title: Positive Family History, Infection, Low Absolute Lymphocyte Count (ALC), and Absent Thymic Shadow: Diagnostic Clues for All Molecular Forms of Severe Combined Immunodeficiency (SCID).
abstract: BACKGROUND
  Severe combined immunodeficiency (SCID) is a syndrome uniformly fatal during infancy unless recognized and treated successfully by bone marrow transplantation or gene therapy. Because infants with SCID have no abnormal physical appearance, diagnosis is usually delayed unless newborn screening is performed.
  
  
  OBJECTIVE
  In this study, we sought to evaluate the presenting features of all 172 patients with SCID transplanted at this institution over the past 31 years.
  
  
  METHODS
  We reviewed original charts from 172 consecutive patients with classic SCID who received either T-cell-depleted HLA-haploidentical (N = 154) or HLA-identical (N = 18) nonablative related marrow transplants at Duke University Medical Center from 1982 to 2013.
  
  
  RESULTS
  The mean age at presentation was 4.87 months. When there was a family history of early infant death or known SCID (37%), the mean presentation age was much earlier, 2.0 months compared with 6.6 months. Failure to thrive was common, with 84 patients (50%) having a weight less than the 5th percentile. The leading infections included oral moniliasis (43%), viral infections (35.5%), and Pneumocystis jiroveci (26%) pneumonia. The group mean absolute lymphocyte count (ALC) was 1454/cmm; 88% of the infants had an ALC less than 3000/cmm. An absent thymic shadow was seen in 92% of infants with electronic radiographic data available. An absence of T-cell function was found in all patients.
  
  
  CONCLUSIONS
  Infants with SCID appear normal at birth but later present with failure to thrive and/or recurrent fungal, viral, and bacterial infections. Low ALCs and an absent thymic shadow on chest x-ray are key diagnostic clues. The absence of T-cell function confirms the diagnosis.
authors.affiliation: Departments of Pediatrics and Immunology, Duke University Medical Center, Durham, NC.
authors.forename: Laurie M
authors.initials: LM
authors.lastname: McWilliams
authors.affiliation: Departments of Pediatrics and Immunology, Duke University Medical Center, Durham, NC.
authors.forename: Mary
authors.initials: M
authors.lastname: Dell Railey
authors.affiliation: Departments of Pediatrics and Immunology, Duke University Medical Center, Durham, NC. Electronic address: buckL003@mc.duke.edu.
authors.forename: Rebecca H
authors.initials: RH
authors.lastname: Buckley
mesh_terms: D016026:Bone Marrow Transplantation; D002180:Candidiasis, Oral / Q000175:diagnosis / Q000276:immunology; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000097:blood; D007223:Infant; D007231:Infant, Newborn; D018655:Lymphocyte Count; D008297:Male; D011020:Pneumonia, Pneumocystis / Q000175:diagnosis / Q000276:immunology; D011859:Radiography; D016511:Severe Combined Immunodeficiency / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology / Q000628:therapy; D013601:T-Lymphocytes / Q000276:immunology; D013950:Thymus Gland / Q000000981:diagnostic imaging; D014777:Virus Diseases / Q000175:diagnosis / Q000276:immunology
chemical_list: D007136:Immunoglobulins
keywords: Absent thymic shadow; Failure to thrive infections; Lymphopenia; Severe combined immunodeficiency
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