Immunology Flashcards
Signs to ?immunodeficiency
Severe, recurrent or invasive infections
Severe, recurrent or disproportionate inflammation
Unusual site/organism of infection
Unexplained lymphoproliferation
What is SCID
Severe combined immunodeficiency
Group of inherited genetic disorders characterised by a deficiency in lymphocytes
T cells are absent in most forms, B and NK vary
X linked is most common = boys = t neg, B +
Lymphocyte count of <2 in an infant <6 months is what until proven otherwise
SCID
? up to 1 yr really
SCID symptoms
Severe, recurrent infection Failure to thrive Chronic diarrhoea ?absent lymph ?erythematous rash
Which vaccines are CI in SCID kids
Live:
1) BCG
2) rotavirus
3) polio
4) VZV (chickenpox)
5) MMR
6) yellow fever
7) LAIV
How is SCID diagnosed
- Lymphocyte phenotyping, flow cytometry
- Lymphopenia
- May see eosinophelia
- Absent thymic shadow on CXR
How is SCID managed
- Gene therapy, BMT before infection
- prophylactic antifungal, abx, antiviral, igg
- No live vaccine
- No breast feeding (CMV)
Characteristic presentation of an antibody deficiency and give eg
Recurrent 1) otitis media/sinusitis 2) conjunctivitis 3) pneumonias tend to present when maternal igG wanes (6-9m) XLA (brutons)
What is hyper igM syndrome
Raised or normal igM, deficient igG,A,E because inability for B cells to class switch eg secondary to T C40L abnormality (X linked)
Tx of antibody deficiency
Prophylactic abx
replace igG
How is primary antibody deficiency diagnosed
- Serum igG,A,M + repeat
- FBC to look for wider lymphopenia (SCID), anaemia, thrombocytopenia and neutropenia
- Flow cytometry and genetic testing
How would an absolute neutrophil deficit present?
Mouth ulcers
Stomatitis
Recurrent fever
Neutropenic sepsis
Causes and tx of absolute neutrophil deficiency
SCN
Cyclical
Secondary eg to chemo
Treat: GCSF ?AML
Cause, presentation + tx of neutrophil chemotaxis defect
Leukocyte adhesion deficiency (Cd18) No pus at site of infection Skin infection, perianal fistula Delayed umbilical cord detachment Enlarged lymph node tx: stem cell transplant
How do chronic granulomatous diseases present
Early onset deep seated catalase + infections (staph, Aspergillus, Norcardia, Serratia)
IBD like disease, perianal abscess
Tx of CGDs
AlloBMT, gene therapy
Describe normal complement pathway
Add pic + MAC
Deficiency in which part of complement increases risk of nicerria meningitidis
C5b-9
What is CVID
Common variable immune deficiency is a hypogammoglobulinaemia of unknown genetic causes especially in adulthood
Can have recurrent infections, autoimmunity and other manifestations
Tx: IgG replace, rarely alloBMT
What infections do PPIs give rise to
C diff, enterobacter, norovirus
Which infections do anticholinergics give rise to
Dental, UTi
Which infections does chemo give rise to
Neutropenia -> fungal and extracell bac eg E coli, staph aureus
What is rituximab, indications
Anti Cd20 antibody acting on peripheral B cells for lymphoma, leukaemia and some AI
SE: immunodeficiency because hypogammaglobulinaemia
What is infliximab, indications
Anti TNFr igG a cytokine used in RA
TNF a = bone erosion, cartilidge destruction, inflammation, malaise etc