Immunodeficiency

Immunodeficiency is a topic covered in the Washington Manual of Medical Therapeutics.

To view the entire topic, please or .

The Washington Manual of Medical Therapeutics helps you diagnose and treat hundreds of medical conditions. Consult clinical recommendations from a resource that has been trusted on the wards for 50+ years. Explore these free sample topics:

-- The first section of this topic is shown below --

General Principles

Definition

  • Primary immunodeficiencies (PIDs) are disorders of the immune system that result in an increased susceptibility to infection.
  • Secondary immunodeficiencies are also disorders of increased susceptibility to infection but are attributable to an external source.

Classification

PIDs can be organized by the defective immune components with considerable heterogeneity in each disorder.

  • Predominantly antibody deficiencies: The defect is primarily in the ability to make antibodies.
    • Common variable immune deficiency (CVID)
    • X-linked (Bruton) agammaglobulinemia
    • IgG subclass deficiency
    • Specific antibody deficiency
    • Hyper IgM syndrome
    • Selective IgA deficiency
  • Combined immunodeficiencies and syndromes: The defect results in deficiencies in both cellular and humoral immune responses.
    • Severe combined immunodeficiencies
    • DiGeorge syndrome
    • Hyper-IgE (Job) syndrome
  • Defects of innate immunity: Defects in germline-encoded receptors and downstream signaling pathways
    • Deficiency of Toll-like receptor signaling
    • Mendelian susceptibility to mycobacterial diseases (MSMD)
    • Natural killer (NK) cell deficiency
    • Phagocytic cell deficiencies
    • Chronic granulomatous disease (CGD)
  • Complement deficiencies.
  • Diseases of immune dysregulation: Autoimmunity and lymphoproliferation are characteristic manifestations in these disorders.

Epidemiology

  • Secondary immunodeficiency syndromes, particularly HIV/AIDS, are the most common immunodeficiency disorders.
  • The estimated prevalence of PIDs is approximately 1 in 1200 live births.
  • Most PIDs presenting in adulthood are humoral immune defects affecting antibody production.

Etiology

  • Predominantly antibody immune deficiencies are thought to be caused by defects in B-cell maturation. Combined immunodeficiencies are caused by defective T-cell–mediated immunity and associated antibody deficiency.
  • A variety of genetic mutations have been associated with specific PID syndromes.
  • Secondary immunodeficiencies can be caused by medications (chemotherapy, immunomodulatory agents, corticosteroids), infectious agents (e.g., HIV), malignancy, antibody loss (e.g., nephrotic syndrome, protein losing enteropathy, or consumption during a severe underlying infection), autoimmune disease (e.g., systemic lupus erythematosus, rheumatoid arthritis), malnutrition (vitamin D), and other underlying diseases (e.g., diabetes mellitus, cirrhosis, uremia).

-- To view the remaining sections of this topic, please or --

General Principles

Definition

  • Primary immunodeficiencies (PIDs) are disorders of the immune system that result in an increased susceptibility to infection.
  • Secondary immunodeficiencies are also disorders of increased susceptibility to infection but are attributable to an external source.

Classification

PIDs can be organized by the defective immune components with considerable heterogeneity in each disorder.

  • Predominantly antibody deficiencies: The defect is primarily in the ability to make antibodies.
    • Common variable immune deficiency (CVID)
    • X-linked (Bruton) agammaglobulinemia
    • IgG subclass deficiency
    • Specific antibody deficiency
    • Hyper IgM syndrome
    • Selective IgA deficiency
  • Combined immunodeficiencies and syndromes: The defect results in deficiencies in both cellular and humoral immune responses.
    • Severe combined immunodeficiencies
    • DiGeorge syndrome
    • Hyper-IgE (Job) syndrome
  • Defects of innate immunity: Defects in germline-encoded receptors and downstream signaling pathways
    • Deficiency of Toll-like receptor signaling
    • Mendelian susceptibility to mycobacterial diseases (MSMD)
    • Natural killer (NK) cell deficiency
    • Phagocytic cell deficiencies
    • Chronic granulomatous disease (CGD)
  • Complement deficiencies.
  • Diseases of immune dysregulation: Autoimmunity and lymphoproliferation are characteristic manifestations in these disorders.

Epidemiology

  • Secondary immunodeficiency syndromes, particularly HIV/AIDS, are the most common immunodeficiency disorders.
  • The estimated prevalence of PIDs is approximately 1 in 1200 live births.
  • Most PIDs presenting in adulthood are humoral immune defects affecting antibody production.

Etiology

  • Predominantly antibody immune deficiencies are thought to be caused by defects in B-cell maturation. Combined immunodeficiencies are caused by defective T-cell–mediated immunity and associated antibody deficiency.
  • A variety of genetic mutations have been associated with specific PID syndromes.
  • Secondary immunodeficiencies can be caused by medications (chemotherapy, immunomodulatory agents, corticosteroids), infectious agents (e.g., HIV), malignancy, antibody loss (e.g., nephrotic syndrome, protein losing enteropathy, or consumption during a severe underlying infection), autoimmune disease (e.g., systemic lupus erythematosus, rheumatoid arthritis), malnutrition (vitamin D), and other underlying diseases (e.g., diabetes mellitus, cirrhosis, uremia).

There's more to see -- the rest of this entry is available only to subscribers.