Notes on Primary Immunodeficiency

  >   Rahul's Noteblog   >   Notes on Immunology   >   Notes on Primary Immunodeficiency

Primary Immunodeficiency

• These diseases are caused by defects in the body's immune system.

• The most popular PI diseases are: X-linked Agammaglobulinemia (Bruton's Disease), Common Variable Immune deficiency, (Hypogammaglobulinemia), Selective IgA Deficiency Severe Combined Immune Deficiency.

• Many hereditary PI diseases are silent killers if left untreated.

Five main Primary Immunodeficiency Diseases:

• B cell (antibody) deficiencies, combined T cell and B cell (antibody) deficiencies, T cell deficiencies, defective phagocytes, complement deficiencies, deficiencies/cause unknown.

• B-cell malfunction diseases: X-Linked Agammaglobulinemia (XLA), Common Variable Immunodeficiency, Hyper IgM Syndrome, Selective IgA Deficiency, IgG Subclass Deficiency, Severe Combined Immunodeficiency (SCID), Partial Combined Deficiencies, Wiskott-Aldrich Syndrome (WAS), Ataxia-Telangiectasia (AT).

• T-cell malfunction diseases: DiGeorge Anomaly, Cartilage Hair Hypoplasia.

• Phagocyte malfunction diseases: Chronic Granulomatous Disease (CGD), Leukocyte Adhesion Defect (LAD), Chediak-Higashi Syndrome (CHS).

• Diseases of unknown or lesser known origin: Hyper-IgE Syndrome, Chronic Mucocutaneous Candidiasis.

Hyper-IgM (HIM):

• This is a rare disease characterized by overproduction of IgM.

• Individuals are susceptible to bacterial infections, autoimmune disorders, and cancers - targeting tissues and mucosal surfaces.

• The gene TNFSF5 that codes for protein CD154 is mutated.

• The normal immune response: B-cells first produce IgM antibodies that protect tissues and mucosal surfaces.

• With the defective TNFSF5 gene, B-cells cannot communicate with T-cells.

• Treatment: prompt treatment of infections, and IgG therapy through IV.

• Common infections are by Pneumocystis and Cryptosporidium species.

Severe Combined Immunodeficiency:

• Caused by defects in both T and B cell systems.

• Infections occur in infancy.

• Common infections include: pneumonia, meningitis or bloodstream infections.

• Defects in purine salvage pathway, stem cells, cell-surface molecules, IL2.

• Also associated with Letterer-Siwe Syndrome (Omenn Disease).

• These types of infections occur: Fungal (oropharynx, esophagus, skin), Viral (adenovirus, CMV, HSV, measles, rotavirus, varicella), and Bacterial (chronic progressive pneumonitis).

Opportunistic Infections in Immunodeficiency:

• Fungal (chronic mucocutaneous candidiasis, systemic candidiasis).

• Bacterial/Viral Respiratory: pneumonia, pneumonitis, chronic cough.

• Bacterial/Viral Gastrointestinal: esophagitis, gastroenteritis, chronic diarrhea, hepatitis, wasting, distended abdomen.

• Other general diseases include: Graft vs host dieease, leukemia, lymphoma, absence of tonsils, etc.

• Decrease in serum T/B cells.

• Pulmonary infiltrates may be seen in X-rays, absence of thymic shadow.

XLA X Linked Agammaglobulinaemia (Brutons Agammaglobulinaemia):

• Absence of all antibodies.

• There are recurrent bacterial infections involving: encapsulated bacteria such as S. pneumoniae and H. influenzae.

• Diagnosed until age 2-4 years by confirmation of absence of Abs.

• Treatment: antimicrobial therapy with adequate Ig replacement.

• Babies have a chance of developing Pneumocysttis carinii pneumonia.

IgA Deficiency

• Most patients are asymptomatic.

• Anti-IgA antibody reaction occurs in blood transfusions.

Common Variable Immunodeficiency Disease (CVID):

• Deficiency of all, or of some Ig classes, or subclasses.

Defects in Cellular Immunity:

• Defective or no T-cells.

DiGeorge Syndrome:

• Defect in branchial arch embryogenesis.

• No thymus and other organs.

• Defective or no T-cells.

Defective Phagocytes Cause Diseases:

• Chronic Granulomatous Disease.

• Very rare disease with recurrent bacterial infections in children.

• Enlarged lymph nodes with granulomas and scarred skin.

Complementary Deficiency:

• Defective or missing complement system.

• People may have different versions of C4 complement component: C4A and C4B.

• There is increased risk of infections and autoimmune disease.

Additional Readings:

Basic Immunology

1. Introduction to Immunology
2. Cells of Immunology
3. Selection of Lymphocytes
4. Primary Response to Antigen
5. Antigen Processing and Presentation
6. Humoral Effector Mechanism Generator
7. Cell-Mediated Effector Mechanism Generator
8. Vaccination and Immunotherapy
9. Immunodeficiency Diseases
10. Acquired Immunodeficiency Syndrome
11. Hypersensitivities and Autoimmunity Diseases
12. Immunology of Transplantation
13. Immunology of Cancer
14. Immunology Laboratory Technology
15. Acquired Immunity
16. Type II Hypersensitivity Reaction
17. Hypersensitivity Reactions
18. Primary Immunodeficiency
19. Secondary Immunodeficiency
20. Type III Hypersensitivity Reaction
21. Type IV Hypersensitivity Reaction
22. Type V Hypersensitivity Reaction
23. Tumor Immunology
24. Images of Antibodies
25. Th1 vs Th2 cells

Related Topics

1. Histology of Lymphoid Tissue

Medical Images

Useful Medical Images & Diagrams (link opens in a new window)

Random Pages:

Voices from Hell: My Experience in Mussoorie, India Review of eBoundhost VPS hosting
Video of me playing Yanni`s "Nightingale" Notes on Lymphoid Tissue
Notes on Back and Nervous System Notes on Rickettsia
Notes on Energy Metabolism How to Reduce Blood Pressure without Medications?
Differentiation and Anatomy of a Blastocyst Digestion FAQ, Defecation reflex, etc.
Notes on Basic Gastrointestinal Physiology Corporate Failure: The Enron Case
Body-Mass-Index, Waist-to-Height Ratio, Body Fat, Basal Metabolic Rate Calculator What is an ELEK`s Test?
Why did I decide to become a doctor? Medical School Admissions Essay Video: Titanic Piano Theme: The Portrait
Corporate Failure: The Enron Case My Experience during the Iraqi Invasion of Kuwait
USMLE Blood Lab Values Regulation of Heart Rate by Autonomic Nervous System
Images of Antibodies Video of me playing Yanni`s "Nightingale"
Notes on Integument Differentiation and Anatomy of a Blastocyst
Notes on Cell Components Notes on Nervous Tissue
Voices from Hell: My Experience in Mussoorie, India Video of Cardiology Examination in a Clinical Setting

Please Do Not Reproduce This Page

This page is written by Rahul Gladwin. Please do not duplicate the contents of this page in whole or part, in any form, without prior written permission.