The use of fructosamine in cystic fibrosis-related diabetes (CFRD) screening.

Objective: To determine whether serum fructosamine correlates with glycemic control and clinical outcomes in patients being screened for cystic fibrosis-related diabetes (CFRD).

Methods: Fructosamine and percent predicted forced expiratory volume in 1s (FEV) were measured in patients undergoing a 2h oral glucose tolerance test (OGTT) for CFRD screening. Fractional serum fructosamine (FSF) was calculated as fructosamine/total protein.

Stability of specific IgE antibodies to common food and inhalant allergens.

Objective: To determine the optimum storage temperature for serum allergen specific IgE antibodies (sIgE) to common food and inhalant allergens.

Methods: Patient sera with sIgE concentrations ≥0.7kIU/l were pooled accordingly: pool 1-peanut and hazelnut, pool 2-egg white, cow's milk and cod fish, pool 3-soy, wheat and shrimp and pool 4-dust mite Dermatophagoides farinae, dog dander, cat dander, Timothy grass pollen, and silver birch pollen.

Identification of Hb Wayne and its effects on HbA1c measurement by 5 methods.

Background: The World Health Organization and the American and Canadian Diabetes Associations approved HbA1c >6.5% as diagnostic for type 2 diabetes mellitus (T2DM). Hb variants and/or their chemically modified species can interfere with HbA1c measurements.

A novel double heterozygous Hb Fontainebleau/HbD Punjab hemoglobinopathy.

Objectives: To report the finding of a novel double heterozygous hemoglobinopathy, the coinheritance of Hb Fontainebleau (α-chain variant) with HbD-Punjab (β-chain variant) discovered upon investigation of unexplained microcytosis in an infant.

Design And Methods: Hemoglobinopathy investigation was performed by high performance liquid chromatography (HPLC) using the β-thalassemia Short Program on the Bio-Rad Variant II(TM) followed by gel electrophoresis at alkaline and acid pH (Sebia Hydrasys 2 Electrophoresis System) and molecular diagnostic testing. This study complied with our institutional board ethics requirements.

Incidence of hemoglobinopathies and thalassemias in Northern Alberta. Establishment of reference intervals for HbF and HbA2.

Objectives: The aims of this study were to identify the incidence of hemoglobinopathies and thalassemias in Northern Alberta and calculate the reference intervals (RI) for hemoglobin (Hb) HbF and HbA2.

Methods: A retrospective ad-hoc analysis of the structural Hb variants and thalassemias identified on patients who had a hemoglobinopathy/thalassemia investigation performed between February 1 to December 31, 2013. Results were extracted from the Laboratory Information System.

Current evidence and future perspectives on the effective practice of patient-centered laboratory medicine.

Background: Systematic evidence of the contribution made by laboratory medicine to patient outcomes and the overall process of healthcare is difficult to find. An understanding of the value of laboratory medicine, how it can be determined, and the various factors that influence it is vital to ensuring that the service is provided and used optimally.

Content: This review summarizes existing evidence supporting the impact of laboratory medicine in healthcare and indicates the gaps in our understanding.

Analytical evaluation of the Diazyme glycated serum protein assay on the siemens ADVIA 1800: comparison of results against HbA1c for diagnosis and management of diabetes.

Hemoglobin A1c (HbA1c) is considered the gold standard for assessment of glycemic control in diabetic patients. HbA1c is inadequate in individuals homozygous or compound heterozygous for hemoglobin variants or in conditions with an altered red blood cell turnover. In these cases glycated albumin (GA) is proposed as an alternative assay.

The effect of paraproteins and rheumatoid factor on four commercial immunoassays for vancomycin: implications for laboratorians and other health care professionals.

Background: Paraproteins, immunoglobulins (Igs), which are elevated in various autoimmune disorders, are known to interfere with various laboratory immunoassays, including vancomycin (VANC). Rheumatoid factor (RF), a known immunoassay interferant, may cause falsely elevated results.

Objectives: The aims of this study were to (1) evaluate the effect of 3 paraproteins (IgA, IgG, and IgM) on 4 commercial VANC immunoassays [fluorescence polarization immunoassay; enzyme multiplied immunoassay; 2 particle-enhanced turbidimetric inhibition immunoassays]; (2) determine the concentration at which the effect is obtained, and (3) examine the influence of RF on the VANC methods.

Is HbA1c a good screening test for diabetes mellitus?

Objectives: HbA(1c) has been recently recommended as the primary diagnostic test for diabetes. This study evaluated the positive predictive value (PPV) and negative predictive value (NPV) of HbA(1c) against the oral glucose tolerance test (OGTT) in three locations.

Design And Methods: Three years of data with concurrent OGTT and HbA(1c) tests were extracted from Laboratory Information Systems (LIS) and receiver operator (ROC) curves and positive and negative predictive values calculated comparing the OGTT with the HbA(1c) values using a 10% prevalence of diabetes.

Total hCG tests.

Introduction: There are 12 types of automated total hCG tests sold today, the Abbott Architect, Abbott AxSym, the Beckman Access 2. Beckman DxI 800, the Ortho Vitros EciQ, Roche Elecsys hCG+β, Siemens ACS180, Siemens Centaur, Siemens Dimension, Siemens Immulite and Siemens Stratus, and the Tosoh A1A. All tests claim to be total hCG tests but do not define what total means.

The use of serial patient blood gas, electrolyte and glucose results to derive biologic variation: a new tool to assess the acceptability of intensive care unit testing.

Background: Most estimates of biologic variation (s(b)) are based on periodically acquiring and storing specimens, followed by analysis within a single analytic run. We demonstrate for many intensive care unit (ICU) tests, only patient results need be statistically analyzed to provide reliable estimates of s(b).

Methods: Over 11 months, approximately 28,000 blood gas measurements (including electrolyte panels and glucose) were performed on one of two Radiometer ABL800 FLEX analyzers (Radiometer, Copenhagen, Denmark) from 1676 ICU patients.

Use of serial patient hemoglobin A1c differences to determine long-term imprecision of immunoassay and high-performance liquid chromatography analyzers.

Background: The quality of the HbA1c assay is inversely proportional to the variation of the assay. Most published measures of HbA1c variation are limited by the data collection period, the statistical treatment of outliers, and even the noncommutability of the products used to generate the variation measurements. We have used an alternate approach to derive HbA1c variation, using serial patient data.

Quantification of HbA(2) in patients with and without beta-thalassemia and in the presence of HbS, HbC, HbE, and HbD Punjab hemoglobin variants: comparison of two systems.

We studied whether problems quantifying hemoglobin A(2) (HbA(2)) could be resolved by using capillary electrophoresis. HbA(2) was quantified on whole blood samples from patients with and without beta-thalassemia trait and patients heterozygous for HbE, HbS, HbC, and HbD Punjab using the VARIANT II beta-thalassemia (Bio-Rad, Hercules, CA) and Capillarys 2 (Sebia, Norcross, GA). HbA(2) results in patients with and without beta-thalassemia trait were lower with the Capillarys 2 system.

MALDI-TOF MS/microwave-assisted acid hydrolysis identification of HbG Coushatta.

Objective: To evaluate the effectiveness of microwave-assisted acid hydrolysis of proteins combined with MALDI-TOF MS to characterize hemoglobin G Coushatta.

Design And Method: Following separation of the globin chains, the purified beta chain fractions were hydrolyzed by acid hydrolysis prior to MALDI-TOF MS.

Results: The method correctly identified the abnormal amino acid in HbG Coushatta.

Application of 3-D Delta check graphs to HbA1c quality control and HbA1c utilization.

Delta checking is a laboratory information system (LIS)-based tool that detects patient and laboratory quality control errors. By using hemoglobin A1c (HbA1c) data, we developed a novel approach to summarizing and presenting patient Delta values to address limitations of current Delta check algorithms. Delta values were calculated from intrapatient pairs of HbA1c (n = 55,327) measured during 2 years in a single referral or a university hospital laboratory.

QA aspects for HbA1c measurements.

Objectives: To provide mechanisms for evaluating HbA(1c) results that meet the criteria for review by the 2002 NACB guidelines for reporting HbA(1c) values.

Design And Methods: Complete blood count (CBC) data and comparison of obtained HbA(1c) with a calculated HbA(1c) were used to assess the validity of HbA(1c) results meeting the NACB review criteria.

Results: The use of CBC data and a calculated HbA(1c) were found to be useful in evaluating the validity of unusual HbA(1c) results.

Biochemistry testing associated with pregnancy and the newborn period -- a lot has changed since you were a baby!

Everyone has been a newborn, and everyone's mother has been pregnant. Despite the commonality of these events, medical care and the clinical chemistry laboratory's role in it have changed remarkably over the last 50 years. This review is a historical overview of clinical chemistry testing that is related to pregnancy and the newborn period.

Improved resolution of serum bisalbumin on electrophoresis and investigation of bisalbumin in urine.

Objectives: : The aims of this study were to improve the resolution of albumin variants (bisalbumins, especially albumin Naskapi) from albumin in commercial serum protein electrophoresis systems; to compare the separation of bisalbumin from albumin on these improved methods against the recognized gold standard of capillary electrophoresis; and to investigate the presence of albumin variants in urine.

Design And Methods: : Electrophoresis was performed using the Sebia Hydrasys 15/30 beta1beta2 system, as well as modified methods on the Sebia Hydrasys HR and the Beckman Paragon systems. The interpretation of electrophoretic gels was performed by manual visualization and densitometric scanning.

Tentative identification of hemoglobin variants in the Bio-Rad VARIANT II Hb A1C method.

Objective: To evaluate if peak characteristics, the retention time, and percentage of total hemoglobin of an unknown peak on the Bio-Rad VARIANT II Hb A1c method may be used to establish a tentative identification of hemoglobin variants.

Method: The peak characteristics, retention time, and percentage of total hemoglobin obtained on abnormal peaks found on the Bio-Rad VARIANT II Hb A1c method were tabulated and evaluated against the identification of the hemoglobin variant established by the Bio-Rad beta thalassemia HPLC method and hemoglobin electrophoresis at both acid and alkaline pH.

Results: Some hemoglobin variants show specific peak characteristics, retention times, and percentage of total hemoglobin on the Bio-Rad VARIANT II Hb A1c method that allows for tentative identification of the hemoglobin variant.

Between-method variation in human chorionic gonadotropin test results.

Background: Results on sera and calibrators vary 1.4- to 2.3-fold among commercial human chorionic gonadotropin (hCG) assays.

Measurement of inaccuracy and imprecision of HCG methods using dilutions of the WHO 4th IS-HCG standard and a pregnant patient's serum.

Introduction: Differences in human chorionic gonadotropin (hCG) results obtained by seven different methods were documented by analyzing dilutions of the WHO 4th International Standard (IS) and a pregnant patient's serum.

Materials And Methods: Biases of +30.9 to -37.