Children diagnosed with common variable immune deficiency show distinct T cell maturation phenotypes when compared with adults (P3333)

Abstract

Abstract INTRODUCTION: Common variable immune deficiency (CVID) is considered primarily a B cell disorder characterized by low immunoglobulin levels, defective specific antibody production and susceptibility to sinopulmonary infections. Recent studies have implicated T cells in the pathogenesis of CVID. OBJECTIVES: To compare T cell maturation in children and adults with CVID. METHODS: Through PRIMES (Canadian Primary IMmunodeficiency Evaluation Study) registry, we recruited eight children and ten adults with CVID. T cell phenotype was assessed by flow cytometry. Patients were compared to healthy controls (thirteen children and ten adults). Wilcoxon Rank Sum test was used to assess differences in T cell subsets. RESULTS: Total lymphocyte count, CD3, CD4 and CD8 lymphocytes were decreased in children with CVID compared to controls (p=0.0006, p=0.0003, p=0.0003, p=0.03). Percentage and absolute numbers of naïve (p=0.012, p=0.002) and absolute numbers of memory cells (p=0.001) were decreased in children with CVID. However, there were no statistical differences between adults with CVID and healthy controls. DISCUSSION: Our data shows decreased T cell subsets in childhood CVID while levels in adults were normal. Studies assessing temporal trends in T cell subsets are required to determine if these differences in children are due to age-related compensatory mechanisms or if different mechanisms play a role in the pathogenesis of childhood versus adult onset CVID.