Table 1.

European Society for Immunodeficiency (ESID), US practice parameters, and International Consensus Document (ICON) criteria for the diagnosis of specific antibody deficiency (SAD) and common variable immunodeficiency (CVID) (3, 12, 26).

	SAD		CVID
	ESID criteria (3)	US practice parameters (12)	ESID criteria (3)	US practice parameters (12)	ICON criteria (26)
Clinical presentation	Recurrent or severe bacterial infections	Recurrent respiratory tract infections	At least one of the following: increased susceptibility to infection autoimmune manifestations granulomatous disease unexplained polyclonal lymphoproliferation affected family member with antibody deficiency	Recurrent and chronic bacterial respiratory tract infections are the most frequent infectious complications Common pathogens include encapsulated or atypical bacteria Recurrent and/or persistent viral respiratory tract infections are also increased	Most patients will have at least 1 characteristic clinical manifestation (infection, autoimmunity, lymphoproliferation) Diagnosis may be conferred on asymptomatic individuals who fulfill other criteria listed below, especially in familial cases
Antibody levels	Normal IgG, IgA and IgM, and IgG subclass levels	Normal IgG, IgA and IgM, and IgG subclass levels	Marked decrease of IgG and IgA with or without low IgM levels	Low IgG and IgA levels with normal or low IgM levels	Serum IgG level must be below local/regional clinical laboratory norms Low IgA or IgM levels (low IgA preferred)
Response to vaccines	Profound alteration of the antibody responses to polysaccharide vaccine	Impaired response to pneumococcal capsular polysaccharide	At least one of the following: poor antibody response to vaccines (and/or absent isohemagglutinins) low switched memory B-cells	Impaired vaccine response	Impaired vaccine response
B-cells	Not considered	Normal B-cell levels	Possibly low switched memory B-cells (see criteria above)	Normal or low B-cell levels	Not considered
T-cells	Exclusion of T-cell defect	Not considered	No evidence of profound T-cell deficiency	Not considered	In patients with IgG >100 mg/dL, demonstrable impairment of response to T-cell antigens
Other diagnostic criteria	None	Patients older than 2 years	Secondary causes of hypogammaglobulinemia have been excluded Diagnosis is established after the 4th year of life (but symptoms may be present before)	Consider possible transient hypogammaglobulinemia Patients older than 4 years No genetic lesions or other causes of primary or secondary antibody deficiency	Other causes of hypogammaglobulinemia must be excluded