Abstract：
BACKGROUND:Since its beginnings, newborn screening for cystic fibrosis (CF) using an assay for immunoreactive trypsinogen (IRT) has been plagued by a high rate of false-positive results (screen positive, diagnosis negative), despite attempts to reduce this rate by use of altered cutoffs and second-tier DNA testing. IRT exists as 2 isoforms: IRT1 and IRT2, with IRT2 being more closely aligned with pancreatic disease, including CF. Assay standardization between programs is a continuing problem because the IRT assays currently in use variously recognize either 1 or both isoforms. Here we report the development of a multiplexed assay for both forms of IRT simultaneously. METHODS:Using 2 different Luminex bead sets, we developed assays for each IRT isoform separately and then combined them. Using the sum of IRT1 and IRT2 values (IRT1+IRT2), we compared the results with a CF kit currently in use. RESULTS:In a sample set consisting of 16 cases confirmed positive for CF, we established a cutoff at >97 microg/L total IRT. Seven of 8 carriers with 1 CF mutation screen-positive by the standard method were also screen-positive by IRT1+IRT2. Of 32 cases screen-positive by standard IRT, 11 were screen-negative by IRT1+IRT2. None of these 11 cases had CF mutations identified by the screening program. CONCLUSIONS:These data indicate that the multiplex method with specificity for 2 isoforms of IRT has performance comparable to that of a standard IRT method and the advantage of improved standardization by detection of the 2 isoforms.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Lindau-Shepard BA,Pass KAdoi
10.1373/clinchem.2009.132480subject
Has Abstractpub_date
2010-03-01 00:00:00pages
445-50issue
3eissn
0009-9147issn
1530-8561pii
clinchem.2009.132480journal_volume
56pub_type
杂志文章abstract：INTRODUCTION:Commercially available SARS-CoV-2 serological assays based on different viral antigens have been approved for the qualitative determination of anti-SARS-CoV-2 antibodies. However, there are limited published data associating the results from commercial assays with neutralizing antibodies. METHODS:67 speci...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1093/clinchem/hvaa211
更新日期：2020-09-07 00:00:00
abstract：:We report here the evaluation of the Abbott TDx assay with a monoclonal antibody for selectively quantifying cyclosporine (CsA) in whole blood. Over the clinically relevant concentration ranges, results with this assay demonstrated within- and between-run CVs of less than 2.5% and 5%, respectively; sensitivity of 25 m...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-11-01 00:00:00
abstract：:A two-site assay was developed by use of the "dissociation and enhancement lanthanide fluoroimmunoassay" (DELFIA) technique for determination of salmon calcitonin (SCT) in serum after administration to osteoporotic patients. Polyclonal antibodies were produced in rabbits immunized with SCT coupled to ovalbumin. After ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-09-01 00:00:00
abstract：BACKGROUND:SELDI-TOF mass spectrometry (MS) is a high-throughput proteomic approach with potential for identifying novel forms of serum biomarkers of arthritis. METHODS:We used SELDI-TOF MS to analyze serum samples from patients with various forms of inflammatory arthritis. Several protein profiles were collected on d...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2007.099549
更新日期：2008-06-01 00:00:00
abstract：:6-thioguanine (6-TGN) and methyl 6-mercaptopurine nucleotides (Me6-MPNs) are the two major metabolites found in erythrocytes after administration of azathioprine. In an attempt to understand the role of these metabolites in the pharmacologic and toxic activity of thiopurines, we have developed a HPLC method for the si...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-03-01 00:00:00
abstract：:We describe an automated assay of glycohemoglobin performed with the Abbott Vision analyzer. The assay is based on batch affinity-extraction with 3-aminophenylboronic acid-derivatized agarose beads. Reagents are packaged in a disposable test pack. Whole-blood specimens are hemolyzed with saponin within a glass capilla...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-12-01 00:00:00
abstract：BACKGROUND:PCR-based detection of minimal residual disease (MRD) in neuroblastoma (NB) patients can be used for initial staging and monitoring therapy response in bone marrow (BM) and peripheral blood (PB). PHOX2B has been identified as a sensitive and specific MRD marker; however, its expression varies between tumors....
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2008.117945
更新日期：2009-07-01 00:00:00
abstract：:The manual Reference Method of the Centers for Disease Control for serum iron (CDC/RM/Fe) and a semiautomated adaptation of it were used to evaluate two working methods: one, a detergent solubilization procedure for the Roche Cobas-Bio analyzer, the other, the Kodak Ektachem 700 procedure, based on dry-film technology...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-10-01 00:00:00
abstract：BACKGROUND:The accurate and precise measurement of urinary albumin is critical, since even minor increases are diagnostically sensitive indicators of renal disease, cardiovascular events, and risk for death. To gain insights into potential measurement biases, we systematically compared urine albumin measurements perfor...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2008.107508
更新日期：2008-09-01 00:00:00
abstract：:This one-dimensional thin-layer chromatographic method is used for assay of phospholipids in the gastric aspirate of newborns. The solvent mixture (chloroform/hexane/methanol/glacial acetic acid/water, 12/7/4/3/0.3 by vol) completely resolves lecithin, sphingomyelin, phosphatidylinositol, phosphatidylserine, phosphati...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-04-01 00:00:00
abstract：:Urinary acidic and alcoholic catecholamine metabolites were isolated separately from 24-h urines by simple extraction procedures. After derivatization, extracts were analyzed by means of simultaneous gas chromatography on two different stationary phases. The quality of the assay was checked by running "normal" and enr...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-05-01 00:00:00
abstract：:We evaluated a new EMIT II monoclonal amphetamine/methamphetamine assay for screening human urine by comparing it with the EMIT d.a.u. monoclonal amphetamine/methamphetamine assay and a fluorescence polarization assay. The EMIT II assay has a cutoff of 1 mg/L d-methamphetamine. The EMIT II and EMIT d.a.u. assays were ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1993-01-01 00:00:00
abstract：:We examined the changes in sensitivity and specificity that would occur with alterations in the sample-collection schedule and (or) cutoff criterion for the increase in hydrogen concentration in breath after administration of doses of lactose in the dietary range. In a breath-analysis test to classify individuals as l...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-03-01 00:00:00
abstract：BACKGROUND:The goal of this study was to establish a plasma microRNA profile by use of next-generation sequencing that could aid in assessment of patient prognosis in nasopharyngeal carcinoma (NPC). METHODS:Two panels of NPC patients and healthy controls (HCs) were recruited for this study. We used deep sequencing to ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2013.214213
更新日期：2014-05-01 00:00:00
abstract：BACKGROUND:The analysis of bodily fluids using SELDI-TOF MS has been reported to identify signatures of spectral peaks that can be used to differentiate patients with a specific disease from normal or control patients. This report is the 2nd of 2 companion articles describing a validation study of a SELDI-TOF MS approa...
journal_title：Clinical chemistry
pub_type： 杂志文章,多中心研究
doi：10.1373/clinchem.2007.091496
更新日期：2008-01-01 00:00:00
abstract：BACKGROUND:Paraoxonase may mitigate oxidative damage and thus lower risk of macrovascular disease. METHODS:DNA samples from 2252 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study were genotyped for the L55M and Q192R polymorphisms of the PON1 (paraoxonase 1) gene, and paraoxonase acti...
journal_title：Clinical chemistry
pub_type： 杂志文章,多中心研究
doi：10.1373/clinchem.2007.099044
更新日期：2008-04-01 00:00:00
abstract：BACKGROUND:Simple, reproducible assays are needed for the quantification of sphingolipids, ceramide (Cer), and sphingoid bases. We developed an HPLC method for simultaneous quantification of total plasma concentrations of Cer, glucosylceramide (GlcCer), and ceramide trihexoside (CTH). METHODS:After addition of sphinga...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2006.079012
更新日期：2007-04-01 00:00:00
abstract：:We evaluated a new analyzer that measures lactate in undiluted whole blood by direct (or undiluted) amperometry [Nova Stat Profile 7 Analyzer (SP7); Nova Biomedical, Waltham, MA] by comparing it with two other analyzers, one for measuring lactate in whole blood by indirect (or diluted) amperometry [Model 2300; Yellow ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-12-01 00:00:00
abstract：BACKGROUND:Bilirubin has antioxidative and cytoprotective properties. Low plasma concentrations of bilirubin are reportedly associated with the development of coronary and cerebrovascular disease, and bilirubin concentrations are strongly correlated with the enzyme activity of the hepatic uridine diphosphate glucuronos...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：10.1373/clinchem.2007.102046
更新日期：2008-05-01 00:00:00
abstract：:We report the results of a laboratory and clinical evaluation of a commercial kit procedure (Immuno Nuclear Corp.) for measuring the mid-region of the parathyrin molecule. The estimated dose at 50% binding averaged 130 pmol/L, and the minimum detectable concentration was 14 pmol/L. The within-assay CV was less than or...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-11-01 00:00:00
abstract：BACKGROUND:Clinical diagnoses were correlated with results of a Co(II)-albumin binding assay in 167 patients treated at an emergency department of a health maintenance organization. METHODS:Patients were evaluated as being nonischemic or potentially ischemic through standard coronary disease indicators [creatine kinas...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：10.1373/49.4.581
更新日期：2003-04-01 00:00:00
abstract：BACKGROUND:Commercial immunoassays for testosterone (Te) may give inaccurate results for samples from women and children, leading to misdiagnosis and inappropriate treatment. We developed a sensitive and specific tandem mass spectrometric assay for measurement of Te at the concentrations encountered in women and childr...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2005.052167
更新日期：2006-01-01 00:00:00
abstract：:We combined the amplification refractory mutation system (ARMS) and fluorescence polarization (FP) to give a homogeneous genomic DNA genotype analysis method. Oligonucleotide probes labeled with the fluorescein dyes fluorescein isothiocyanate and 5-([4,6-dichlorotriazin-2-yl]amino)fluorescein and the rhodamine dye 6-c...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1997-08-01 00:00:00
abstract：BACKGROUND:Plasma creatinine concentration and calculated creatinine clearance are of limited value as glomerular filtration rate (GFR) markers in patients with decompensated liver cirrhosis. We assessed plasma cystatin C as an indicator of GFR in such patients. METHODS:We studied 36 patients with decompensated liver ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2002-06-01 00:00:00
abstract：:We measured total serum bile acids on a fluorescence-light-scattering micro centrifugal analyzer by the direct enzymatic method with 3 alpha-hydroxysteroid dehydrogenase (EC 1.1.1.50) and with resazurin as a fluorogenic electron acceptor. We found that serum protein has an inhibitory effect on the measurement of bile ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-01-01 00:00:00
abstract：:A one-stage semiautomated method for estimating total phospholipids in plasma is reported. The phospholipids are extracted into aqueous ethanol, combined with a Lewis acid, and the change in pH is monitored colorimetrically. The method, compared with the acid digestion method of Gomori [J. Lab. Clin. Med. 27, 955 (194...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-09-01 00:00:00
abstract：:We describe a chromatographic system involving a high-performance chemically-bonded reverse-phase column and fluorescence detection for measurement of indoles in urine. We controlled retention and selectivity by optimizing the methanol content and pH of the mobile phase. Six reference indoles were separated in less th...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-02-01 00:00:00
abstract：:This highly sensitive method for determination of beta 2-microglobulin (beta 2-m) in human urine or serum is based on direct agglutination by beta 2-m of latex particles on which an antibody against beta 2-m is adsorbed. The agglutination is quantified by counting the remaining unagglutinated particles, or by turbidim...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-06-01 00:00:00
abstract：BACKGROUND:The susceptibility of plasma lipids to oxidation is thought to be a factor contributing to atherogenic risk. Various groups have studied the in vitro oxidizability of isolated LDL and examined the effects of conventional antioxidants. The drawbacks associated with the isolation of LDL for evaluation of in vi...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2005.051078
更新日期：2005-11-01 00:00:00
abstract：:We present data on a filter-paper collection and assay method for measurement of glycated hemoglobin (gHb). Onto filter paper dipped into a solution of glucose oxidase (EC 1.1.3.4) and allowed to dry, approximately 20 microL of capillary blood was spotted. For analysis, we eluted the dried blood spot from the paper by...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-05-01 00:00:00
