Prospective neonatal screening for severe T- and B-lymphocyte deficiencies in Seville.
Pediatr Allergy Immunol
; 27(1): 70-7, 2016 Feb.
Article
em En
| MEDLINE
| ID: mdl-26498110
ABSTRACT
BACKGROUND:
Early diagnosis of primary immunodeficiency such as severe combined immunodeficiency (SCID) and X-linked agammaglobulinemia (XLA) improves outcome of affected children. T-cell-receptor-excision circles (TRECs) and kappa-deleting-recombination-excision circles (KRECs) determination from dried blood spots (DBS) identify neonates with severe T- and/or B-lymphopenia. No prospective data exist of the impact of gestational age (GA) and birth weight (BW) on TRECs and KRECs values.METHODS:
TRECs and KRECs determination using triplex RT-PCR (TRECS-KRECS-ß-actin-Assay) from prospectively collected DBS between 02/2014 and 02/2015 in three hospitals in Seville, Spain. Cut-off levels were TRECs < 6/punch, KRECs < 4/punch and -ß-actin>700/punch. Internal (SCID, XLA, ataxia telangiectasia) and external controls (NBS quality assurance program, CDC) were included.RESULTS:
A total of 5160 DBS were tested. Re-punch was needed in 77 samples (1.5%) due to insufficient ß-actin (<700 copies/punch). Pre-term neonates (GA<37 weeks) and neonates with a BW<2500 g showed significantly lower TRECs and KRECs levels (p < 0.001). Due to repeat positive results five neonates were re-called (<0.1%) Fatal chromosomopathy (n = 1; TRECs 1/KRECs 4); extreme pre-maturity (n = 2; TRECs 0/KRECs 0 and TRECs 1/KRECs 20 copies/punch); neonates born to mothers receiving azathioprine during pregnancy (n = 2; TRECs 92/KRECs 1 and TRECs 154/KRECs 3 copies/punch). All internal and external controls were correctly identified.CONCLUSIONS:
TRECS-KRECS-ß-actin-Assay correctly identifies T- and B-cell lymphopenias. Pre-maturity and low BW is associated with lower TREC and KREC levels. Extreme pre-maturity and maternal immune suppressive therapy may be a cause for false positive results of TRECs and KRECs values, respectively. To reduce the rate of insufficient samples, DBS extraction and storage need to be improved.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Linfócitos B
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Linfócitos T
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Triagem Neonatal
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Teste em Amostras de Sangue Seco
/
Reação em Cadeia da Polimerase Multiplex
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Reação em Cadeia da Polimerase em Tempo Real
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Síndromes de Imunodeficiência
Tipo de estudo:
Clinical_trials
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Diagnostic_studies
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Etiology_studies
/
Observational_studies
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Prognostic_studies
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Risk_factors_studies
/
Screening_studies
Limite:
Female
/
Humans
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Male
/
Newborn
País/Região como assunto:
Europa
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article