Table 4

Key characteristics of XLA and CVID
	XLA	CVID

Age of onset	usually by 9–18 months	usually 2nd – 4th decade

Family Hx of immunodeficiency	usually +ve	variable*

Inheritance	x-linked recessive	variable

Diagnosis
Lymph nodes/tonsils	absent tonsillar tissue	normal tonsillar tissue
CD19⁺B cell numbers	markedly decreased/absent	normal/low
CD4⁺T cell numbers	Normal	Variable**
CD8⁺T cell numbers	Normal	Variable**
CD4⁺CD8⁺ratio	Variable	often decreased
Specific Antibody titers	absent	decreased/absent
Mutations reported	Btk	TACI, ICOS, BAFF-R, CD19⁺

Common Complications	Infections	Infections
	Allergy/Atopy	Allergy/Atopy
	CEMA, VAPP	-----
	Autoimmunity	Autoimmunity
	Malignancy	Malignancy

Treatment	IGIV	IGIV
	Symptomatic care	Symptomatic care***

Some familial clustering has been described in the literature, possibly associated with Class II MHC gene complex CD4⁺and CD8⁺numbers may be low or normal ** Symptomatic care includes antimicrobials, surgical drainage, nebulizer treatment for wheezing, allergy management, avoidance, nutrition, etc. Abbreviations: TACI, Transmembrane activator and calcium-modulator and cyclophilin ligand interactor, Btk, Bruton's tyrosine kinase, ICOS, inducible costimulatory receptor, CEMA, chronic enteroviral meningoencephalitis, VAPP, vaccine-associated paralytic poliomyelitis, IGIV, intravenous immunoglobulin.
Sigmon et al. Clinical and Molecular Allergy 2008 6:5 doi:10.1186/1476-7961-6-5