A guide to conducting systematic reviews of clinical laboratory tests.

Clinical laboratory professionals have an instrumental role in supporting clinical decision making with the optimal use of laboratory testing for screening, risk stratification, diagnostic, prognostic, treatment selection and monitoring of different states of health and disease. Delivering evidence-based laboratory medicine relies on review of available data and literature. The information derived, supports many national policies to improve patient care through clinical practice guidelines or best practice recommendations.

Analytical Concordance of Diverse Point-of-Care and Central Laboratory Troponin I Assays.

Background: Cardiac troponin I (cTnI) 99th percentile cutoffs, used in the diagnosis of acute myocardial infarction, are not standardized across cTnI assays. We compared 3 point-of-care (POC) and 1 central laboratory contemporary cTnI assays against the Abbott high-sensitivity (hs) cTnI to evaluate the analytical concordance and the feasibility of using a single cutoff value for all assays.

Methods: Fresh blood samples collected from 102 inpatients in the coronary care unit were measured on central laboratory instruments (Beckman Coulter DxI AccuTnI+3 TnI, Abbott Architect hs-TnI) and cTnI POC analyzers (Alere Triage Troponin I, Radiometer AQT90, Abbott i-STAT).

Point-of-care testing (POCT) and evidence-based laboratory medicine (EBLM) - does it leverage any advantage in clinical decision making?

Point-of-care testing (POCT) is the analysis of patient specimens outside the clinical laboratory, near or at the site of patient care, usually performed by clinical staff without laboratory training, although it also encompasses patient self-monitoring. It is able to provide a rapid result near the patient and which can be acted upon immediately. The key driver is the concept that clinical decision making may be delayed when samples are sent to the clinical laboratory.

Candidate recommendations for protein electrophoresis reporting from the Canadian Society of Clinical Chemists Monoclonal Gammopathy Working Group.

Protein electrophoresis is commonly used as an aid in the diagnosis of monoclonal gammopathies and is performed in many laboratories in Canada and throughout the world. However, unlike many other diagnostic tests, there is limited guidance for standardization and neither guidance nor specific recommendations for clinical reporting of serum (SPE) or urine (UPE) protein electrophoresis and immunotyping available in the literature. Therefore, a Canadian effort was undertaken to recommend standards that cover all aspects of clinical reporting with an ultimate goal towards reporting standardization.

Analytical sensitivity and diagnostic performance of serum protein electrophoresis on the HYDRAGEL 30 PROTEIN(E) β1-β2 Sebia Hydrasys system.

Background: Serum protein electrophoresis (SPE) and immunofixation electrophoresis (IFE) are used in the diagnosis and monitoring of plasma cell dyscrasias. IFE is considered the most sensitive method for the detection of monoclonal proteins (M-proteins), but it is not quantitative. The goal of this study was to establish the analytical sensitivity and diagnostic performance of SPE on the Sebia Hydrasys using HYDRAGEL 30 PROTEIN(E) β1-β2.

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.

Evaluation of thyroid test utilization through analysis of population-level data.

Background: Inappropriate laboratory test utilization can result in unnecessary patient testing and increased healthcare costs. While several thyroid function tests are available, thyroid-stimulating hormone (TSH) is recommended as the first-line test for investigating and monitoring thyroid dysfunction. We evaluate thyroid test utilization in Northern Alberta in terms of testing patterns, frequencies, and reflex cutpoints.

Erroneous HbA1c results in a patient with elevated HbC and HbF.

Background: HbA1c is used in the diagnosis and monitoring of diabetes mellitus (DM). Interference from hemoglobin variants is a well-described phenomenon, particularly with HPLC-based methods. While immunoassays may generate more reliable HbA1c results in the presence of some variants, these methods are susceptible to negative interference from high concentrations of HbF.

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.

Hemoglobin Hirose: A rare beta chain variant causing falsely low HbA1c by HPLC.

Objectives: To investigate the underlying cause of unexpectedly low HbA1c results (3.3-3.5%) obtained by HPLC in three siblings undergoing routine screening for type 2 diabetes mellitus.

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.

Hemoglobin Constant Spring exhibits prolonged ex vivo stability when assessed by HPLC.

Objectives: 1) To investigate the presence of hemoglobin Constant Spring (HbCS) in a patientwith severe microcytic anemia who had previously been diagnosed with alpha thalassemia minor. 2) To assess the stability of HbCS post blood collection by high performance liquid chromatography (HPLC).

Design And Methods: Hemoglobin fractionation was performed by HPLC immediately after specimen collection using the β-thalassemia Short Program on the BioRad Variant II.

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.

Evaluation of a commercially available carbohydrate deficient transferrin kit to detect beta-2-transferrin in cerebrospinal fluid using capillary electrophoresis.

Objective: The aim of this study was to evaluate the CEofix™ CDT Capillary Electrophoresis (CE) kit for the detection of β-2-tranferrin (β-2-Tf) in cerebrospinal fluid (CSF).

Design And Method: Evaluation was performed according to CLSI EP5-A and EP12-A guidelines.

Results: The method resolved β-2-Tf from other Tf isoforms.

Assessment of a four hour delay for urine samples stored without preservatives at room temperature for urinalysis.

Objectives: To determine whether urine storage at room temperature for up to 2h versus 4h changes urinalysis results.

Design And Methods: We compared the rejection rate at eight different hospital laboratories and concordance of urinalysis results (n=83; two laboratories) between urines analyzed within 2h and 4h after collection.

Results: The rejection rate at the two hour cutoff was significantly higher as compared to the four hour cutoff.

Utility of urine myoglobin for the prediction of acute renal failure in patients with suspected rhabdomyolysis: a systematic review.

Background: Urine myoglobin continues to be used as a marker of rhabdomyolysis, particularly to assess risk of developing acute renal failure and evaluate treatment success. We sought to determine the predictive validity of urine myoglobin (uMb) for acute renal failure (ARF) in patients with suspected rhabdomyolysis.

Methods: We performed a broad systemic review of the literature from January 1980 to December 2006 using the search terms myoglobin$ AND (renal OR ARF OR kidney).

Clinical implication of the difference between transcutaneous bilirubinometry and total serum bilirubin for the classification of newborns at risk of hyperbilirubinemia.

Objectives: 1) To determine the relationship between transcutaneous bilirubin measurements (TcB), performed using BiliCheck or Minolta Air-Shields JM-103, and total serum bilirubin levels (TSB) and 2) to evaluate the predictive accuracy of TcB measurements for risk using the nomogram recommended by the Canadian Pediatric Society (CPS).

Methods: A total of 154 healthy term neonates from the newborn nursery at McMaster Children's Hospital meeting the inclusion criteria were enrolled. TcB measurements were performed within 30 min of obtaining the TSB measurement.

Modification of tryptophan and methionine residues is implicated in the oxidative inactivation of surfactant protein B.

Exposing BLES (bovine lipid extract surfactant), a clinical surfactant, to reactive oxygen species (ROS) alters surfactant protein B (SP-B), as indicated by Coomassie Blue staining, silver staining, and Western analysis. Hypochlorous acid (HOCl) treatment leads to elevated maximum surface tension (gammamax) and a deterioration in minimum gamma (gammamin) during surface area cycling. Fenton reaction resulted in immediate increases in gammamin and gammamax.

Neurobiological effects of intraventricular propionic acid in rats: possible role of short chain fatty acids on the pathogenesis and characteristics of autism spectrum disorders.

Clinical observations suggest that certain gut and dietary factors may transiently worsen symptoms in autism spectrum disorders (ASD), epilepsy and some inheritable metabolic disorders. Propionic acid (PPA) is a short chain fatty acid and an important intermediate of cellular metabolism. PPA is also a by-product of a subpopulation of human gut enterobacteria and is a common food preservative.