Immune-deficient bronchiectasis associated with X-linked lymphoproliferative disease

Persistent hypogammaglobulinemia following mononucleosis in boys is highly suggestive of X-linked lymphoproliferative disease--report of three cases

Hypogammaglobulinemia is a common symptom in different immunodeficiencies. It is, however, not usually associated with Epstein-Barr virus (EBV) infections. The X-linked lymphoproliferative disease (XLP) on the other hand shows immunological changes in response to the EBV. Here we report three previously healthy boys, all of which developed persistent hypogammaglobulinemia following severe acute infectious mononucleosis. All three patients revealed T-cell abnormalities including inverted CD4/CD8 and increased CD8(+) T-cell numbers. The number of IFN-gamma-producing T cells were markedly increased in the two patients studied so far. In addition, patient 2 showed mainly T cells, instead of B cells, to be infected with the EBV. Apart from an uncle of patient 3, who died of malignant lymphoma, family history was unremarkable in all cases. All three patients exhibited mutations in the SH2D1A gene, establishing the diagnosis of XLP. Protein expression was found on immunoblot analysis in one patient with a missense mutation. Development of persistent hypogammaglobulinemia after severe primary EBV infection seems to be a specific diagnostic sign for XLP even in males with unremarkable family history.

X-linked lymphoproliferative disease: genetic lesions and clinical consequences

X-linked lymphoproliferative disorder (XLP) was first described almost 30 years ago; remarkably, the three major manifestations of XLP, fulminant infectious mononucleosis (FIM), lymphoma, and dysgammaglobulinemia, are all described in the report of the initial kindred. Subsequent establishment of an XLP registry has led to recognition of more unusual phenotypes in affected males; concurrently, much progress has been made in caring for boys with XLP, including treatment for the three major phenotypes, and curative bone marrow transplantation (BMT). The immunologic and genetic mechanisms resulting in XLP have also been intensively studied. Several years ago, the gene defective in XLP was identified as SAP (SLAM-associated protein), and recent data suggest that SAP plays a broad role in immune signaling. Here, we review the clinical manifestations and therapy of XLP, and briefly summarize recent research into the structure and function of SAP.

Infection in patients with primary immunodeficiency disorders

Recent advances in the understanding of the molecular basis of primary immunodeficiency disorders are reviewed, with particular emphasis on how these provide insights to the normal host's handling of particular microbes. Also reviewed are a number of reports on series of patients with these disorders, documenting the incidence and nature of the infective complications that occur and the effectiveness of treatment strategies.