Immunology Flashcards
Features of Wiskott-Aldrich
T cell immune deficiency, Thrombocytopenia, Eczema, X linked
Features of DiGeorge syndrome
Heart, palatal and facial defects, absent thymus hypocalcaemia
Cause of DiGeorge syndrome
Deletion of section of chromosome 22 causing maldevelopment of 5th branchial arch
Features of Duncan syndrome
X-linked lymphoproliferative disease - unable to respond to EBV, either die of the infection or develop secondary lymphoma
Features of ataxia telangiectasia
T cell defects, defect in DNA repair, increased risk of lymphoma, cerebellar ataxia, developmental delay
What is the defect in Bruton agammaglobulinaemia
X linked; abnormal tyrosine kinase gene, which is needed for B cell maturation
Features of selective IgA deficiency
Most common primary immune deficiency; asymptomatic or recurrent ear, sinus, pulmonary infections
What is the defect in chronic granulomatous disease
Neutrophil phagocytosis - failure to produce superoxide after ingestion of microorganisms
What are the features of chronic granulomatous disease?
Recurrent bacterial infections
Poor wound healing
Invasive fungal disease
Granulomas from chronic inflammation
What is the defect in leukocyte adhesion deficiency?
Deficiency of neutrophil surface adhesion molecules, CD18 and CD11b - neutrophils are unable to migrate to sites of infection/inflammation
What are the features of leukocyte adhesion deficiency
Delayed separation of umbilical cord
Delayed wound healing
Chronic skin ulcers
Deep seated infections
What are the features of complement defects
Recurrent bacterial infections
SLE like illness
Recurrent meningococcal infections
What is the defect in hereditary angioedema?
Deficiency of C1 inhibitor leads to spontaneous activation of classic complement pathway and kinin-releasing syndrome
What is the defect in Duncan disease?
defect of SLAM associated protein which is involved in T cell stimulation
Which cells have defects in X-linked lymphoproliferative disease?
CD8+, NK cell and T cells
What are the clinical features of X-linked lymphoproliferative disease?
Fulminant mono
Lymphoma
Dysgammaglobulinaemia
Aplastic anaemia
What are the features of IPEX?
Onset in infancy
Immunodysregulatory syndrome with a triad of:
○ Enteritis
○ Endocrinopathy
○ Dermatitis
Can also have cytopenia, glomerulonephritis, hepatitis
Susceptible to bacteria, viral and fungal infections
High rate of mortality - most die before 2 years without HSCT
What is the defect in Chediak-Higashi?
Lysosome-related organelle disorder
What are the clinical features of Chediak-Higashi?
Immunodeficiency
Neurological: weakness, ataxia, peripheral neuropathy, progressive neurodegeneration
Hypopigmentation: oculocutaneous albinism
Accelerated phase with haemophagocytosis, lymphocyte and monocyte infiltration of tissues, often fatal
Who is more likely to get SCID?
Males affected more than females because X-linked SCID caused by common gamma chain deficiency is the most common form; the remaining forms are autosomal recessive
When does classical SCID present?
6-7 months
What are the clinical features of classical SCID?
Respiratory infections Diarrhoea and faltering growth Oral thrush and perineal candidiasis BCG complications Disseminated viral infections Skin rash Absent lymphoid tissues
What is Omenn syndrome?
A kind of SCID - Exaggerated inflammatory response caused by emergence of oligoclonal T cell populations, often autoreactive. Clonally expanded T cells then infiltrate tissues
What are the clinical features of Omenn syndrome?
Skin - erythroderma, thickened and leathery skin, hair loss
Gut - chronic diarrhoea, protein loss leading to oedema
Reticuloendothelial system - lymphadenopathy, hepatosplenomegaly
What is the defect in Omenn syndrome?
Most frequently occurs with RAG1 or RAG2 deficiency, in which B cells are absent
What is maternofetal engraftment in SCID?
Patients with SCID don’t have functional T cells so can’t reject foreign lymphocytes
Maternal T lymphocytes that cross the placenta engraft in the infant, mediating a graft vs host process
Presents as morbiliform erythroderma or papular dermatitis
What is the common defect in Wiskott-Aldrich?
deficiency in WASP protein which leads to global aberration in innate and adaptive immunity
What are the features of ataxia telangiectasia?
Defect in DNA repair T-cell defects Increased risk of lymphoma Cerebellar ataxia Ocular telangiectasia Developmental delay
What is CVID?
B-cell deficiency
High risk of autoimmune disorders and malignancy
What are the clinical features of CVID?
Later onset than X-linked agammaglobulinaemia
Recurrent sinopulmonary infections with reduction in 2 or more Ig isotypes and impaired vaccine responses, usually >2 years
Clinically heterogeneous
What will be the blood results in CVID?
Reduction in at least two of IgG, IgA and IgM
Impaired functional antibody response to vaccines
what is the defect in hyper IgM syndrome?
• CD40L deficiency leads to lack of class switching, then therefore cellular and humoral immunity
What is the triad of Hyper IgE syndrome?
High IgE and eosinophilia
Eczema
Recurrent skin and pulmonary infections
What is Job syndrome?
AD form of Hyper IgE caused by STAT3 mutation
How does hyper IgE syndrome present?
Pustular rash in newborn period, which can evolve
Cutaneous cold abscesses, lacking signs of inflammation
Otitis media, sinusitis, pyogenic pneumonia
Fungal infections
What are the typical facies in Hyper IgE?
Prominent forehead and chin Deep set eyes Bulbous nose Coarse facial features Facial asymmetry High palate
What are some associated features of hyper IgE?
Scoliosis, midline anomalies, craniosynostosis, vascular abnormalities
What are the features of Schwachman-Diamond?
Pancreatic exocrine insufficiency
Skeletal abnormalities
Recurrent infection of lungs, bones and skin
Most have neutropenia
Up to 25% have pancytopenia
Risks of myelodysplasia and leukaemia are increased
What are the features of cyclical neutropenia?
Recurrent neutropenia for 3-6 days over a 21 day cycle (some variation)
Autosomal dominant
May cause stomatitis, oral ulcers or bacterial infections
