B-cell lymphoma associated with DiGeorge syndrome

Lymphoma in Partial DiGeorge Syndrome: Report of 2 Cases

Primary immunodeficiency diseases are associated with an increased tendency for noninfectious complications of autoimmunity and malignancy, particularly leukemia and lymphoma. The mechanisms of immune dysregulation have been linked to the combination of dysregulated immune cells and environmental factors such as infections. In particular, dysfunction in T-cell subsets and Epstein-Barr virus contributes to the development of autoimmunity and lymphoproliferative disease in primary immunodeficiency diseases. There are scant reports of patients with partial DiGeorge syndrome and Epstein-Barr virus-driven lymphoma. We report 1 patients with partial DiGeorge syndrome who developed lymphoma, and review reported cases in the literature.

The immune deficiency of chromosome 22q11.2 deletion syndrome

The syndrome originally described by Dr. Angelo DiGeorge had immunodeficiency as a central component. When a 22q11.2 deletion was identified as the cause in the majority of patients with DiGeorge syndrome, the clinical features of 22q11.2 deletion syndrome became so expansive that the immunodeficiency became less prominent in our thinking about the syndrome. This review will focus on the immune system and the changes in our understanding over the past 50 years. Initially characterized as a pure defect in T cell development, we now appreciate that many of the clinical features related to the immunodeficiency are well downstream of the limitation imposed by a small thymus. Dysfunctional B cells presumed to be secondary to compromised T cell help, issues related to T cell exhaustion, and high rates of atopy and autoimmunity are aspects of management that require consideration for optimal clinical care and for designing a cogent monitoring approach. New data on atopy are presented to further demonstrate the association.

Pulmonary extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue associated with granulomatous inflammation in a child with chromosome 22q11.2 deletion syndrome (DiGeorge syndrome)

Patients with immunodeficiency disorders have an increased incidence of lymphoproliferative disorders; however, only 4 such patients with DiGeorge/chromosome 22q11.2 deletion syndrome have been reported. We report a case of a pulmonary Epstein-Barr virus-negative extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue in a child with this syndrome.

Dysplastic changes in the peripheral blood of children with microdeletion 22q11.2

Myelodysplasia refers to abnormal morphology of the bone marrow and/or peripheral blood. This condition is frequently due to myelodysplastic syndrome; however, myelodysplasia is caused by a variety of factors and is not always a sign of pre-malignant disease. We observed myelodysplastic changes in peripheral blood smears and bone marrow specimens from a patient who had chromosomal microdeletion 22q11.2 (del22q11.2). We then investigated such changes in several other patients who were newly diagnosed with del22q11.2 (n = 5 total, including the index case) and compared the findings to those in four sets of controls without this chromosomal abnormality. Specifically, the controls were children with conotruncal heart defects (n = 3); otherwise healthy children with bacterial (n = 4) or viral infection (n = 4); and healthy children (n = 4). The myelodysplasia scores in the myeloid cells and eosinophils of the children with del22q11 were higher than those in all four of the control groups. Myelodysplastic changes in the peripheral blood of children with del22q11.2 have not been reported previously. We believe that certain gene(s) in the deleted region may be responsible for the myelodysplastic changes that we observed in our patients with this chromosomal abnormality.

Epstein-Barr virus in patients with immunodeficiency disorders

The Epstein-Barr virus (EBV), one of eight known human herpesviruses, causes a wide spectrum of diseases under certain conditions. In particular, in the setting of immunodeficiency, which includes primary or secondary/acquired immunodeficiencies, they have been increasingly reported. The major clinical phenotype is the EBV genome-positive lymphoproliferative disorder, which ranges from benign lymphoproliferation to malignant lymphoma with cytogenetic alterations. Severe or fatal infectious mononucleosis may develop in some patients with immunodeficiencies such as X-linked lymphoproliferative disease.