Filion et al reported features that help to distinguish common variable immunodeficiency (CVID) from IgG deficiency. The authors are from Mount Sinai in New York, University of Montreal and Dartmouth-Hitchcock Concord Medical Center.
Overlapping features:
(1) low IgG concentrations (more profound in CVID)
(2) sinusitis and pneumonia (sinopulmonary infections)
Features of CVID:
(1) higher rate of bronchiectasis
(2) higher rate of autoimmune disease and autoimmune cytopenias
(3) higher rate of interstitial lung disease
(4) higher rate of granulomatous diseases
(5) higher rate of splenomegaly
(6) higher rate of lymphoid malignancies
(7) higher rate of enteropathy
(8) lower percentage of memory B cells
(9) lower percentages of isotype switched-memory B cells (CD19+ CD27+ IgD-)
(10) lower CD4+ T cells
(11) greater unresponsiveness to most vaccines
(12) lower concentrations of IgA and IgM