Complete DiGeorge syndrome: persistence of profound immunodeficiency.

OBJECTIVE: DiGeorge syndrome is characterized by developmental defects of the heart, parathyroid glands, and thymus. The objective of this study was to determine whether T-cell function spontaneously improves in patients with DiGeorge syndrome who have profoundly depressed T-cell proliferative responses to mitogens at presentation, regardless of the T-cell count. STUDY DESIGN: We conducted a retrospective chart review of eight patients with DiGeorge syndrome who had no proliferative responses to mitogens on presentation. RESULTS: Despite lack of responsiveness of the patients' peripheral blood lymphocytes to mitogens, T cells were occasionally detected, and the patients' cells often responded to IL-2 and in mixed lymphocyte reactions. Unresponsiveness to mitogens and clinical immunodeficiency persisted without immune-based therapy. One patient is alive and well after immunoreconstitution from thymic transplantation. The others either died early of complications of their disease such as gastroesophageal reflux with aspiration (2 patients) or infection (2 patients) or died after attempts at immunorestorative therapy with IL-2, thymus transplantation, or bone marrow transplantation (3 patients). CONCLUSION: Eight patients with DiGeorge syndrome who were first seen with no mitogen responsiveness did not improve spontaneously. We recommend HLA-identical bone marrow transplantation or thymic transplantation for these patients as soon as the diagnosis is confirmed.

Human severe combined immunodeficiency: genetic, phenotypic, and functional diversity in one hundred eight infants.

OBJECTIVE: To determine the relative frequencies of the different genetic forms of severe combined immunodeficiency (SCID) and whether there are distinctive characteristics of the particular genotypes. STUDY DESIGN: The demographic, genetic, and immunologic features of 108 infants with SCID who were treated consecutively at Duke University Medical Center were analyzed. RESULTS: Eighty-nine subjects were boys and 19 were girls; there were 84 white infants, 16 black infants, and 8 Hispanic infants. Forty-nine had X-linked SCID with mutations of common cytokine receptor gamma chain (gamma c), 16 had adenosine deaminase (ADA) deficiency, 8 had Janus kinase 3 (Jak3) deficiency, 21 had unknown autosomal recessive mutations, 1 had reticular dysgenesis, 1 had cartilage hair hypoplasia, and 12 (all boys) had SCID of undetermined type. Deficiency of ADA caused the most profound lymphopenia; gamma c or Jak3 deficiency resulted in the most B cells and fewest natural killer (NK) cells; NK cells and function were highest in autosomal recessive and unknown types of SCID. CONCLUSIONS: Different SCID genotypes are associated with distinctive lymphocyte characteristics. The presence of NK function in ADA-deficient, autosomal recessive, and unknown type SCIDs, and low NK function in a majority of gamma c and Jak3 SCIDs indicates that some molecular lesions affect T, B, and NK cells (gamma c and Jak3), others primarily T cells (ADA deficiency), and others just T and B cells.