Immunodeficiency Disorders Flashcards
Primary immunodeficiency
Caused by mutations and. Are present at birth
Secondary immunodeficiencies
Acquired, due to diseases, environmental factors, medical intervention
Histological Abnormalities in B cell deficiency
Absent or reduced germinal centers, reduced Ig levels
Infectious consequences of B cell deficiency
Progenic bacterial infections, extracellular
Infectious consequences of T cell deficiency
Viral and other intracellular microbial infections, virus associated malignancies
Innate immune system infectious consequences
Variable, progenic bacterial infections
Examples of neutrophil deficiency (4)
- Neutropenia
- Defective opsonization
- Defective killing of bacteria
- Defect in neutrophil migration
Neutrophil defect of killing bacteria examples (2)
- Chronic Granulomatous disease (GCD)
- Chediak-Higashi syndrome
Defective neutrophil migration example
Leukocyte adhesion deficiency (LAD)
Chronic granulomatous disease
X linked, inability to generate superoxide anion due to NADPH oxidase and cytochrome n defect, leads to recurrent infection with skin abscesses, chronic granulomas
Leukocyte adhesion deficiency
Failure of neutrophils to emigrate out of vessels and towards antigen, failure of CD8+ to bind, recurrent bacterial infection and poor wound healing
Examples of humoral immunodeficiency disorders (5)
- X-linked (Bruton’s) Agammaglobulinemia
- Hyper IgM syndrome
- Transient hypogammaglobulinemia of infancy
- Common variable immunodeficiency (CVID)
- Selective immunoglobulin deficiency
X-linked (Bruton’s) Agammaglobulinemia
- Absence of all Ig classes
- Pre-B cells in marrow can’t mature
- Due to defect in tyrosine kinase (BTK)
Management of Bruton’s Agammaglobulinemia
- Avoid infection
- antibiotics
- IVIG
Hyper IgM syndrome
- Defect in CD40 or CD40 ligand
- Defective class switching
- Defective memory
- Recurrent infection
Transient hypogammaglobulinemia of infancy
IgG developmentally delayed, but B cells are normal, usually goes away by 2-3
Common Variable Immunodeficiency (CVID)
Low serum levels of all ig, increased susceptibility, B cell to plasma cell transition, treat with IVIG
Selective Ig deficiency
- Deficiency in single Ig class or subclass
- IgA most common
Di George syndrome
Hypoplastic thymus, recurrent infection of intracellular bacteria, fungi, and viruses
-Also pyogenic organisms due to lack of T-cell help for B-cells
Severe Combined immunodeficiency (SCID)
Both humoral and cell mediated immunity are defective, patients susceptible for all infectious agents
Examples of SCID (3)
- X-linked SCID
- Adenosine deaminase (ADA) deficiency
- RAG1 or RAG 2 deficiency
X-linked SCID
Mutated gamma chain of IL-2 receptor, most common SCID, defective T cell, B cell and NK cell development
Adenosine deaminase deficiency
-Deoxyadenosine buildup damages B and T lymphocytes because of all the cell division
RAG1 or2 deficiency
Cannot undergo V(D)J recombonation, no T or B cells
