immune deficiency Flashcards
define primary immunodeficiency
Primary immunodeficiencies are disorders in which part of the immune system is either missing or functioning abnormally. In primary immunodeficiency, the defect arises because of a problem with the immune system itself. It is not secondary to other disease processes, toxins or drugs.
what is a sign of immunodeficiency
Repeated, unusual, or difficult-to-treat infections are an important sign of immunodeficiency, which should be considered in anyone who requires multiple courses of antibiotics or is hospitalized for infections.
An individual keeps getting infected with encapsulated bacteria, where is the defect likely to be in the immune system
B cells or complement pathway
An individual keeps getting infected with staphylococci and gram-negative bacteria as well as fungi, where is the defect likely to be in the immune system
non-specific (innate) immunity: phagocytes
what does a defect in complement proteins predispose an individual to
meningitis caused by Neisseria meningitidis.
an individual keeps presenting with fungal, viral, protazoan and bacteria infections where is the defect in their immune system
T cell or macrophages
An individual presents complaining of recurrent attacks of cold sores (herpes simplex) or shingles (herpes varicella zoster) and candida infection. where is the defect likely to be
T cell
Herpesvirus-induced tumours, notably Kaposi sarcoma (human herpesvirus 8 [HHV8]), and non-Hodgkin lymphoma (Epstein-Barr virus [EBV]) are characteristic of dysfunction in which part of the immune system
T cell
Define SCID
severe combined immunodeficiency (SCID), which refers to a group of disorders that affect both T and B cells.
how would you manage SCID
stem cell transplant
describe the inheritance of SCID
Some of these disorders are autosomal inherited and there may be a family history of consanguinity (marriage of related individuals). Other types of SCID are X-linked SCID and there may be a history of early deaths in maternal uncles. The DiGeorge syndrome is caused by a large part of chromosome 22 being translocated to other chromosomes, which is not inherited.
give an example of a polygenic disorder that results in immunodeficiency
Common variable immunodeficiency (CVID), IgA deficiency, and specific antibody deficiency are relatively common polygenic disorders that affect antibody production.
how would you treat primary immunodeficiency
The aim of treatment is to prevent infection. In cases of mild immunodeficiency, such as specific antibody deficiency, prophylactic antibiotics may be adequate. In more severe antibody deficiency, immunoglobulin replacement therapy is required. Administration of immunoglobulin is a type of passive immunotherapy. Antibodies against a wide range of pathogens are needed; therefore Ig pooled from several thousand normal donors is used. Ig replacement can be given intravenously or subcutaneously.
Stem cell transplant in SCID
what conditions are common in phagocyte immunodeficiency
pneumonia, osteomyelitis, skin/mucous membrane infection, liver abscesses
Organisms involved - bacteria (staphylocci, E.coli, salmonella) and fungi (Candida and aspergillus)
what are clues that child has SCID
usually well for first 3 months of ;ife
ipersistent superficial candida
diarrhoea and FTT
