immunology Flashcards
what does SPUR stand for in immune deficiency?
- Serious infections (unresponsive to oral antibiotics)
- Persistent infections (early structural damage, chronic infections)
- Unusual infections (organisms and sites)
- Recurrent infections (1 or 2 major and recurrent minor infections in a year
what features might suggest immune deficiency? (apart from SPUR)
- weight loss or failure to thrive
- severe skin rash
- chronic diarrhoea
- mouth ulceration
- unusual autoimmune disease
- lymphoproliferative disorders
- cancer
- family history
what are primary immunodeficiency disorders?
- respiratory diseases are the main and initial manifestation in most cases and the most common complication
- pulmonary complications cause significant morbidity and mortality in patients with PIDs
- early diagnosis and appropriate treatment can prevent or at least slow the development of respiratory complications
- e.g. sinusitis, ottis media, laryngeal angioedema, malignancies, interstitial lung disease, pneumonia, bronchitis, bronchiectasis.
what are secondary immunodeficiency disorders?
- this is the most common type, is often subtle and often involves more than one component of the immune system
what is the most frequent primary immunodeficiency associated with sinusitis and ottis media?
- Primary antibody deficiency (PAD)
- less common = selective IgA deficiency, common variable immunodeficiency, specific antibody deficiency, X-linked agammaglobulinemia
what primary immunodeficiency disorder should be considered in patients with laryngeal angioedema?
- complement system disorders
- angioedema is characterised by local swelling that is generally asymmetrical owing to increased vascular permeability with leakage of plasma (not allergic but can be life threatening)
what primary immunodeficiency might people with pneumonia have?
- primary antibody deficiency (PAD)
- complement system disorders
- congenital phagocytosis deficiency
- combined immunodeficiencies
Describe congenital neutropenias.
- congenital neutropenias (kostmann syndrome)
- neutropenia = abnormally low concentration of neutrophils in the blood.
- rare genetic disorder, SCN type 1 is the commonest form and is inherited in an autosomal dominant manner
- this leads to recurrent bacterial/ fungal infections within 2 weeks of birth
- treated with recombinant G-CSF
what is leukocyte adhesion deficiency?
- very rare autosomal recessive primary immunodeficiency
- caused by genetic defect in CD18 integrin gene
- results in failure of neutrophil adhesion and migration
- clinical picture marked by leucocytosis and localised bacterial infections.
- treatment is hematopoietic stem cell transplant and prophylactic antibiotics
- results in recurrent bacterial and fungal infections in deep tissues and a very high neutrophil count.
what Is chronic granulomatous disease?
- deficiency of the intracellular killing mechanism of phagocytes - absent respiratory burst
- commonest form is a deficiency in a gene that makes a component of the NADPH oxidase complex (X-linked)
- inability to generate oxygen/nitrogen free radicals.
- impaired killing of intracellular micro-organisms.
- clinical presentations; recurrent deep bacterial infections, failure to thrive, lymphadenopathy and hepatosplenomegaly (enlargement of spleen and liver), granuloma formation.
what is the treatment for phagocyte deficiencies?
-immunoglobulin reblacement theraoy
-aggressive management of infection (oral/ IV antibiotics and anti-fungals, drainage of abscesses)
- haematopoietic stem cell treatment
-gene therapy
SCN - recombinant G-CSF
what are important PIDs associated with respiratory complications in children?
- transient hypogammaglobulinemia of infancy
- severe combined immunodeficiency’s
- X-linked agammaglobulinemia.
- congenital neutropenia
what is transient hypogammaglobulinaemia?
when the foetus fail to produce its own IgG after using sIgA from breast milk.
what is severe combined immunodeficiency (SCID)?
- failure of production of lymphocytes
- clinical presentation; unwell by 3 months of age, persistent diarrhoea, failure to thrive, infections of all types, unusual skin disease and family history of early infant death.
- over 20 possible causes identified
- commonest form is X-linked (mutation of IL-2 receptor)
- treatment; avoid infections and aggressively treat them, antibody replacement therapy, stem cell transplant from HLA identical sibling if possible, stem cell transplant.
what is bruntons X-linked hypogammaglobulinaemia?
- no circulating B cells
- no plasma cells
- no circulating antibodies after 6 months
- Severe combined immunodeficiency
