Validation and development of an immunonephelometric assay for the determination of alpha-1 antitrypsin levels in dried blood spots from patients with COPD

OBJECTIVE: To validate and develop an immunonephelometric assay for the determination of alpha-1 antitrypsin (AAT) levels in dried blood spots from COPD patients in Brazil. METHODS: We determined AAT levels in serum samples and dried blood spots from 192 COPD patients. For the preparation of dried blood spots, a disk (diameter, 6 mm) was placed into a tube, eluted with 200 µL of PBS, and stored overnight at 4ºC. All of the samples were analyzed by immunonephelometry in duplicate. We used the bootstrap resampling method in order to determine a cut-off point for AAT levels in dried blood spots. RESULTS: The correlation coefficient between the AAT levels in serum samples and those in dried blood spots was r = 0.45. For dried blood spots, the cut-off value was 2.02 mg/dL (97% CI: 1.45-2.64 mg/dL), with a sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 95.7%, 27.2%, and 100%, respectively. CONCLUSIONS: This method for the determination of AAT levels in dried blood spots appears to be a reliable screening tool for patients with AAT deficiency.

Download Full-text

Application of Dried Blood Spots and Serum Samples for the Determination of Vitamin D Metabolites in the Group of Healthy Women and with Hashimoto’s Thyroiditis

Chromatographia ◽

10.1007/s10337-021-04047-6 ◽

2021 ◽

Author(s):

R. Rola ◽

E. Trusewicz ◽

T. Bieńkowski ◽

S. Studzińska

Keyword(s):

Vitamin D ◽

Hashimoto’S Thyroiditis ◽

Good Alternative ◽

Dried Blood Spots ◽

Hashimoto's Thyroiditis ◽

Vitamin D Metabolites ◽

Serum Samples ◽

Blood Spots ◽

Healthy Women

Abstract Purpose The relationship between Hashimoto's thyroiditis and vitamin D concentration was already presented in many studies. The aim of this study was to analyze the differences in the concentration of vitamin D metabolites between healthy women and women with Hashimoto's thyroiditis (HT). Methods The quantitative analysis of five vitamin D metabolites was carried out using liquid chromatography coupled with tandem mass spectrometry. The analyzed materials were serum and dried blood spots (DBS). The results obtained for the two materials were also compared. Results No statistically significant differences were found in the mean concentration of the 25(OH)D3, 25(OH)D2, 24,25(OH)2D3, 1,25(OH)2D3 metabolites between the test and the control groups. However, a strong correlation was found between the 25(OH)D3 and 24,25(OH)2D3 metabolites. Conclusion The study showed that healthy women and women with Hashimoto's disease had similar concentration of vitamin D metabolites. Research also proved that DBS is a good alternative to serum. The differences in 25(OH)D concentration were not statistically significant (17.0 and 15.5 ng mL−1 for serum and DBS, respectively). DBS can be successfully used in research on a large group of people, since the process of material collection, as well as sample preparation, is fast and simple. It is also easy to transport and store, and requires small volume of blood.

Download Full-text

Determination of Chloroquine in Dried Blood Spots on Filter Paper

Therapeutic Drug Monitoring ◽

10.1097/00007691-198606000-00015 ◽

1986 ◽

Vol 8 (2) ◽

pp. 211-213 ◽

Cited By ~ 6

Author(s):

Y. Bergqvist ◽

Ö. Ericsson ◽

M. Rais

Keyword(s):

Filter Paper ◽

Dried Blood Spots ◽

Blood Spots

Download Full-text

A specific LC/ESI-MS/MS method for determination of 25-hydroxyvitamin D3 in neonatal dried blood spots containing a potential interfering metabolite, 3-epi-25-hydroxyvitamin D3

Journal of Separation Science ◽

10.1002/jssc.201000911 ◽

2011 ◽

Vol 34 (7) ◽

pp. 725-732 ◽

Cited By ~ 57

Author(s):

Tatsuya Higashi ◽

Masahiro Suzuki ◽

Junji Hanai ◽

Shinsuke Inagaki ◽

Jun Zhe Min ◽

...

Keyword(s):

Dried Blood Spots ◽

Esi Ms ◽

Blood Spots

Download Full-text

The validation of a fluoroimmunoassay for the determination of theophylline concentration in dried blood spots suitable for domiciliary therapeutic drug monitoring

Clinica Chimica Acta ◽

10.1016/0009-8981(84)90291-2 ◽

1984 ◽

Vol 136 (2-3) ◽

pp. 187-195 ◽

Cited By ~ 20

Author(s):

Edward J. Coombes ◽

Timothy R. Gamlen ◽

Gifford F. Batstone ◽

Steven T. Holgate

Keyword(s):

Therapeutic Drug Monitoring ◽

Drug Monitoring ◽

Dried Blood Spots ◽

Therapeutic Drug ◽

Theophylline Concentration ◽

Blood Spots

Download Full-text

Determination of Fentanyl Analog Exposure Using Dried Blood Spots with LC–MS-MS

Journal of Analytical Toxicology ◽

10.1093/jat/bky096 ◽

2018 ◽

Vol 43 (4) ◽

pp. 266-276 ◽

Cited By ~ 9

Author(s):

Craig Seymour ◽

Rebecca L Shaner ◽

Melanie C Feyereisen ◽

Rebekah E Wharton ◽

Pearl Kaplan ◽

...

Keyword(s):

Dried Blood Spots ◽

Blood Spots

Download Full-text

Determination of psychosine concentration in dried blood spots from newborns that were identified via newborn screening to be at risk for Krabbe disease

Clinica Chimica Acta ◽

10.1016/j.cca.2013.01.017 ◽

2013 ◽

Vol 419 ◽

pp. 73-76 ◽

Cited By ~ 44

Author(s):

Wei-Lien Chuang ◽

Josh Pacheco ◽

X. Kate Zhang ◽

Monica M. Martin ◽

Chad K. Biski ◽

...

Keyword(s):

At Risk ◽

Newborn Screening ◽

Dried Blood Spots ◽

Krabbe Disease ◽

Blood Spots

Download Full-text

Newborn Screening for Long-Chain 3-Hydroxyacyl-CoA Dehydrogenase and Mitochondrial Trifunctional Protein Deficiencies Using Acylcarnitines Measurement in Dried Blood Spots—A Systematic Review of Test Accuracy

Frontiers in Pediatrics ◽

10.3389/fped.2021.606194 ◽

2021 ◽

Vol 9 ◽

Author(s):

Chris Stinton ◽

Hannah Fraser ◽

Julia Geppert ◽

Rebecca Johnson ◽

Martin Connock ◽

...

Keyword(s):

Mass Spectrometry ◽

Tandem Mass Spectrometry ◽

Dried Blood Spots ◽

Test Accuracy ◽

Tandem Mass ◽

Blood Spots ◽

Hydroxyacyl Coa Dehydrogenase ◽

Sensitivity Specificity ◽

Long Chain

Background: Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) and mitochondrial trifunctional protein (MTP) deficiencies are rare autosomal recessive fatty acid β-oxidation disorders. Their clinical presentations are variable, and premature death is common. They are included in newborn blood spot screening programs in many countries around the world. The current process of screening, through the measurement of acylcarnitines (a metabolic by-product) in dried blood spots with tandem mass spectrometry, is subject to uncertainty regarding test accuracy.Methods: We conducted a systematic review of literature published up to 19th June 2018. We included studies that investigated newborn screening for LCHAD or MTP deficiencies by tandem mass spectrometry of acylcarnitines in dried blood spots. The reference standards were urine organic acids, blood acylcarnitine profiles, enzyme analysis in cultured fibroblasts or lymphocytes, mutation analysis, or at least 10-year follow-up. The outcomes of interest were sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Assessment of titles, abstracts, and full-text papers and quality appraisal were carried out independently by two reviewers. One reviewer extracted study data. This was checked by a second reviewer.Results: Ten studies provided data on test accuracy. LCHAD or MTP deficiencies were identified in 23 babies. No cases of LCHAD/MTP deficiencies were identified in four studies. PPV ranged from 0% (zero true positives and 28 false positives from 276,565 babies screened) to 100% (13 true positives and zero false positives from 2,037,824 babies screened). Sensitivity, specificity, and NPV could not be calculated as there was no systematic follow-up of babies who screened negative.Conclusions: Test accuracy estimates of screening for LCHAD and MTP deficiencies with tandem mass spectrometry measurement of acylcarnitines in dried blood were variable in terms of PPVs. Screening methods (including markers and thresholds) varied between studies, and sensitivity, specificity, and NPVs are unknown.

Download Full-text

Assessment of DNA contamination from dried blood spots and determination of DNA yield and function using archival newborn dried blood spots

Clinica Chimica Acta ◽

10.1016/j.cca.2008.12.028 ◽

2009 ◽

Vol 402 (1-2) ◽

pp. 107-113 ◽

Cited By ~ 10

Author(s):

Suzanne K. Cordovado ◽

Marie C. Earley ◽

Miyono Hendrix ◽

Rena Driscoll-Dunn ◽

Michael Glass ◽

...

Keyword(s):

Dried Blood Spots ◽

Blood Spots ◽

Dna Yield ◽

Dna Contamination ◽

And Function

Download Full-text

A Negative Antinuclear Antibody Does Not Indicate Autoantibody Negativity in Myositis: Role of Anticytoplasmic Antibody as a Screening Test for Antisynthetase Syndrome

The Journal of Rheumatology ◽

10.3899/jrheum.160618 ◽

2016 ◽

Vol 44 (2) ◽

pp. 223-229 ◽

Cited By ~ 25

Author(s):

Rohit Aggarwal ◽

Namrata Dhillon ◽

Noreen Fertig ◽

Diane Koontz ◽

Zengbiao Qi ◽

...

Keyword(s):

Lupus Erythematosus ◽

Predictive Value ◽

Antinuclear Antibody ◽

High Sensitivity ◽

Epithelial Cell Line ◽

Antisynthetase Syndrome ◽

Control Groups ◽

Serum Samples ◽

Cytoplasmic Staining ◽

Sensitivity Specificity

Objective.To evaluate the utility of anticytoplasmic autoantibody (anti-CytAb) in antisynthetase antibody–positive (anti-SynAb+) patients.Methods.Anti-SynAb+ patients were evaluated for antinuclear antibody (ANA) and anti-CytAb [cytoplasmic staining on indirect immunofluorescence (IIF)] positivity. Anti-SynAb+ patients included those possessing anti-Jo1 and other antisynthetase autoantibodies. Control groups included scleroderma, systemic lupus erythematosus, Sjögren syndrome, rheumatoid arthritis, and healthy subjects. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy of anti-CytAb, and ANA were assessed. Anti-CytAb and ANA testing was done by IIF on human epithelial cell line 2, both reported on each serum sample without knowledge of the clinical diagnosis or final anti-SynAb results.Results.Anti-SynAb+ patients (n = 202; Jo1, n = 122; non-Jo1, n = 80) between 1985–2013 with available serum samples were assessed. Anti-CytAb showed high sensitivity (72%), specificity (89%), NPV (95%), and accuracy (86%), but only modest PPV (54%) for anti-SynAb positivity. In contrast, ANA showed only modest sensitivity (50%) and poor specificity (6%), PPV (9%), NPV (41%), and accuracy (12%). Positive anti-CytAb was significantly greater in the anti-SynAb+ patients than ANA positivity (72% vs 50%, p < 0.001), and 81/99 (82%) ANA-negative patients in the anti-SynAb+ cohort had positive anti-CytAb. In contrast, the control groups showed high rates for ANA positivity (93.5%), but very low rates for anti-CytAb positivity (11.5%). Combining anti-CytAb or Jo1 positivity showed high sensitivity (92%) and specificity (89%) for identification of anti-SynAb+ patients.Conclusion.Assessing patients for anti-CytAb serves as an excellent screen for anti-SynAb+ patients using simple IIF. Cytoplasmic staining should be assessed and reported for patients suspected of having antisynthetase syndrome and a negative ANA should not be used to exclude this diagnosis.

Download Full-text