Primary Immunodeficiency Flashcards
Neutrophil disorder
Chronic granulomatomous disease
Chediak-higashi syndrome
Leukocyte adhesion deficiency
B-cell disorders
IgAdeficiency
Bruton’s congential agammaglobinemia
Common variable immunodeficiency
T cell disorders
DiGeorge
- microdeletion
- increased risk or viral and fungal infections
Combined B and T cell disorders
Severe combined immunodeficiency Ataxic telangectasia (autosomal recessive, 10% risk of malignancy, lymphoma or leukaemia and non-lymphoid tumours, recurrent chest infections) Wisconsin-Aldrich (X linked recessive) WASP gene mutation, recurrent bacterial infections, eczema and thrombocytopenia with low IgG
Chronic granulomatous disease
Neutrophil disorder
Lack of NADPH oxidase reduces ability of phagocytes to produce ROS
Recurrent pneumonia’s and abscesses particularly due to catalase positive bacteria (eg staph aureus) and fungi
- negative nitroblue-tetrazolium test
- abnormal dihyrorhidamine flow cytometry test
Chediak- Higashi syndrome
Neutrophil disorder
Microtubule polymerisation defect -> reduction in phagocytosis
‘Partial albinism’ and peripheral neuropathy
Recurrent bacterial infections
Giant granules in neutrophils and platelets
Leukocyte adhesion deficiency
Neutrophil disorder
Defect of LFA-1 (CD18) integrin on neutrophils
Recurrent bacterial infections
Delay in umbilical cord sloughing
Absence of neutrophils/pus at sites of infection
Common variable immunodeficiency
B cell disorders
Varying causes
Hypogammaglobulinemia is seen
May predispose to autoimmune disorders and lymphoma
Bruton’s (x-linked) congential deficiency
Defect in Bruton’s tyrosine kinase (btk) gene that leads to a severe block in B cell development
X linked recessive
Recurrent bacterial infections
Absence of B cells with reduced immunoglobulins of all classes
Selective immunoglobulin A deficiency
Maturation defect in B cells
Most common primary antibody deficiency
Recurrent sinus and resp infections
Associated: coeliac disease and may cause false negative coeliac Ab screen
Severe reactions to blood transfusions may occur- anti IgA abs-> anaphylaxis
DiGeorge syndrome
T cell disorder
22q11.2 deletion
Failure to develop 3rd and 4th pharyngeal pouches
Commonly: CHD, learning difficulties, hypocalcemia, recurrent viral/fungal infections, cleft palate
Severe combined immunodeficiency
Many causes
Commonly X linked due to defect in common gamma chain, a protein used in receptor for IL-2 and other interleukins.
Recurrent infections
Reduced T cell receptor excision circles
Stem cell transplant may be useful
Ataxic telangectasia
Combined B and T cell disorder
Defect in DNA repair enzymes
Autosomal recessive
Features: cerebellar ataxia, telangectasia, recurrent chest infections, 10% risk of malignancy (lymphoma, leukaemia)
Wiskott-Aldrich syndrome
Combined B and T disorder
Defect in WASP gene
X liked recessive
Recurrent bacterial infections, eczema, thrombocytopenia.
Low IgM levels
Increased risk AI and malignancy