Thyroid screening of neonates without use of radioactivity: evaluation of time-resolved fluoroimmunoassay of thyrotropin.

1986 ◽  
Vol 32 (6) ◽  
pp. 1013-1016 ◽  
Author(s):  
T E Torresani ◽  
R Scherz
Keyword(s):  
Early Diagnosis ◽  
Congenital Hypothyroidism ◽  
False Positive ◽  
Dried Blood Spots ◽  
Screening Assay ◽  
Time Resolved ◽  
Blood Samples ◽  
Thyroid Screening ◽  
Positive Results

Abstract We evaluated the usefulness, in routine newborn screening for congenital hypothyroidism, of a time-resolved fluoroimmunoassay kit (DELFIA Neonatal TSH) for the determination of thyrotropin (TSH) in dried blood spots. A total of 11 531 dried blood samples from newborns were tested in parallel in each of two Swiss screening laboratories, by RIA and DELFIA. Six cases of confirmed congenital hypothyroidism were detected during the study period. The rate of false-positive results, after single TSH determination in the DELFIA assay, was 0.16%. Correlation of RIA and DELFIA results for TSH was very good in both laboratories (0.959 and 0.97, respectively). The new method fulfills the criteria for precision and sensitivity of a screening assay. Screening results are usually available the day after the sample arrives in the laboratory, thus favoring early diagnosis and allowing treatment to begin by the seventh or eighth postnatal day.

Thyroid Screening for Early Discharged Infants

PEDIATRICS ◽  
1996 ◽  
Vol 98 (1) ◽  
pp. 41-44
Author(s):  
Judy G. Saslow ◽  
Ernest M. Post ◽  
Carol A. Southard
Keyword(s):  
New Jersey ◽  
Congenital Hypothyroidism ◽  
False Positive ◽  
False Negative ◽  
Negative Results ◽  
Thyroid Screening ◽  
False Negative Results ◽  
Positive Results

Objective. As neonatal discharge before 24 hours of life becomes commonplace, the rejection of congenital hypothyroidism (CH) screening specimens obtained too early has created the need for numerous additional tests. We sought to determine whether the specimens obtained before 24 hours could be used safely. Methods. During a 31-day period we measured thyrotropin in all thyroid-screening specimens that had been obtained before 24 hours. We also examined the early specimens from every infant diagnosed in New Jersey with CH during 1993 or 1994. Results. Among the 663 specimens, those obtained at or before 12 hours and those from infants with birth weights less than 2500 g had too many low thyroxine results to be useful. Among the 515 specimens obtained at more than 12 to 24 hours from newborns weighing 2500 g or more, 37 (7%) had low thyroxine levels and 12 (2.3%) had thyrotropin levels of 20 µIU/mL (mU/L) or higher. Four hundred seventy-one of the 515 infants had subsequent specimens obtained at more than 24 hours, and none of the results were abnormal. There was no child weighing more than or equal to 2500 g who was diagnosed with CH in 1993 and 1994 whose specimen obtained at 24 hours or less was normal. Conclusions. Accepting specimens obtained at more than 12 to 24 hours from infants weighing 2500 g or more would have resulted in more than the usual number of false-positive results but no false-negative results. This would have decreased the requests for additional specimens by more than 90%.

Interference by Tin in AOAC Dry-Ash Voltammetric Method for Determination of Lead and Cadmium in Canned Foods

1988 ◽  
Vol 71 (4) ◽  
pp. 857-859
Author(s):  
Walter Holak ◽  
John J Specchio
Keyword(s):  
Tartaric Acid ◽  
False Positive ◽  
Supporting Electrolyte ◽  
Canned Food ◽  
Voltammetric Method ◽  
Lead And Cadmium ◽  
Anodic Stripping ◽  
Canned Foods ◽  
Positive Results

Abstract When lead and cadmium were determined in samples of canned food by the AOAC anodic stripping voltammetric method, an interference was observed which was believed to be tin(IV). This interference could cause false positive results for lead and cadmium. The electroactivity of tin(IV) was suppressed by increasing the concentration of tartaric acid in the supporting electrolyte from 0.005M to 0.1M after mixing with an equal volume of sample solution.

Immunofluorometry of thyrotropin, from whole-blood spots on filter paper, to screen for congenital hypothyroidism.

1986 ◽  
Vol 32 (10) ◽  
pp. 1854-1856 ◽  
Author(s):  
J Arends ◽  
B Nørgaard-Pedersen
Keyword(s):  
Monoclonal Antibodies ◽  
Congenital Hypothyroidism ◽  
Filter Paper ◽  
Clinical Evidence ◽  
Type System ◽  
Time Resolved ◽  
Sandwich Type ◽  
Blood Specimens ◽  
Positive Results ◽  
Paper Disc

Abstract We have evaluated a time-resolved immunofluorometric assay (IFMA) for determining thyrotropin. This "sandwich"-type system involves two monoclonal antibodies directed against different epitopes. A linear relationship between signal and thyrotropin concentration was observed up to 6000 milli-int. units/L. This procedure takes one day, vs six days with our present RIA technique, and requires only a tenth as much sample. Furthermore, intra- and interassay CVs are lower than with RIA. Assay of 19 paper-disc blood specimens from newborns identified as having congenital hypothyroidism, both by RIA and by clinical evidence, also gave positive results with IFMA. In prospective assay of 3944 specimens by both methods we identified one case of congenital hypothyroidism, which was detected by both techniques. Technical false-positive reactions, identified as such by repeated analyses, were fewer with the IFMA method than with RIA.

Can cadaverous pollution from environmental lead misguide to false positive results in the histochemical determination of gunshot residues? Study on cadaveric skin samples

2017 ◽  
Vol 277 ◽  
pp. 16-20 ◽  
Author(s):  
Michele Boracchi ◽  
Salvatore Andreola ◽  
Federica Collini ◽  
Guendalina Gentile ◽  
Francesca Maciocco ◽  
...  
Keyword(s):  
False Positive ◽  
Gunshot Residues ◽  
Environmental Lead ◽  
Positive Results ◽  
Skin Samples

scholarly journals NeoSeq: a new method of genomic sequencing for newborn screening

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Huaiyan Wang ◽  
Yuqi Yang ◽  
Lingna Zhou ◽  
Yu Wang ◽  
Wei Long ◽  
...  
Keyword(s):  
Newborn Screening ◽  
False Positive ◽  
Disease Risk ◽  
Amplicon Sequencing ◽  
Dried Blood Spots ◽  
Inborn Errors ◽  
Screening Cost ◽  
Diagnostic Time ◽  
Significant Difference ◽  
Positive Results

Abstract Objective To explore the clinical application of NeoSeq in newborn screening. Methods Based on the results obtained from traditional newborn screening (NBS) with tandem mass spectrometry (TMS), three cohorts were recruited into the present study: 36 true positive cases (TPC), 60 false-positive cases (FPC), and 100 negative cases. The dried blood spots of the infants were analyzed with NeoSeq, which is based on multiplex PCR amplicon sequencing. Results Overall, the sensitivity of NeoSeq was 55.6% (20/36) in the detection of TPC. NeoSeq detected disease-related genes in 20 of 36 TPC infants, while it could not identify these genes in eight children. Five cases (3.1%) with disease risk were additionally found in the FPC and NC cohorts. There was a significant difference in the diagnostic time between the two methods—10 days for NeoSeq vs. 43 days for traditional NBS. Conclusions NeoSeq is an economic genomic screening test for newborn screening. It can detect most inborn errors of metabolism, reduce the rate of false positive results, shorten the porting cycles, and reduce the screening cost. However, it is still necessary to further optimize the panel design and add more clinically relevant genomic variants to increase its sensitivity.

scholarly journals Detection and Species Determination of Malaria Parasites by PCR: Comparison with Microscopy and with ParaSight-F and ICT Malaria Pf Tests in a Clinical Environment

1999 ◽  
Vol 37 (5) ◽  
pp. 1269-1273 ◽  
Author(s):  
Jill M. Tham ◽  
Szu Hee Lee ◽  
Theresa M. C. Tan ◽  
Robert C. Y. Ting ◽  
Ursula A. K. Kara
Keyword(s):  
False Positive ◽  
False Negative ◽  
Dried Blood Spots ◽  
Species Differentiation ◽  
Clinical Environment ◽  
Species Determination ◽  
Easy Method ◽  
Two Samples ◽  
Positive Results ◽  
Pcr Test

A rapid procedure for the diagnosis of malaria infections directly from dried blood spots by PCR amplification was evaluated with samples from 52 patients. Plasmodium infections were identified with a genus-specific primer set, and species differentiation betweenPlasmodium falciparum and Plasmodium vivax was analyzed by multiplex PCR. The PCR test with any of the three primer sets was able to detect as few as four parasites per microliter by gel electrophoresis or by nonisotopic paper hybridization chromatography. The diagnoses obtained by PCR correlated closely with those obtained by Giemsa staining except for two samples observed to have mixed P. falciparum-P. vivax infections. These were initially missed by microscopic analysis. In comparison with antigen-capture assays forP. falciparum, the PCR assays were able to detect three infections that were missed by the ParaSight-F test. The PCR test was negative for nine ParaSight-F-positive samples and one ICT Malaria Pf-positive sample, and these were confirmed to be false-positive results. The PCR thus gave no false-negative or false-positive results. Patients undergoing antimalarial therapy were also monitored by the PCR assay. Four of seven patients who were PCR positive forP. vivax at the time of discharge were later readmitted to the hospital with a recurrence of P. vivax infection. We would like to propose that PCR is a sensitive and easy method that can serve as a useful addition to microscopy for the diagnosis and the clinical monitoring of treatment of malaria.

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