IMMUNODEFICIENCY 1.0 Flashcards
INTRO-INDICATIONS OF IMMUNODEFICIENCY DISORDERS
Classification of Immunodeficiency
a. Primary
b. Secondary
Types of immunodeficiency
a. Humoral (B-cell) Immunodeficiency
b. Cellular (T-cell) Immunodeficiency
c. Combined B-cell and T-Cell Deficiency
d. Other Types
* Iatrogenic Deficiency
* Nutritional Deficiency
Refers to a state in which the immune system’s ability to fight infections and diseases is compromised or entirely absent.
IMMUNODEFICIENCY
This condition can lead to increased susceptibility to infections, more severe illnesses, and a higher risk of developing certain cancers.
IMMUNODEFICIENCY
Refers to a condition characterized by an innate, acquired, or induced inability to develop a normal immune response.
IMMUNODEFICIENCY
TYPES OF IMMUNODEFICIENCY:
- Usually present at birth and are genetic disorders that are usually hereditary.
- Typically become evident during infancy or childhood.
- All are relatively rare!
PRIMARY IMMUNODEFICINECY
There are more than 100 primary immunodeficiency disorders.
TYPES OF IMMUNODEFICIENCY:
- Generally develop later in life.
- Result from use of certain drugs or from another disorder.
SECONDARY IMMUNODEFICIENCY
They are more common than primary immunodeficiency disorders.
TYPES OF IMMUNODEFICIENCY:
These are immunodeficiency disorders that a person is born with, usually due to genetic defects that affect the development or function of the immune system.
PRIMARY IMMUNODEFICIENCY
PRIMARY IMMUNODEFICIENCY, classified based on which part of the immune system is affected.
- Humoral (B-cell) Immunodeficiencies
- Cellular (T-cell) Immunodeficiencies
- Combined T-cell and B-cell Immunodeficiencies
PRIMARY IMMUNODEFICIENCY:
- Group of disorders where there is a deficiency or dysfunction in B cells, the immune cells responsible for producing antibodies (immunoglobulins).
- These antibodies are crucial for identifying and neutralizing pathogens like bacteria and viruses.
Humoral (B-cell) Immunodeficiencies
PRIMARY IMMUNODEFICIENCY:
Genetic Defects under Humoral (B-cell) Immunodeficiencies
- X - linked Agammaglobulinemia
- Selective IgA Deficiency
PRIMARY IMMUNODEFICIENCY:
- A genetic defect in the BTK gene (encodes Bruton’s tyrosine kinase that is essential for B cell development).
- Patients have very few or no B cells, leading to almost no antibody production.
- Recurrent bacterial infections, especially of the respiratory and gastrointestinal tracts, beginning in infancy.
Genetic Defects under Humoral (B-cell) Immunodeficiencies
X - linked Agammaglobulinemia
BTK gene is located on the X chromosome, XLA follows an X-linked recessive inheritance pattern.
* Males do not have a second X chromosome to compensate for the defective gene.
* Females are usually carriers because they have one normal BTK gene on their other X chromosome, which compensates for the defective gene. However, carriers rarely show symptoms.
PRIMARY IMMUNODEFICIENCY:
- The mutation in the BTK gene leads to a failure in the development of B cells, the cells responsible for producing antibodies.
- Without functional B cells, the body cannot produce immunoglobulins.
Genetic Defects under Humoral (B-cell) Immunodeficiencies
X - linked Agammaglobulinemia
The term “agammaglobulinemia” refers to the absence or severe deficiency of immunoglobulins (antibodies) in the blood.
It is a crucial antibody found in mucous membranes lining the respiratory and gastrointestinal tracts, as well as in saliva, tears, and breast milk. It plays a key role in the first line of defense against pathogens entering the body through these routes
IgA
Individuals with selective IgA deficiency have low or undetectable levels of IgA, which impairs their mucosal immunity.
PRIMARY IMMUNODEFICIENCY:
▪ Commonly associated with:
* normal B lymphocytes in peripheral blood
* normal CD4+ and CD8+ T cells
* usually, normal neutrophil and lymphocyte counts
▪ Many are asymptomatic.
▪ Some people may have recurrent respiratory infections (e.g., sinusitis, bronchitis) or gastrointestinal infections due to the lack of IgA.
Genetic Defects under Humoral (B-cell) Immunodeficiencies
IgA Deficiency
PRIMARY IMMUNODEFICIENCY:
- Group of disorders where the body has an inadequate or dysfunctional T-cellmediated immune response.
- T cells are a type of lymphocyte (white blood cell) essential for coordinating the immune system’s response to infections, especially those caused by viruses, fungi, and certain bacteria.
Cellular (T-cell) Immunodeficiencies
DiGeorge Syndrome
When T-cell function is impaired, the body’s ability to fight infections and regulate immune responses is significantly compromised.
PRIMARY IMMUNODEFICIENCY:
- Caused by a deletion in the 22q11.2 region of chromosome 22. This region contains several genes crucial for normal development, and the loss of these genes leads to the various manifestations of the syndrome.
- Leads to thymic hypoplasia or aplasia (underdevelopment or absence of the thymus gland).
- The thymus is where T cells mature, so its underdevelopment leads to T-cell deficiency
Cellular (T-cell) Immunodeficiencies
DiGeorge Syndrome
- Cardiac Abnormalities: TOF, VSD
- Cleft Palate
- Facial Features: Long face, almond-shaped eyes, a broad nasal bridge, small mouth, and a small chin.
- Thymic Hypoplasia or Aplasia:.
- Hypocalcemia: Due to underdeveloped parathyroid glands
- Developmental Delays: Delays in speech, motor skills, and learning.
- Behavioral and Psychiatric Disorders: ADHD
PRIMARY IMMUNODEFICIENCY:
- Group of primary immunodeficiency disorders characterized by defects in both T-cell and B-cell functions.
- These immunodeficiencies severely compromise the immune system, leading to an increased susceptibility to a wide rangeof infections, including bacterial, viral, and fungal infections.
- These conditions are usually congenital (present from birth) and are often lifethreatening without early diagnosis and treatment.
Combined T-Cell and B-Cell Immunodeficiencies
PRIMARY IMMUNODEFICIENCY:
Groups of Genetic Disorder under Combined T-Cell and B-Cell Immunodeficiencies
(Syndromes)
- Severe Combined Immunodeficiency Syndrome (SCIDS)
- Wiskott-Aldrich Syndrome
PRIMARY IMMUNODEFICIENCY: | Combined T and B-Cell Immunodeficiencies
- A group of genetic disorders that result in little or no immune function due to profound defects in both T cells and B cells.
- Most forms of these are inherited in an X-linked or autosomal recessive manner.
Severe Combined Immunodeficiency Syndrome (SCIDS)
PRIMARY IMMUNODEFICIENCY: | Combined T and B-Cell Immunodeficiencies
FEATURES:
* Severe Infections: Infants with this present with severe, recurrent infections within the first few months of life. These can include pneumonia, chronic diarrhea, and opportunistic infections like Pneumocystis jirovecii pneumonia.
* Failure to Thrive: Affected infants may fail to gain weight and grow as expected.
* Absence of Lymphoid Tissue: Physical examination may reveal absent or small tonsils
Severe Combined Immunodeficiency Syndrome (SCIDS)
PRIMARY IMMUNODEFICIENCY: | Combined T and B-Cell Immunodeficiencies
A rare X-linked genetic disorder characterized by a triad of symptoms: eczema, thrombocytopenia (low platelet count), and combined immunodeficiency, affecting both Tcell and B-cell functions.
Wiskott-Aldrich Syndrome
The syndrome was first described by Dr. Alfred Wiskott in 1937 and further detailed by Dr. Robert Aldrich in 1954.
PRIMARY IMMUNODEFICIENCY: | Combined T and B-Cell Immunodeficiencies
An X-linked recessive manner, meaning it primarily affects males, while females are usually carriers
Wiskott-Aldrich Syndrome
Caused by mutations in the WAS gene, which provides instructions for making the WiskottAldrich syndrome protein (WASP).
It is involved in the regulation of the cytoskeleton of cells, particularly in immune cells like T cells, B cells, and platelets.
WiskottAldrich Syndrome Protein(WASP)
Classification of Immunodeficiency:
- Refers to an acquired impairment of the immune system that occurs due to external factors, rather than a congenital or genetic cause.
- These factors can weaken the immune response, making the body more susceptible to infections, diseases, and other health issues.
SECONDARY IMMUNODEFICIENCY
SECONDARY IMMUNODEFICIENCY | Infections
The most well-known cause, where the Human Immunodeficiency Virus (HIV) attacks and destroys CD4+ T cells, leading to a weakened immune system and, if untreated, progressing to Acquired Immunodeficiency Syndrome (AIDS).
HIV/AIDS
SECONDARY IMMUNODEFICIENCY | Infections
Persistent infections can exhaust the immune system and lead to secondary immunodeficiency.
Chronic or severe infections
SECONDARY IMMUNODEFICIENCY | Malnutrition
Lack of essential nutrients weakens the immune system, particularly affecting the production and function of immune cells.
Protein-energy malnutrition
SECONDARY IMMUNODEFICIENCY | Malnutrition
Deficiencies in vitamins like A, C, D, and minerals like zinc and iron can impair immune responses.
Vitamin and mineral deficiencies
SECONDARY IMMUNODEFICIENCY | Medical Treatment
Used to treat cancer, it can damage or destroy bone marrow cells, reducing the production of immune cells.
Chemotherapy
SECONDARY IMMUNODEFICIENCY | Medical Treatment
Medications used to prevent organ transplant rejection or treat autoimmune diseases suppress the immune system, making the body more vulnerable to infections.
Immunosuppressive Drugs
SECONDARY IMMUNODEFICIENCY | Medical Treatment
Used in cancer treatment, it can damage the bone marrow and reduce immune cell production.
Radiation Therapy
SECONDARY IMMUNODEFICIENCY | Chronic Diseases
High blood sugar levels can impair the immune system’s ability to function properly.
Diabetes
SECONDARY IMMUNODEFICIENCY | Chronic Diseases
Can lead to a buildup of waste products that suppress immune function
Kidney Disease
SECONDARY IMMUNODEFICIENCY | Chronic Diseases
Impairs the production of proteins critical for immune function.
Liver Disease
SECONDARY IMMUNODEFICIENCY
The immune system naturally weakens with age, leading to a decreased ability to fight infections and diseases.
Aging
SECONDARY IMMUNODEFICIENCY:
Chronically, it can suppress the immune system by increasing the production of cortisol, a hormone that can inhibit immune responses.
Stress
These factors under SECONDARY IMMUNODEFICIENCY can weaken the immune response:
- Infections
- Malnutrition
- Medical Treatment
- Chronic Diseases
- Aging
- Stress
What are the different CONSEQUENCES of SECONDARY IMMUNODEFICIENCY
- Increased Susceptibility to Infections
- Delayed Recovery
- Increased Risk of Cancer
CONSEQUENCE of SECONDARY IMMUNODEFICIENCY
Individuals with secondary immunodeficiency are more prone to frequent and severe infections, including opportunistic infections.
Increased Susceptibility to Infections
CONSEQUENCE of SECONDARY IMMUNODEFICIENCY
The body’s ability to recovery from infections and injuries is often compromised.
Delayed Recovery
CONSEQUENCE of SECONDARY IMMUNODEFICIENCY
The weakened immune system may not be able to detect and destroy cancer cells as effectively, leading to an increased risk of malignancies
Increased Risk of Cancer
RISK FACTORS OF IMMUNODEFICIENCY DISORDERS
- Family History
- Decreased Functional Capacity of I.S.
- Aging
- Low Protein Intake
- Lack of Sleep
- Immunosuppressive
INDICATIONS OF IMMUNODEFICIENCY DISORDERS
- Multiple infections despite aggressive treatment
- Infections with unusual or opportunistic organisms
- Failure to thrive or poor growth
- Positive family history
