What is an “immunocompromised” host?
state in which the immune system is unable to respond apprpriotely and effectively to infectious microorganisms.
Due to defect in one or more components of the immune system...
what r the reasons why people become “immunocompromised”? (2)
Primary immunodeficiency "congential"
Due to intrinsic gene defect (~275 genes)
• Missing protein
• Missing cell
• Non-functional components
Seocndary immunodeficiency "acquired"
Due to an underlying disease/treatment
• ↓ Production/function of immune components
• ↑ Loss or catabolism of immune components
Factors affecting the innate immune system :
resons why ppl can get immunocompromised?
Hickman line: An artificial plastic line inserted through the skin and directly into the vascular system. This is a source of direct entry for micro-organisms. In addition it provides an artificial surface within the body for organisms to attach to.
Mucositis: This allows for breaks in the mucosal barrier.
Loose stool: GI tract is affected in a similar way to the mouth. The normal mucosal lining will be eroded, altering the motility of the bowel (sometimes with loose stools) and a site for organisms to enter.
Low neutrophil count: Chemotherapy acts on dividing cells within the bone marrow. It affects all cell lines. This includes all the WBC of which the neutrophils are important as part of the first line of defence.
why is chemotherapy dangerous and how can it lead to immunocompromisation?
chemotherapy which is designed to target T-cells.
what triggers the release of CRP and what is it's role in the innate immune response?
Microbial toxins – e.g. endotoxin – triggers the production of cytokines by monocytes and macrophages. These in turn circulate in the blood to the liver where they stimulate the production of the acute phase proteins.
what causes chicken pox?
describe the pattern of infection of varicella zoster?
has a latent pattern of infection.
Following the acute chicken pox infection, Varicella-zoster virus enters ‘ganglia’ where it becomes dormant, or enters a ‘latent phase’.
It is not cleared but is kept in check by T-cell and usually does not cause any further problem.
However, in some situations it can REACTIVATE
Viral particles originating in the dorsal root ganglion neuron travel along the nerve to the sensory terminals in the skin.
The rash begins when the virus escapes the nerve terminals and invades the skin.
This is called SHINGLES
what is shiingles?
How do you make the diagnosis?
Shingles can occur in healthy individuals. It is usually associated with aging (which might be linked to reduced T cell responses). It is uncommon in young adults who have normal immunity.
The clinical picture is usually diagnostic. It is possible to take some fluid from the rash. The rash normally has vesicles – fluid-containing papules on the skin. Virus can be detected in the fluid using PCR.
what r the type of infections that suggest an immunodeficiency?
– S severe>> life threatening!
– P persistent >> infections persist despite using the normal recommended treatment
– U unusual>> ur looking at site and the micro organism
– R recurrent >>microorganism keeps coming back!
what r the most important PID's?
what r the 4 classification groups that they are put into?
1) antibody deficiency
2) Combined T & B cell.
3) Phagocytic defects
what is the most common PID related to anitbody deficiency?
Common variable immunodeficiency! (CVID)
alaa he said u have to know this
what is the most common PID related to Phagocytic deficiency?
Chronic granulamotous disease & severe congential neutropenia
they have the neutrophil but lack the machinary that kills!
what factors will tell u the type of immunodeficiency the patient has?
- the age of onset
- type of microbes and its sites
if a peroson has an immune defect of complement deficiency type, what type of infections r included and microbes associated?
- Pyogenic infections (C3)
- Meningitis /Sepsis/Arthritis (C5-C9)
- Angioedema (C1- inhibitor)
neisesseria, hemophilus influenza, streptecocci,
if a peroson has an immune defect of antibody deficiency type, what type of infections r included and microbes associated (bacteria, virus, fungi, protazoa) ?
most likely associated wiht upper tract infections!
- Sinorespiratory infections
- GI infections
enterovirus, Giardia , strep and staph
(they love getting into bodies)
if a peroson has an immune defect of phagocytic defect type, what type of infections r included and microbes associated (bacteria, virus, fungi, protazoa) ?
- • Skin/mucous infections
- • Deep seated infections
- • Invasive fungal infection (aspergillosis)
Phagocytes ate "jill"
Staph Aureus, pseudomonas aureginosa, non TB mycobacteria, candida and asperilligus!
if a peroson has an immune defect of T cell deficiency type, what type of infections r included and microbes associated (bacteria, virus, fungi, protazoa) ?
develops in all kind of infections, cuz if theres no T cells, there no b cells!
- Death if not treated
- Failure to thrive
- Deep skin and tissue
what type of immune defect is associated with upper respiratory tract infections? what other infections r common in this type
what type of immiune defect is associated with EARLY ONSET?.
T cell and phagocytic defects!
somone developed a fungal, viral, and bacteria infection
what immune component is the most likely defect ?
Remmeber it occurs in all types!
why did the kid not develop anything in th last 6 months?
bc he was protected by maternal immunity,
meaning during the 3rd trimester of pregnancy, our mum gave us maternal antibodies, so anthings she was exposed to, all the anitbodies we have em
which disease has no B cells or prevents the maturation of B cells?
mostly boys gets em cus its X-linked
what r these mostly common findings of?
Chronic Granulamotaous disease!
Management of primary immunodeficiency diseases ?
What is the role of CRP in the innate immune response?
CRP acts as an opsonin.
An opsonin binds to the microbial surface leading to enhanced attachment of phagocytes and clearance of microbes.
Where does Aspergillus normally reside?
Aspergillus can be found in dust in buildings.
In addition to Aspergillus, name one other opportunistic fungus that commonly occurs in both normal hosts and immunocompromised hosts?
Candida albicans. This causes ‘Thrush’.
Candida is the only fungus that is part of the normal body flora. It is considered a yeast. It causes infection when the normal flora are eliminated, for example, after antibiotic use, allowing the Candida to overgrow.
What infection does Varicella-zoster cause?
What family of viruses does varicella-zoster belong to?
How does this fit into the classification you were given
Varicella-zoster belongs to the Herpes viruses.
These are double-stranded DNA viruses and have an envelope.