Decreased CD27+ Memory B cells in DiGeorge Anomaly

Abstract

ABSTRACT

Patients with DiGeorge anomaly (DGA) have a variety of B-cell immune deficiencies, including IgA deficiency and impaired polysaccharide antibody responses. CD27+ memory B cells have been found to be decreased in a variety of B-cell immunodeficiencies, such as selective antibody deficiency (SAD). We evaluated for a correlation between reduced CD27+ memory B cells and impaired polysaccharide antibody responses in patients with DGA. A retrospective analysis of DGA patients referred for recurrent sinopulmonary infections was performed. Twenty-one patients with DGA (62% male and median age was 5 ± 0.8 years) were evaluated. Six patients had reduced CD3+ T cells, and two patients had reduced CD4+ T cells, but none had opportunistic infections. B-cell numbers and percentages were normal in all patients, but the percentages of memory CD27+ B cells were decreased compared to normal values, 12 ± 2% versus 34%. CD27+ B cells were <15% in 86% of patients. Eighty-one percent of patients had reduced protective antibody responses to <70% of Streptococcus pneumoniae serotypes. Immunoglobulin levels were normal in all patients except one with selective IgA deficiency. Seventy-five percent of the patients had both decreased CD27+ B cells and decreased antibody responses to S. pneumoniae immunizations. In addition, patients who were treated with intravenous immunoglobulin (IVIG), had CD19+ B cells ≤7%, and 12 of 14 patients treated with prophylactic antibiotics had CD19+ B cells ≤14%. There was an association of anti-S. pneumonia antibody responses and percentages of CD27+ B cells in 86% of patients. The percentages of CD27+ memory B cells and antibody responses to S. pneumoniae were associated in patients with DGA. Decreased memory B cells may be involved in the pathogenesis of SAD, as seen in patients with DGA, and may be predictive of increased susceptibility to infections.