1D genetic risk scores in combination with data on islet autoantibodies and other parameters typically available at the time of diabetes onset. Low non-fasting serum C-peptide (<0.6 nmol/L) between 3 and 10 years after diabetes diagnosis will be considered a biomarker for T1D as it reflects the loss of insulin secretion ability. Participating centres are enrolling youth (<19 years old) either with established diabetes (duration 3-10 years) for a cross-sectional evaluation or with recent onset diabetes (duration 3 weeks-15 months) for the longitudinal observation with annual visits for 3 years. Cross-sectional data will be used to develop models. Longitudinal data will be used to externally validate the best-fitting model. RESULTS The results are expected to improve the ability to classify diabetes type in a large and growing subset of children who have an unclear form of diabetes at diagnosis. CONCLUSIONS Accurate and timely classification of diabetes type will help establish the correct clinical management early in the course of the disease.
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Winter WE, Harris NS. Iron Biology - An Overview for Laboratorians. ANNALS OF CLINICAL AND LABORATORY SCIENCE 2023; 53:681-695. [PMID: 37945025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
Iron serves a critical role in many metabolic processes, including oxygen delivery (e.g., hemoglobin) and oxygen utilization for the generation of ATP (e.g., cytochromes). Disorders of iron metabolism are best recognized and evaluated in the context of iron's absorption, transportation, monitoring, cellular uptake, and recycling. This review highlights these processes so that disorders of iron deficiency and iron excess can be better understood. Key players in iron metabolism will be highlighted, such as hepcidin, ferroportin, erythroferrone, transferrin, ferritin, HFE, and the transferrin receptors.
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Marin MJ, Mathew CM, Rajasekhar A, Zumberg M, Euliano TY, Winter WE, Pelletier JPR, Pruitt HD, Harris NS. Dysfibrinogenemia: discrepant results following infusion of purified fibrinogen. Blood Coagul Fibrinolysis 2023:00001721-990000000-00085. [PMID: 37395199 DOI: 10.1097/mbc.0000000000001237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Inherited dysfibrinogenemias are molecular disorders of fibrinogen that affect fibrin polymerization. The majority of cases are asymptomatic, but a significant proportion suffer from increased bleeding or thrombosis. We present two unrelated cases of dysfibrinogenemia, both of whom showed a characteristic discrepancy between fibrinogen activity and the immunologic fibrinogen. In one patient, the dysfibrinogenemia was confirmed by molecular analysis; in the other case, the diagnosis was presumptive based upon laboratory studies. Both patients underwent elective surgery. Both received a highly purified fibrinogen concentrate preoperatively and demonstrated a suboptimal laboratory response to the infusion. Three methods for determining fibrinogen concentration (Clauss fibrinogen, prothrombin-derived fibrinogen, and the viscoelastic functional fibrinogen) were utilized in the case of one patient, and these techniques showed discrepant results with the classic Clauss method giving the lowest concentration. Neither patient experienced excessive bleeding during surgery. Although these discrepancies have been previously described in untreated patients, their manifestation after infusion of purified fibrinogen is less well appreciated.
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Marzinotto I, Pittman DL, Williams AJK, Long AE, Achenbach P, Schlosser M, Akolkar B, Winter WE, Lampasona V. Islet Autoantibody Standardization Program: interlaboratory comparison of insulin autoantibody assay performance in 2018 and 2020 workshops. Diabetologia 2023; 66:897-912. [PMID: 36759347 PMCID: PMC10036445 DOI: 10.1007/s00125-023-05877-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 12/21/2022] [Indexed: 02/11/2023]
Abstract
AIMS/HYPOTHESIS The Islet Autoantibody Standardization Program (IASP) aims to improve the performance of immunoassays measuring autoantibodies in type 1 diabetes and the concordance of results across laboratories. IASP organises international workshops distributing anonymised serum samples to participating laboratories and centralises the collection and analysis of results. In this report, we describe the results of assays measuring IAA submitted to the IASP 2018 and 2020 workshops. METHODS The IASP distributed uniquely coded sera from individuals with new-onset type 1 diabetes, multiple islet autoantibody-positive individuals, and diabetes-free blood donors in both 2018 and 2020. Serial dilutions of the anti-insulin mouse monoclonal antibody HUI-018 were also included. Sensitivity, specificity, area under the receiver operating characteristic curve (ROC-AUC), partial ROC-AUC at 95% specificity (pAUC95) and concordance of qualitative/quantitative results were compared across assays. RESULTS Results from 45 IAA assays of seven different formats and from 37 IAA assays of six different formats were submitted to the IASP in 2018 and 2020, respectively. The median ROC-AUC was 0.736 (IQR 0.617-0.803) and 0.790 (IQR 0.730-0.836), while the median pAUC95 was 0.016 (IQR 0.004-0.021) and 0.023 (IQR 0.014-0.026) in the 2018 and 2020 workshops, respectively. Assays largely differed in AUC (IASP 2018 range 0.232-0.874; IASP 2020 range 0.379-0.924) and pAUC95 (IASP 2018 and IASP 2020 range 0-0.032). CONCLUSIONS/INTERPRETATION Assay formats submitted to this study showed heterogeneous performance. Despite the high variability across laboratories, the in-house radiobinding assay (RBA) remains the gold standard for IAA measurement. However, novel non-radioactive IAA immunoassays showed a good performance and, if further improved, might be considered valid alternatives to RBAs.
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Peck Palmer OM, Pyle-Eilola AL, Bertholf RL, Winter WE. 2022 AACC Preanalytical Phase Conference Abstracts. J Appl Lab Med 2023; 8:655-659. [PMID: 36970886 DOI: 10.1093/jalm/jfad015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 03/06/2023] [Indexed: 03/29/2023]
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Harris NS, Marin MJ, Winter WE. What Is the True HbA1c? A HbA1C Peak in the Absence of HbA in an Adult Patient without Sickle Cell Disease. J Appl Lab Med 2023; 8:425-428. [PMID: 36495140 DOI: 10.1093/jalm/jfac125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Knezevic CE, Das B, El-Khoury JM, Jannetto PJ, Lacbawan F, Winter WE. Rising to the Challenge: Shortages in Laboratory Medicine. Clin Chem 2022; 68:1486-1492. [DOI: 10.1093/clinchem/hvac179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 09/28/2022] [Indexed: 11/13/2022]
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Marin MJ, Schwietert MM, Winter WE, Beal SG, Harris NS. Sweet Sphere of Influence. Clin Chem 2022; 68:736-737. [DOI: 10.1093/clinchem/hvab224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 09/24/2021] [Indexed: 11/14/2022]
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Winter WE, Pittman DL, Jialal I. Practical Clinical Applications of Islet Autoantibody Testing in Type 1 Diabetes. J Appl Lab Med 2022; 7:197-205. [PMID: 34996067 DOI: 10.1093/jalm/jfab113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/09/2021] [Indexed: 12/26/2022]
Abstract
BACKGROUND The distinction between type 1 diabetes (T1D) and type 2 diabetes (T2D) is extremely important for the choice of therapy, body weight and dietary management, screening for coexistent autoimmune diseases and comorbidities, anticipated prognosis, and risk assessment in relatives. Not uncommonly, the presentation of the patient may not allow an unambiguous discrimination between T1D and T2D. To help resolve this challenge, the detection of islet autoantibodies can support the diagnosis of T1D. CONTENT The presence of islet autoantibodies in a person with diabetes indicates an autoimmune etiology therefore establishing the diagnosis of T1D. Presently 5 islet autoantibodies are available for routine clinical use: islet cell cytoplasmic autoantibodies (ICA), insulin autoantibodies (IAA), glutamic acid decarboxylase autoantibodies (GADA), insulinoma associated-2 autoantibodies (IA-2A), and zinc transporter-8 autoantibodies (ZnT8A). There are caveats to the selection of which islet autoantibodies should be measured. Islet autoantibodies can also predict the development of T1D. Therefore, once safe and effective therapies are available to prevent T1D, islet autoantibody testing is expected to become a routine part of medical practice. A very rare cause of autoimmune diabetes is the type B insulin resistance syndrome resulting from antagonistic autoantibodies to the insulin receptor. Rarely hypoglycemia can result from agonistic insulin receptor autoantibodies, or high-titer IAA causing the autoimmune insulin syndrome (i.e., Hirata disease). SUMMARY In summary, autoimmune causes of dysglycemia are increasing in clinical importance requiring the scrutiny of laboratorians. The determination of islet autoantibodies can greatly aid in the diagnosis and the prediction of T1D.
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Harris NS, Pelletier JP, Marin MJ, Winter WE. Von Willebrand factor and disease: a review for laboratory professionals. Crit Rev Clin Lab Sci 2021; 59:241-256. [DOI: 10.1080/10408363.2021.2014781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Jialal I, Winter WE. Opinion paper: Is the Friedewald equation obsolete? Clin Chim Acta 2020; 514:122-124. [PMID: 33388310 DOI: 10.1016/j.cca.2020.12.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 12/26/2020] [Accepted: 12/28/2020] [Indexed: 01/22/2023]
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Harris NS, Weaver KD, Beal SG, Winter WE. The Interaction between Hb A1C and Selected Genetic Factors in the African American Population in the USA. J Appl Lab Med 2020; 6:167-179. [PMID: 33367812 DOI: 10.1093/jalm/jfaa202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 10/26/2020] [Indexed: 01/03/2023]
Abstract
BACKGROUND The global prevalence of diabetes mellitus has been growing in recent decades and the complications of longstanding type 2 diabetes continue to place a burden on healthcare systems. The hemoglobin A1c (Hb A1c) content of the blood is used to assess an individual's degree of glycemic control averaged over 2 to 3 months. In the USA, diabetes is the seventh leading cause of death. Black, indigenous, people of color (BIPOC) are disproportionately affected by diabetes compared to non-Hispanic whites. There are many reports of interaction of Hb A1c and hematologic conditions that have a high prevalence in the Black population; some of these effects are contradictory and not easily explained. This review attempts to document and categorize these apparently disparate effects and to assess any clinical impact. METHODS Hb A1C can be determined by a variety of techniques including cation-exchange chromatography, electrophoresis, immunoassays, and affinity chromatography. The amount of Hb A1c present in a patient specimen depends not only on blood glucose but is strongly influenced by erythrocyte survival and by structural variations in the globin chains. Sickling hemoglobinopathies are well-represented in the USA in African Americans and the effects of these hemoglobin disorders as well as G6PD deficiency is examined. CONCLUSION Hb A1c measurement should always be performed with a cautious approach. The laboratory scientist should be aware of possible pitfalls in unquestioningly determining Hb A1c without a consideration of hematologic factors, both inherited and acquired. This presents a challenge as often times, the laboratory is not aware of the patient's race.
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Harris NS, Kavesh M, Beal SG, Winter WE, Chui DHK. When Hemoglobin Reported to Be A, S, and F Are Neither A, S, Nor F: A Tale of Two Patients. J Appl Lab Med 2020; 6:543-549. [PMID: 32995874 DOI: 10.1093/jalm/jfaa087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 05/04/2020] [Indexed: 11/13/2022]
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Kim JT, Winter WE, Luo HY, Chui DHK, Harris NS. Interference of Hemoglobin A 1c Due to Hemoglobin Franklin Park. J Appl Lab Med 2019; 3:911-913. [PMID: 31639767 DOI: 10.1373/jalm.2018.026781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Winter WE, Greene DN, Beal SG, Isom JA, Manning H, Wilkerson G, Harris N. Clotting factors: Clinical biochemistry and their roles as plasma enzymes. Adv Clin Chem 2019; 94:31-84. [PMID: 31952574 DOI: 10.1016/bs.acc.2019.07.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The purpose of this review is to describe structure and function of the multiple proteins of the coagulation system and their subcomponent domains. Coagulation is the process by which flowing liquid blood plasma is converted to a soft, viscous gel entrapping the cellular components of blood including red cells and platelets and thereby preventing extravasation of blood. This process is triggered by the minimal proteolysis of plasma fibrinogen. This transforms the latter to sticky fibrin monomers which polymerize into a network. The proteolysis of fibrinogen is a function of the trypsin-like enzyme termed thrombin. Thrombin in turn is activated by a cascade of trypsin-like enzymes that we term coagulation factors. In this review we examine the mechanics of the coagulation cascade with a view to the structure-function relationships of the proteins. We also note that two of the factors have no trypsin like protease domain but are essential cofactors or catalysts for the proteases. This review does not discuss the major role of platelets except to highlight their membrane function with respect to the factors. Coagulation testing is a major part of routine diagnostic clinical pathology. Testing is performed on specimens from individuals either with bleeding or with thrombotic disorders and those on anticoagulant medications. We examine the basic in-vitro laboratory coagulation tests and review the literature comparing the in vitro and in vivo processes. In vitro clinical testing typically utilizes plasma specimens and non-physiological or supraphysiological activators. Because the review focuses on coagulation factor structure, a brief overview of the evolutionary origins of the coagulation system is included.
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Lampasona V, Pittman DL, Williams AJ, Achenbach P, Schlosser M, Akolkar B, Winter WE. Islet Autoantibody Standardization Program 2018 Workshop: Interlaboratory Comparison of Glutamic Acid Decarboxylase Autoantibody Assay Performance. Clin Chem 2019; 65:1141-1152. [PMID: 31409598 DOI: 10.1373/clinchem.2019.304196] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 06/27/2019] [Indexed: 12/31/2022]
Abstract
BACKGROUND The Islet Autoantibody Standardization Program (IASP) aims to improve the performance of immunoassays measuring type 1 diabetes (T1D)-associated autoantibodies and the concordance of results among laboratories. IASP organizes international interlaboratory assay comparison studies in which blinded serum samples are distributed to participating laboratories, followed by centralized collection and analysis of results, providing participants with an unbiased comparative assessment. In this report, we describe the results of glutamic acid decarboxylase autoantibody (GADA) assays presented in the IASP 2018 workshop. METHODS In May 2018, IASP distributed to participants uniquely coded sera from 43 new-onset T1D patients, 7 multiple autoantibody-positive nondiabetic individuals, and 90 blood donors. Results were analyzed for the following metrics: sensitivity, specificity, accuracy, area under the ROC curve (ROC-AUC), partial ROC-AUC at 95% specificity (pAUC95), and concordance of qualitative and quantitative results. RESULTS Thirty-seven laboratories submitted results from a total of 48 different GADA assays adopting 9 different formats. The median ROC-AUC and pAUC95 of all assays were 0.87 [interquartile range (IQR), 0.83-0.89] and 0.036 (IQR, 0.032-0.039), respectively. Large differences in pAUC95 (range, 0.001-0.0411) were observed across assays. Of formats widely adopted, bridge ELISAs showed the best median pAUC95 (0.039; range, 0.036-0.041). CONCLUSIONS Several novel assay formats submitted to this study showed heterogeneous performance. In 2018, the majority of the best performing GADA immunoassays consisted of novel or established nonradioactive tests that proved on a par or superior to the radiobinding assay, the previous gold standard assay format for GADA measurement.
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Winter WE, Harris NS, Flax S. What Are the Goals of Lipid Testing? J Appl Lab Med 2018; 2:816-818. [DOI: 10.1373/jalm.2016.022939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 08/22/2017] [Indexed: 11/06/2022]
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Winter WE, Jacobsen LM, Pittman D. Insulin, insulin antibodies and insulin autoantibodies. MLO: MEDICAL LABORATORY OBSERVER 2017; 49:16-18. [PMID: 30005474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
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Peters AL, Ahmann AJ, Battelino T, Evert A, Hirsch IB, Murad MH, Winter WE, Wolpert H. Diabetes Technology-Continuous Subcutaneous Insulin Infusion Therapy and Continuous Glucose Monitoring in Adults: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab 2016; 101:3922-3937. [PMID: 27588440 DOI: 10.1210/jc.2016-2534] [Citation(s) in RCA: 141] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To formulate clinical practice guidelines for the use of continuous glucose monitoring and continuous subcutaneous insulin infusion in adults with diabetes. PARTICIPANTS The participants include an Endocrine Society-appointed Task Force of seven experts, a methodologist, and a medical writer. The American Association for Clinical Chemistry, the American Association of Diabetes Educators, and the European Society of Endocrinology co-sponsored this guideline. EVIDENCE The Task Force developed this evidence-based guideline using the Grading of Recommendations, Assessment, Development, and Evaluation system to describe the strength of recommendations and the quality of evidence. The Task Force commissioned one systematic review and used the best available evidence from other published systematic reviews and individual studies. CONSENSUS PROCESS One group meeting, several conference calls, and e-mail communications enabled consensus. Committees and members of the Endocrine Society, the American Association for Clinical Chemistry, the American Association of Diabetes Educators, and the European Society of Endocrinology reviewed and commented on preliminary drafts of these guidelines. CONCLUSIONS Continuous subcutaneous insulin infusion and continuous glucose monitoring have an important role in the treatment of diabetes. Data from randomized controlled trials are limited on the use of medical devices, but existing studies support the use of diabetes technology for a wide variety of indications. This guideline presents a review of the literature and practice recommendations for appropriate device use.
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MESH Headings
- Adult
- Blood Glucose/analysis
- Combined Modality Therapy/adverse effects
- Combined Modality Therapy/trends
- Consensus
- Diabetes Mellitus, Type 1/blood
- Diabetes Mellitus, Type 1/diet therapy
- Diabetes Mellitus, Type 1/drug therapy
- Diabetes Mellitus, Type 1/therapy
- Diabetes Mellitus, Type 2/blood
- Diabetes Mellitus, Type 2/diet therapy
- Diabetes Mellitus, Type 2/drug therapy
- Diabetes Mellitus, Type 2/therapy
- Diet, Diabetic/adverse effects
- Drug Monitoring/trends
- Endocrinology/methods
- Evidence-Based Medicine
- Exercise
- Humans
- Hyperglycemia/prevention & control
- Hypoglycemia/chemically induced
- Hypoglycemia/prevention & control
- Hypoglycemic Agents/administration & dosage
- Hypoglycemic Agents/adverse effects
- Hypoglycemic Agents/therapeutic use
- Insulin/administration & dosage
- Insulin/adverse effects
- Insulin/therapeutic use
- Insulin Infusion Systems/adverse effects
- Insulin Infusion Systems/trends
- International Agencies
- Monitoring, Ambulatory/adverse effects
- Monitoring, Ambulatory/trends
- Patient Education as Topic
- Precision Medicine
- Societies, Scientific
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