RESUMO
OBJECTIVE: To assess the feasibility of T-cell receptor excision circles (TRECs) quantification for neonatal mass screening of severe combined immunodeficiency (SCID). STUDY DESIGN: Real-time PCR based quantification of TRECs for 471 healthy control patients and 18 patients with SCID with various genetic abnormalities (IL2RG, JAK3, ADA, LIG4, RAG1) were performed, including patients with maternal T-cell engraftment (n = 4) and leaky T cells (n = 3). RESULTS: TRECs were detectable in all normal neonatal Guthrie cards (n = 326) at the levels of 10(4) to 10(5) copies/microg DNA. In contrast, TRECs were extremely low in all neonatal Guthrie cards (n = 15) and peripheral blood (n = 14) from patients with SCID, including those with maternal T-cell engraftment or leaky T cells with hypomorphic RAG1 mutations or LIG4 deficiency. There were no false-positive or negative results in this study. CONCLUSION: TRECs quantification can be used as a neonatal mass screening for patients with SCID.
Assuntos
Reparo do DNA/genética , Triagem Neonatal/métodos , Receptores de Antígenos de Linfócitos T/genética , Imunodeficiência Combinada Severa/diagnóstico , Imunodeficiência Combinada Severa/genética , Adolescente , Adulto , Criança , Pré-Escolar , Estudos de Viabilidade , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ribonuclease P/sangue , Imunodeficiência Combinada Severa/sangue , Adulto JovemRESUMO
Disseminated necrotizing leukoencephalopathy (DNL) is a potentially fatal complication of treatment involving intrathecal administration of chemotherapeutic agents such as methotrexate (MTX) alone or in combination with cranial radiotherapy (RT). We describe a case of acute lymphoblastic leukemia (ALL) treated with high-dose intravenous and intrathecal methotrexate combined with craniospinal RT resulting in DNL. Typical MR imaging features of progressive deep white matter lesions showing a characteristic pattern of enhancement after contrast was seen in this case. Deep white matter lesions with ring-like enhancement and calcifications were seen on CT; it showed a mass effect at one stage, which is not typical for DNL. Long-term clinical and imaging follow-up were helpful for the diagnosis in this case.