Allergy/Immunology 3 Flashcards
What is an immunodeficiency? (4)
- A failing of one or more of the body’s defensive mechanisms resulting in morbidity or mortality.
- Any part of the immune system can be deficient- cells, proteins, signaling mechanisms…….
- The body is susceptible to infection by organisms that meet with little or no resistance.
- Severity is variable.
Immunologic response (3)
- Principle underlying pediatric immunizations
- Immunodeficiency
a. >140 inherited immunodeficiency disorders identified
b. Worldwide pandemic of HIV infection- heightened awareness of immunology and immune deficiency disorder - Can be divided into secondary and primary immunodeficiency
a. HIV can cause a secondary immunodeficiency (ex: viral infection causing neutropenia)
Distribution of primary immunodeficiency (5)
- B cell: 50%
- T cell: 10%
- T & B cell: 20%
- Phagocyte: 18%
- Complement: 2%
Secondary immunodeficiency (5)
- Infection (HIV)
- Renal failure, or protein losing enteropathy (malnutrition)
- Leukemia or Lymphoma
- Certain Drug Therapies
- Others
Common B-cell immunodeficiencies (4)
a. Selective IgA deficiency (1:500)
b. IgG2 subclass / Selective antibody deficiency
c. Transient hypogammaglobulinemia of infancy
d. DiGeorge anomaly
Jeffery Modell Criteria (10)
MUST KNOW ALL OF THESE; two or more requires a work-up
- Four or more new ear infections within 1 year.
- Two or more serious sinus infections within 1 year.
- Two or more months on antibiotics with little effect.
- Two or more pneumonias within 1 year.
- Failure of an infant to gain weight or grow normally.
- Recurrent, deep skin or organ abscesses.
- Persistent thrush in mouth or fungal infection on skin.
- Need for intravenous antibiotics to clear infections.
- Two or more deep-seated infections including septicemia.
- A family history of PI.
Clinical Manifestations that Raise Suspicion of Primary Immune Deficiency (4)
- Warts (human papilloma virus recurrent infections)
a. WHIM syndrome (warts, hypogammaglobulinemia, infections, myelokathexis)
b. Epidermodysplasia verruciformis
c. DOCK8 deficiency (hyper-IgE syndrome)
d. GATA2 deficiency (Mono MAC syndrome, DCML deficiency)
e. IRF8 deficiency
f. Combined immunodeficiencies - Ataxia
a. Ataxia-telangiectasia
i. When you look at the whites of the eye there are swirly vessels in them
b. Ataxia-telangiectasia like disease (ATLD) ! PNP deficiency Microcephaly
c. Cernunnos deficiency
d. Ligase IV deficiency
e. Ligase I deficiency
f. Nijmegen breakage syndrome
g. Dyskeratosis congenita - Deafness
a. Reticular dysgenesis
b. ADA deficiency - Partial albinism
a. Immunodeficiencies with immune dysregulation and hypopigmentation
i. Griscelli syndrome
ii. Chediak-Higashi syndrome
iii. Hermansky-Pudlak syndrome
Autoimmunity (2)
- Occurs when the immune system begins attacking self components of the body aberrantly
- Autoimmune diseases include multiple sclerosis, rheumatoid arthritis, lupus and type I diabetes
Alloimmunity (2)
- Immune system reacts against antigens on tissues of other members of the same species
a. Neonatal diseases where maternal immune system becomes sensitized against antigens expressed by fetus
b. Transplant rejection and transfusion reactions when immune system of recipient of organ transplant or blood transfusion reacts against antigens on donor cells - Fetus affected by maternal antibodies
a. Rh and ABO alloimmunization
b. Graves disease: Maternal antibody against TSH receptor causes neonatal hyperthyroidism
Disorders of immune system (2)
- Immune deficiencies
a. Defects of the Adaptive immune system
i. T lymphocytes (cellular) immune function
ii. B lymphocytes (humoral) immune function - Defects of the Innate immune system
a. Considered as group
i. Primarily cellular abnormalities
ii. Soluble protein defects
Clinical presentations of immune deficiency (14)
- Cellular immune defect
- Humoral immune defect
- Neutrophil defect
- Interferon gamma/ interleukin 12 pathways defect
- Complement defect
- Early component
- Terminal component
- Recurrent opportunistic infection
- Recurrent sinopulmonary infection with encapsulated bacteria
- Recurrent bacterial and fungal infections involving the skin and organs
- Recurrent atypical mycobacterial
- Salmonella infections
- Recurrent sinopulmonary infections
- Recurrent Neisseria infections
Immunodeficiency lab values (7)
- Low Lymphocyte count
- Low neutrophil count
- Low leukocyte count
- IgA deficiency is probably most common
- Cellular immunity tends to be looked at first
- Humoral immunity: Quantitate immune globulins
- Do total neutrophil count
Clinical Presentation of Patient with T cell dysfunction (7)
Infections with intracellular “opportunistic” microorganisms
a. Viruses (HSV, V-Z, CMV, EBV)
b. Protozoa (Cryptosporidium, toxoplasma)
c. Mycobacteria
d. Fungal (Candida, Pneumocystis carinii)
e. Bacteria, gram negative enteric (T-cell)
f. Bacteria, polysaccharide encapsulated (B-cell)
g. DiGeorge will present with opportunistic infections
DiGeorge Syndrome (6)
- Congenital thymic hypoplasia
- Dysmorphogenesis of 3rd and 4th pharyngeal pouches
- Hypoplasia of thymus
- Other issues: Congenital heart disease and Hypoparathyroidism
- Deletion of several genes on chromosome 22
* Cardiac diseases are associated with chromosome 22 - Syndrome – variable
a. Hypoplasia versus aplasia of parathyroid and thymus
i. Thymic hypoplasia can lead to cellular immunodeficiency
b. B cell numbers normal
i. antibody response can be intact if sufficient T-cell function for T-cell help
c. If thymic hypoplasia partial, few or no life threatening infections
Antibody deficiency (3)
- Occurs later due to maternal transfer of antibodies
- 3-6 month lag time before they present
- Child will usually not present until after 6months due to maternal protection
a. No tonsils