Secondary Immune Deficiencies Flashcards
The tissue of the spleen can be divided into 2 sub groups, the red pulp and the white pulp. What is the function of each of these areas of the spleen?
What are some immune abnormalities seen in asplenic patients?
Which organisms are asplenic individuals most at risk for being infected by?
Encapsulated pathogens
What are some essentials in caring for an asplenic patient?
Fever - normal person would give NSAIDs or other fever reducers but in asplenic patient must think infection
Vaccinations - esp against pneumococcous, haemophilus, and meningococcous
What can cause impaired spleen function?
What is the function of neutrophils?
Phagocytosis and host defense against bacteria and fungi
What is febrile neutropenia?
External factor (i.e. systemic steroid use) causes reduced # of neutrophils leading to immune deficiency and increased risk of febrile illness
If a patient has infection with pseudomonas, what should you instantly think of?
Febrile Neutropenia
What are patients with neutropenia given as a treatment?
Granulocyte colony stimulating factor
Rituximab is a medication used to treat auto immune diseases and cancer. What is its mechanism of action?
It is an antibody against the CD20 ligand on the surface of b cells –> leads to b cell destruction via several mechanisms:
- Complement mediate cytotoxicity
- Opsonization and phagocytosis by macrophages
- Direct lysis via NK cells
Due to its mechanism of action, how can rituximab cause secondary immune deficiency?
Attacks b cells, takes 6 - 24 months to recover, can lead to decreased immune function (hypogammaglobulinemia) and increased infections
How is symptomatic hypogammaglobulinemia secondary to rituximab use treated?
Describe the mechanism of action of corticosteriods and how they result in anti-inflammatory effects as well as immune suppression?
Glucocorticoid –> diffuse across membrane –> bind to receptor in cytosol –> bound by HSP to stabilize complex –> transported to nucleus through nuclear pore via cytoskeleton and dynein motor transport –> Dimerize in nucleus with another GCR receptor complex –> bind to GCR response element on DNA –> immediately will initiate transcription of mRNA that encodes Annexin A1 and will long term suppress transcription of COX-2 and inflammatory cytokine genes –> Annexin A1 then inhibits COX-2 and PLA2 resulting in decreased inflammatory response and it also leads to decreased ability of neutrophils to enter tissue resulting in immune suppression and it also inhibits the respiratory burst in neutrophils thus decreasing their function.
True/False: If a patient is on GCRs, the best time to vaccinate them is before they start GCR use.
True
What types of infections do you need to be concerned about in patients on long term use of systemic GCRs
C
C
C
A
