Ch 6: Immunopathies (Part 5 - Immunodeficiency syndromes) Flashcards
(50 cards)
Name the 2 types of immunodeficiency syndrome you can have.
Primary = genetic
Secondary = acquired (ex: HIV)
In general, what infectious diseases can you get with B-cell deficiencies?
Pyogenic bacterial infections
Enteric bacterial and viral infections
In general, what infectious diseases can you get with T-cell deficiencies?
Viral and other intracellular microbial infections (eg. pneumocystis jiroveci, other fungi, nontuberculous mycobacteria)
Some cancers (eg. EBV associated lymphomas, skin CA)
In general, what infectious diseases can you get with Innate immune deficiencies?
Variable - pyogenic, bacterial, anf viral infections
Name some innate immunodeficiencies affecting leukocytes.
Chediak Higashi syndrome
Chronic Granulomatous disease
What is Chediak Higashi syndrome?
Autosomal recessive
Failure of phagolysosomal fusion
Increased bacterial infection
Fatal w/o stem cell transplant
How can you detect Chediak Higashi histologically?
You can observe the failure of fusion on peripheral smear
Giant granules seen
Defects in melanocytes or grey hair streaks
What is chronic granulomatous disease?
Common mechanism = failure of superoxide production within phagocytes
Accumulation of macrophages “walls off” infection
Name some innate immunodeficiencies affecting complement.
Membrane attach complex deficiency
Hereditary angioedema? (not really, but…)
What is membrane attack complex deficiency?
Without final MAC, lysis of microbial membrane can’t occur
Happens when any of C5, 6, 7, 8, 9 are affected
Nisseria infections are common
Results in meningitis
What is hereditary angioedema?
Autosomal dominant
Deficiency of C1 inhibitor
Complement system goes nuts and you see increased in complement
Episodes of angioedema
What are some symptoms of hereditary angioedema?
Swelling of lips Swelling of airway Huge mucosal folds - intestine Swelling of genitals Dysuria Cutaneous edema
Name some adaptive immunodeficiencies affecting lymphocyte maturation.
Severe Combines Immunodeficiency (SCID)
Digeorge syndrome
X-linked Agammaglobulinemia
What is SCID? What are the 2 forms of inheritance?
Deficiency in both B cell and T cell lineages due to defect in T-cell function
2 forms = X-linked and Autosomal recessive
Describe the X-linked version of SCID.
Affects MALES
Mutations in IL receptors
T-cell reduced in number
B-cells present but unable to make Ab without T-cell help
Describe the autosomal recessive version of SCID.
Adenosine deaminase deficiency = MOST COMMON
Accumulation of toxic purine metabolites
Blocks T-cell formation
Some B-cell influence, but lacks helper T-cells to activate humoral response
How can you treat SCID?
Stem cell transplantation
Gene therapy
What is DiGeorge syndrome?
Primary deficiency of T-cell due to failure of dev of pharyngeal pouches 3 and 4:
Affects thymus, parathyroid, heart, and great vessels
How is DiGeorge inherited? What chromosome is associated with the disease?
May be inherited in sporadic and familial pattern
Many cases are 22q11 deletions
What are some physical manifestations of DiGeorge syndrome?
Facial and palatal abnormalities (micrognatia)
Cardiac abnormalities (tetralogy of fallout, trunks arteriosus)
Tetany - (not having enough calcium b/c parathyroid affected)
Immune deficiency
T cell def.
Humoral def if T-cell function if poor enough
What is X-link agammaglobulinemia?
Defect in Bruton tyrosine kinase (BTK) gene on X-chromosome - inability of pre-B cells to mature
Risk for infection increases after maternal abs wane, may even present in late childhood
What diseases can you get with agammaglobulinemia?
Encapsulated bacteria (streptococcus, pseudomonas, homophilus influenza type B)
Viruses
Protozoa (Giardia lamblia)
Name some adaptive immunodeficiencies affecting lymphocyte activation/function.
Hyper IgM syndrome
Common Variable Immunodeficiency (CVID)
IgA deficiency
What is Hyper IgM syndrome?
Encapsulated bacterial infections predominate due to lack of opsonizing antibodies
CD40/40L mutations Interferes with T-cell helping B-cells to class switch
Increase IgM levels, but lower levels of other classes
