Performance of succinylacetone assays and their associated proficiency testing outcomes

Adam, Barbara W.; Hall, Elizabeth M.; Meredith, Nancy K.; Lim, Timothy H.; Haynes, Christopher A.; Jesús, Víctor R. De; Hannon, W. Harry

doi:10.1016/j.clinbiochem.2012.08.007

Cited by 8 publications

(8 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Precision (the ability to consistently reproduce a result when sub-samples are taken from the same specimen) results were presented in seven studies with inter-assay coefficients of variation (CV) at different SUAC concentrations of 10.0-12.2% [ 14 ], 7.1-8.5% [ 21 ], 3.50-4.49% [ 22 ], 5.8-13% [ 19 ], 15.8-16.7% [ 24 ], 17.29-19.00% [ 23 ] and 30% in a pooled sample assay [ 20 ]. Taken together, the analytical performance of the screening tests used in the included studies was in agreement with previously reported proficiency testing outcomes [ 26 , 28 , 29 ], showing large between-laboratory differences in SUAC recoveries (mostly incomplete recoveries) depending on the method used and reproducible within-laboratory recoveries. There is need to harmonise quantitative results among laboratories.…”

Section: Discussionsupporting

confidence: 88%

“…For example, the SUAC cut-offs used in the screening test to identify possible cases of TYR1 ranged from 1.29 μmol/l [ 23 ] to 10 μmol/l [ 19 ]. Proficiency testing results for SUAC in dried blood spots have shown large differences among screening laboratories in SUAC recovery reflecting analytic biases, which might explain the wide variation in cut-off values of the studies in our review [ 26 ]. Differences in recovery could be explained by the method used (kit TMS vs. non-kit TMS; butyl ester derivatisation vs. non-derivatisation), DBS extraction strategy (freshly punched DBS, residual DBS or co-extraction of AA, AC, and SUAC, respectively), internal standard used ( 13 C-SUAC, 5,7-dioxooctanoic acid, or TMS kit internal standard), or the calibration strategy used (DBS calibrators, TMS internal standard/other liquid standard or kit internal standard only, respectively).…”

Section: Discussionmentioning

confidence: 99%

“…Differences in recovery could be explained by the method used (kit TMS vs. non-kit TMS; butyl ester derivatisation vs. non-derivatisation), DBS extraction strategy (freshly punched DBS, residual DBS or co-extraction of AA, AC, and SUAC, respectively), internal standard used ( 13 C-SUAC, 5,7-dioxooctanoic acid, or TMS kit internal standard), or the calibration strategy used (DBS calibrators, TMS internal standard/other liquid standard or kit internal standard only, respectively). Laboratories that measure low quantitative SUAC results usually used lower cut-off values to avoid misclassifications [ 26 ]. This highlights an important issue in how screening tests are evaluated.…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Newborn screening for Tyrosinemia type 1 using succinylacetone – a systematic review of test accuracy

Stinton

Geppert

Freeman

et al. 2017

Orphanet J Rare Dis

View full text Add to dashboard Cite

BackgroundTyrosinemia type 1 is an autosomal recessive disorder of amino acid metabolism. Without treatment, death in childhood is common. Treatment with nitisinone and dietary restrictions are associated with improved outcomes; some studies suggest better outcomes when treatment begins at an asymptomatic stage. Newborn screening allows for earlier identification, but there is uncertainty regarding the test accuracy of the current method: succinylacetone measurement in dried blood spots using tandem mass spectrometry.MethodsWe conducted a systematic review of literature published up to January 2016. Two reviewers independently assessed titles, abstracts, full texts, and conducted quality appraisals. A single reviewer extracted data, which was checked by a second reviewer.ResultsTen studies provided test accuracy data: five studies reporting screening experiences and five case–control studies. Sensitivity (29 cases in total) and specificity (34,403 controls in total) were 100% in the case–control studies, but could not be calculated in the studies reporting screening experiences due to a lack of follow-up of screen-negative babies. Positive predictive values in the screening experience studies ranged from 66.7% (2 true positive cases, 1 false positive case from ~500,000 people screened) to 100% (8 true positive cases from 856,671 people screened); negative predictive values could not be calculated. Positive and negative predictive values cannot be calculated from case–control studies.ConclusionsScreening for Tyrosinemia type 1 using tandem mass spectrometry measurement of succinylacetone from dried blood spots appears to be promising. Confirmation of test accuracy data should be obtained from studies that include a two-year follow-up of individuals who screen negative.Electronic supplementary materialThe online version of this article (doi:10.1186/s13023-017-0599-z) contains supplementary material, which is available to authorized users.

show abstract

Section: Discussionsupporting

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Newborn screening for Tyrosinemia type 1 using succinylacetone – a systematic review of test accuracy

Stinton

Geppert

Freeman

et al. 2017

Orphanet J Rare Dis

View full text Add to dashboard Cite

show abstract

“…SUAC was added to the program in 2008 in response to an increasing number of state public laboratories adopting SUAC testing in their panels [25, 26]. The PT program distributes quarterly panels of blind-coded DBS specimens to participating laboratories and provides an independent external assessment of each laboratory’s performance.…”

Section: Methodsmentioning

confidence: 99%

Succinylacetone as primary marker to detect tyrosinemia type I in newborns and its measurement by newborn screening programs

Jesús

Adam

Mandel

et al. 2014

Molecular Genetics and Metabolism

View full text Add to dashboard Cite

Tyrosinemia type I (TYR I) is caused by autosomal recessive fumarylacetoacetate hydrolase deficiency and is characterized by development of severe liver disease in infancy and neurologic crises. If left untreated, most patients die of liver failure in the first years of life. Intervention with medication is effective when initiated during the first month of life. This improvement in the treatment of TYR I patients influenced the decision to include TYR I in the US Secretary of the Department of Health and Human Services’ (HHS) Recommended Uniform Screening Panel. However, while tyrosine is routinely measured in newborn screening (NBS) by tandem mass spectrometry (MS/MS), elevated tyrosine levels are not specific to TYR I. To improve the specificity of NBS for TYR I, several assays were developed to measure succinylacetone (SUAC) in dried blood spots (DBS). SUAC is a pathognomonic marker of TYR I, and its detection by NBS MS/MS is possible. This review of the current status of NBS for TYR I in the US is the result of discussions at the HHS Secretary’s (Discretionary) Advisory Committee on Heritable Disorders in Newborns and Children about the inconsistent implementation of effective NBS for TYR I in the US. We sought to understand the different TYR I screening practices in US NBS programs. Results indicate that 50 out of 51 NBS programs in the US screen for TYR I, and a successful SUAC performance evaluation scheme is available from the Centers for Disease Control and Prevention. Programmatic and methodological barriers were identified that prevent widespread adoption of SUAC measurements in NBS laboratories. However, since SUAC detection is currently the best approach to NBS for TYR I, a further delay of the addition of SUAC measurement into NBS procedures is discouraged. SUAC measurement should improve both the false positive and false negative rate in NBS for TYR I thereby yielding the desired benefits for affected patients at no expense to the overall population served.

show abstract

“…It is a qualitative test with less than 4 hours procedure. In our study the sensitivity of the test was higher than 95%, which is completely acceptable for being a screening test ( 13 ).…”

Section: Discussionmentioning

confidence: 47%

A Rapid Screening Test on Dried Blood for the Neonatal Diagnosis of Tyrosinemia Type I

et al. 2016

View full text Add to dashboard Cite

Background:Tyrosinemia is an inherited metabolic disorder characterized by elevated levels of tyrosine and its metabolites in plasma. Without treatment, the disease will progress to hepatic and renal failure, so that without liver transplantation will cause death in less than 10 years of age. So, early diagnosis and treatment can be life saving and crucial. It means that with early treatment starting in the neonatal period, the patient can have normal life with very few restrictions in diets containing tyrosine and phenylalanine.Objectives:In this study we wanted to evaluate an easy to perform, rapid and sensitive qualitative test with low cost, as a part of neonatal screening tests to help early diagnosis and treatment of hereditary tyrosinemia.Patients and Methods:In this cross sectional study, during the study period (2013 - 2014), 100 patients were selected. Fifty three (53) of these patients had proven tyrosinemia and the other 47 cases biliary atresia, paucity of intrahepatic bile ducts, cytomegalovirus (CMV) hepatitis, galactosemia and storage diseases. Results:There were 2 false negative and 14 false positive cases of hereditary tyrosinemia (HT-1) in the test. Six cases of biliary atresia, 7 cases of paucity of intrahepatic bile ducts and one patient with cytomegalovirus (CMV) hepatitis were falsely positive with the test. Sensitivity of the test was 96.23%, specificity 71.43%, positive predictive value (PPV) 78.46%, and negative predictive value (NPV) 94.59%.Conclusions:This rapid qualitative test on dried blood sample is an easy, cheap, and feasible method for the screening of hereditary tyrosinemia in neonatal period.

show abstract

Performance of succinylacetone assays and their associated proficiency testing outcomes

Abstract: Background-Succinylacetone (SUAC) is the primary metabolic marker for hepatorenal tyrosinemia.

Cited by 8 publications

References 9 publications

Newborn screening for Tyrosinemia type 1 using succinylacetone – a systematic review of test accuracy

Newborn screening for Tyrosinemia type 1 using succinylacetone – a systematic review of test accuracy

Succinylacetone as primary marker to detect tyrosinemia type I in newborns and its measurement by newborn screening programs

A Rapid Screening Test on Dried Blood for the Neonatal Diagnosis of Tyrosinemia Type I

Contact Info

Product

Resources

About