Session 8 Flashcards
(31 cards)
What is the immunocompromised host?
State in which he immune system is unable to respond appropriately and effectively to infectious microorganism
Due to a defect in one or more components of the immune system e.g B cells, neutrophils, T cells, complement proteins
Why is a host immunocompromised?
Primary immunodeficiency
- congenital
Secondary immunodeficiency
- acquired
- underlying disease/treatment
- get decrease function/production of immune components
- loss or catabolism of immune components
Why suspect immune defieicny?
SPUR S - severe infection P - persistent, don’t respond to meds quick U - unusual site of infection R - recurrent, keeps coming back
What are some warning signs of PID in children?
- four or more ear infections in 1 year
- 2+ months on antibiotics with little effect
- failure to gain weight/ grow normally
- persistent thrush in mouth or fungal skin infection
- need IV antibiotics to clear infection
- 2 or more pneumonia’s in 1 year
What are the warning signs of PID in adults?
- 2+ ear infections in 1 year
- family history (25% chance)
- recurrent viral infections
- chronic diarrhoea and weight loss
- pneumonia ever year for more than 1 year
- deep abscesses of skin/internal organs
What are the limitations of these warning signs of PID?
- lack of population based evidence
- PID patients with deferent defects/presentations
- PID patients with non infectious manifestation
How does onset of PID suggest the type?
Onset before 6 months = T cell/phagocyte deficiency
Onset between 6 months - 5yrs = B cell/antibody or phagocyte deficiency
Onset more than 5 years = B cells/ antibody or SID
How will people with complement deficiency present?
Pyrogenic infections
Meningitis/sepsis/arthritis
Angioedema
How will people with phagocytic defects present?
- Skin/mucous infections
- Deep seated infections
- Invasive fungal infections
How will people with antibody deficiency’s present?
- sinorespiratory infections
- arthropthies
- GI infections
- malignancies
- autoimmunity
How will people with T cell defects present?
- death if not treated
- deep skin tissue and abscesses
- opportunistic infections
How do you manage PIDs?
Supportive
- prophylaxis
- treat infections promptly
- nutritional support for vitamins
Specific
- regular immunoglobulin therapy
- haematopoietic stem cell therapy
Comorbidities
- autoimmunity and malignancies
- organ damages
- avoid non essential exposure to radiation
What causes SID?
- malnutrition
- infection
- liver disease
- lymphoproliferative diseases
- splenectomy: causes are - infarction (e.g sickle cell anaemia), trauma, autoimmune haemolytic disease, infiltration, coeliac disease, congenital
What is the spleens immune role?
- Gets rid of blood borne pathogens
- Antibody production - acute IgM and one term IgG production
- splenic macrophages
How would the asplenic patient Present and whats the management?
Presentation
- increased susceptibility to encapsulated bacteria
- overwhelming post splenectomy infection
Management
- penicillin prophylaxis
- immunisation against encapsulated bacteria
- medic alert bracelet
How will patients with haemoatological malignancy be more prone to infection?
May have chemotherapy induced neutropenia or damage to mucosal barriers.
Treat suspected neutropenic sepsis ASAP
What kind of deficiency’s will viral, fungal and bacterial infections be prevalent in?
Virus and fungi = T cell deficiency
Bacteria and fungi = B cell/granulocyte deficiency
What hepatitis?
Inflammation of the liver
Viruses replicate specifically in hepatocytes and thus cause their destruction
What types if hepatitis are chronic?
B and C
How is bilirubin excreted and how does hepatitis prevent this?
RBC break down in spleen and bilirubin is transported to the liver for coagulation before being excreted as bile.
Hepatitis prevents conjugation in liver.
What does a liver function test detect?
- Bilirubin
- Liver transaminases (ALT) and (AST) excreted in large amounts in hepatocytes if damaged.
- alkaline phosphatase secreted in biliary tract damage
- albumin levels
- test of coagulations as clotting factors are synthesised in liver
Whose at risk of hepatitis B?
- vertical transmission
- sexual contact
- IV drug users
- close household contacts
- healthworkers via needlestick injuries
What are the symptoms of HepB?
Jaundice Fatigue Abdominal pain Anorexia Nausea Vomiting Arthralgia ( joint pain)
How long is the incubation period for acute hepB?
6 wks/6 months
Clear infections within 6 months
Becomes chronic in 10% of cases
