BACKGROUND: Enumeration of T cell receptor excision circles (TREC) was recently adopted as a neonatal screening assay for severe combined immunodeficiency (SCID). Enumeration of kappa-deleting recombination excision circle (KREC) copy numbers can be similarly used for early assessment of B cell lymphopenia. OBJECTIVE: To assess the ability of TREC and KREC counts to identify patients with combined T and B cell immunodeficiency in a pilot study in Israel. METHODS: We studied seven children born in Israel during the years 2010-2011 and later diagnosed with SCID, and an additional patient with pure B cell immunodeficiency. TREC and KREC in peripheral blood upon diagnosis and in their neonatal Guthrie cards were analyzed using real-time quantitative polymerase chain reaction, as were Guthrie cards with dried blood spots from healthy newborns and from normal and SCID-like controls. RESULTS: The first features suggestive of SCID presented at age 3.1 +/- 2.4 months in all patients. Yet, the diagnosis was made 4.1 +/- 2.9 months later. Their TREC were undetectable or significantly low at their clinical diagnosis and in their originally stored Guthrie cards, irrespective of the amount of their circulating T cells. KREC were undetectable in six SCID patients who displayed B cell lymphopenia in addition to T cell lymphopenia. KREC were also undetectable in one patient with pure B cell immunodeficiency. CONCLUSIONS: TREC and KREC quantification are useful screening tests for severe T and B cell immunodeficiency. Implementation of these tests is highly important especially in countries such as Israel where a high frequency of consanguinity is known to exist.
BACKGROUND: Enumeration of T cell receptor excision circles (TREC) was recently adopted as a neonatal screening assay for severe combined immunodeficiency (SCID). Enumeration of kappa-deleting recombination excision circle (KREC) copy numbers can be similarly used for early assessment of B cell lymphopenia. OBJECTIVE: To assess the ability of TREC and KREC counts to identify patients with combined T and B cell immunodeficiency in a pilot study in Israel. METHODS: We studied seven children born in Israel during the years 2010-2011 and later diagnosed with SCID, and an additional patient with pure B cell immunodeficiency. TREC and KREC in peripheral blood upon diagnosis and in their neonatal Guthrie cards were analyzed using real-time quantitative polymerase chain reaction, as were Guthrie cards with dried blood spots from healthy newborns and from normal and SCID-like controls. RESULTS: The first features suggestive of SCID presented at age 3.1 +/- 2.4 months in all patients. Yet, the diagnosis was made 4.1 +/- 2.9 months later. Their TREC were undetectable or significantly low at their clinical diagnosis and in their originally stored Guthrie cards, irrespective of the amount of their circulating T cells. KREC were undetectable in six SCIDpatients who displayed B cell lymphopenia in addition to T cell lymphopenia. KREC were also undetectable in one patient with pure B cell immunodeficiency. CONCLUSIONS: TREC and KREC quantification are useful screening tests for severe T and B cell immunodeficiency. Implementation of these tests is highly important especially in countries such as Israel where a high frequency of consanguinity is known to exist.
Authors: Jet van der Spek; Rolf H H Groenwold; Mirjam van der Burg; Joris M van Montfrans Journal: J Clin Immunol Date: 2015-04-17 Impact factor: 8.317
Authors: Marilia Pyles P Kanegae; Lucila Akune Barreiros; Jusley Lira Sousa; Marco Antônio S Brito; Edgar Borges de Oliveira; Lara Pereira Soares; Juliana Themudo L Mazzucchelli; Débora Quiorato Fernandes; Sonia Marchezi Hadachi; Silvia Maia Holanda; Flavia Alice T M Guimarães; Maura Aparecida P V V Boacnin; Marley Aparecida L Pereira; Joaquina Maria C Bueno; Anete Sevciovic Grumach; Regina Sumiko W Di Gesu; Amélia Miyashiro N Dos Santos; Newton Bellesi; Beatriz T Costa-Carvalho; Antonio Condino-Neto Journal: Rev Paul Pediatr Date: 2017 Jan-Mar