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Normal Host Defense and Primary Immunodeficiency

Functions of the Vertebrate Immune System

Exclude, eliminate or kill foreign invasion

Develop memory and amplified recall response

Deficits result in

Increased frequency or severity of infections with pathogens

Infections with nonpathogenic, opportunistic organisms

Components of Innate (Preexisting) Immunity

Barriers - skin and mucus membranes, normal flora, spleen

Opsonins - complement, collectins, CRP

Phagocytes - neutrophils, monocytes, macrophages and NK cells

Components of Antigen-specific Immunity

Host Defense Immunodeficiency

CD4 T cells (helper/master control)

Cytokines -IL-2, IFN-d TNF-a/IL-4, IL-5

Cognate help for APC/B cells via CD40 ligand

CD8 and 75 T Cells

Recurrent/Persistent Sinopulmonary and Ear InfectionsIcon

 Without GI Infections

Suspect deficit in innate, respiratory mucosal defenses, allergy or humoral immunity

With GI Infections

Suspect host defense, immunodeficiency antibody deficiency

IconIntrinsic Defenses of the Respiratory Mucosa/Lung