Chapter 6- Immunodeficiency Syndromes Flashcards
When are primary (congenital) syndromes detected?
6 months - 2 years of life
What defects occur in primary congenital syndromes?
defect in innate immunity and defect in adaptive immunity
Defect in innate immune system in primary congenital syndromes
affect leukocyte functions or complement system
Defect in adaptive immunity in primary congenital syndromes
abnormalities in lymphocyte maturation or activation
Immunodeficiency Syndromes
SCID
What parts of the immune system are defective in SCID?
humoral and cell-mediated immune response
What do infants with SCID present with?
prominent thrush (oral fungi)
extensive diaper rash
failure to thrive
What infections are patients with SCID susceptible to? (5)
candida albicans Pneumocystis jiroveci Pseudomonas CMV varicella
When does death occur with SCID
in the first year without HSC (BMT) transplantation
Genetics of SCID
X linked or autosomal recessive
What occurs in X-linked Agammaglobulinemia
failure of B-cell precursors to develop into B cells
Characteristics of X-linked Agammaglobulinemia (4)
B cells are absent
All serum Igs are depressed
Plasma cells are absent
T cell-mediated reactions are normals
When does X-linked Agammaglobulinemia become apparent?
6 months which is when maternal Igs are depleted
What infections is a patient with X-linked Agammaglobulinemia susceptible to?
Recurrent bacterial infections of respiratory tract
Viruses in bloodstream or mucosal secretions
Giardia lamblia
Bacterial infections of respiratory tract with X-linked Agammaglobulinemia
haemophilus influenczae
streptococcus pneumoniae
staphylococcus aureus
Viruses in bloodstream or muscosal secretion in X-linked Agammaglobulinemia
enteroviruses- echovirus, poliovirus, coxsachievirus
What causes X-linked Agammaglobulinemia
breakdown of self tolerance and chronic infections
Treatment for X-linked Agammaglobulinemia
Replacement therapy with immunoglobulins (IgG)
What causes DiGeorge Symdrome
Failure of development of the 3rd and 4th pharyngeal pouches
What cells are deficient in DiGeoge Syndrome?
T cells
Thymic hypoplasia
What do the 3rd and 4th pharyngeal pouches give rise to
thymus, parathyroids, C cells of thyroid, ultimobrachial body
Thymus in DiGeorge Syndrome
Loss of T cell-mediated immunity
Poor defense against fungal and viral infections
Parathyroids in DiGeorge Syndrome
Hypocalcemia causing tetany
Ultimobranchial body in DiGeorge Syndrome
Congenital defects of the heart and great vessels
Genetics of DiGeorge Syndrome
22q11 deletion syndrome
Characteristics of Hyper-IgM Syndrome
elevated IgM
can’t produce IgG, IgA, IgE
Cause of Hyper-IgM Syndrome
defect in ability of helper T cells to deliver activating signals to B cells and macrophages
Clinical presentation for Hyper-IgM Syndrome
recurrent pyogenic infections
Patients with CD40L mutations in Hyper-IgM Syndrome
susceptible to Pneumocystic jiroveci pneumonia
What occur if IgM antibodies react with blood cells?
autoimmune hemolytic anemia
thrombocytopenia
neutropenia
What is Common Variable Immunodeficiency?
group of disorders with hypogammaglobulinemia (low Igs)
Characteristics of Common Variable Immunodeficiency
have normal/near normal numbers of B cells
but can’t differentiate into plasma cells
Difference between Common Variable Immunodeficiency and X-linked Agammaglobulinemia (3)
CVI has normal B cells, equal in male and female, and occurs in childhood or adolescence
Characteristics of Isolated IgA Deficiency?
Extremely low levels of both serum and secretory IgA
Symptomatic patient with Isolated IgA Deficiency
recurrent sinopulmonary infections and diarrhea
high frequency of respiratory tract allergy
autoimmune diseases
Treatment for Isolated IgA Deficiency
transfuse IgA containing blood
What occurs in IgA transfusion if patient has severe IgA deficiency?
IgA behaves like a foreign molecule and the patient can develop severe/fatal anaphylactic shock
Systemic Immunodeficiencies
Wiskott-Aldrich syndrome
Ataxia telangiectasia
Wiskott-Aldrich Genetics
X-linked
Characteristics of Wiskott-Aldrich syndrome
thrombocytopenia, eczema, and recurrent infections leading to early death
Treatment for Wiskott-Aldrich
HSC transplantation
Ataxia telangiectasia Genetics
autosomal-recessive
Characteristics of Ataxia telangiectasia
abnormal gait vascular malformations neurologic deficits increased incidence of tumors immunodeficiency
Secondary (Acquired) Immunodeficiency (8)
Cancer Diabetes Complications of Cancer AIDS Malnutrition Irradiation Immunosuppressive therapy Chemo
Irradiation and Chemo mechanism treatments for cancer
decreased bone marrow precursors for all leukocytes
Malnutrition (protein-calorie) malnutrition mechanism
metabolic derangements inhibit lymphocyte maturation and function
Spleen Removal mechanism
decreased phagocytosis of microbes
