Immuno - case studies Flashcards
2 types of latex allergy
Type I - spectrum of severity from wheeze + urticaria –> anaphylaxis
Type IV - CONTACT DERMATITIS
Immediate management of anaphylaxis - 7 points
- Airway management
- O2
- IM adrenaline 500mcg
- IV fluids
- IV chlorpeniramine +
- hydrocortisone
- Inhaled salbutamol
Specific pt groups at risk of Type I allergy to latex
PREM
Indwelling latex devices (eg for hydrocephalus)
Multiple urological proedures
Why is tropical fruit allergy significant in latex allergy
Cross reactivity
Eg of latex containing products in healthcare setting
BP cuff Gloves Catheters Face masks Bandages Steth
For which allergens is desensitisation actually useful? state 2
Insect venom
Grass pollen
Disorders associated with recurrent meningococcal meningitis
Complement deficiency
Antibody deficiency
Any disruption to BBB
What kinda infections make you suspicious of an immunodeficiency?
SPUR Serious Persistent Unusual Recurrent
Suspected complement deficiency - what Ix are ordered?
C3
C4
CH50
AP50
Complement components in classical pathway
C1
C2
C4
Complement components of the alternate pathway
Factor B H I (from bacterial cells wall)
Complement components of the final common pathway
C5-9
Normal C3
Normal C4
Absent CH50
Absent AP50
What does this indicate?
Deficiency in final common pathway
Tests to investigate lupus nephritis?
Urinalysis (proteinuria + haematuria)
urine microscopy - red cells + casts
Renal biopsy
SLE - what kinda hypersensitivity disorder is it?
Type III: immune complex mediated
antinuclear antibodies bind to bare cells. these complexes activate complement + attract WBCs
wtf is adalimumab
humanised anti-TNFalpha
MOA of cyclophosphamide?
Which cells are most affected
Alkylates guanine
- affects B cells>T cells
Rituximab - which cells does it deplete?
mature B cells (but not plasma cells)
MMF - which cells does it affect?
T cells>B cells
Azathioprine - which cells does it affect
T cells
Penicillin for CAP –> 3 days later:
Fever, arthralgia, vasculitic skin rash, proteinuria, haematuria, raised transaminases, disorientation
Serum sickness
WTF is the pathophysiology behind serum sickness
Penicillin is recognised as a neo-antigen: SENSITISATION. stimulates a strong IgG response
On next exposure –> IMMUNE COMPLEX FORMATION w circulating penicillin + mass IgG production –> complex deposits in glomeruli + skin + joints
Clinical features of serum sickness
Arthralgia
Renal dysfunction
Purpuric rash
(immune complex deposition in small vessels)
Ix to confirm Dx of serum sickness
- complement levels - LOW due to immune complex activation
- specific IgG to penicillin
- Skin and kidney biopsies
Serum sickness: Type of hypersensitivity disorder
Type III
FTT +recurrent infections (tonsillitis, pneumonia, ROM, cellulitis):
Ddx?
CF DM Bruton's SCID Hyper IgM Cytokine deficiency
having ATOPIC DISEASE
Evaluation of lymphocyte immunodeficiency - which Ix?
T-cells (CD4 + 8)
B-cells
IgM, IgA, IgG
Ix for suspected phagocyte deficiency
NBT
Neutrophil count
Leukocyte adhesion markers
Treatment of Bruton’s
Immunoglobulin replacement every 3 weeks
Why are multiple myeloma patients susceptible to infections
The mass clonal proliferation of one plasma cell –> suppresses production of normal Ig
Why are multiple myeloma patients often anemics?
Crowding out of normal RBCs in bone marrow by plasma cells
Tumour releases cytokines which inhibits normal bone marrow function
Why is ESR elevated in Multiple Myeloma
High protein content in plasma –> increases attractant charge
RBCs tend to clump together so they fall more quickly through plasma.
X-ray lesions in multiple myeloma
lytic lesions “punched out”
How is recent childbirth significant in rheumatoid arthritis
In pregnancy, Th2 cells tend to predominate and then return to Th1 post-partum
Which class of Ig is rheumatoid factor? what does rheumatoid factor target
Rheumatoid factor is an IgM which targets Fc portion of human IgG
what does anti-CCP stand for
anti-cyclic citrullinated protein
what is CCP? how are they formed?
arginine residues are converted to citrulline residues by PADI enzymes
What can affect the degree of CCP generation?
Polymorphisms in PADI enzymes - type 2 and 4
2 HLA associations with Rheumatoid arthritis?
DR1
DR4 (Dw4, 14, 15)
PADI stands for?
Peptidylarginine deiminase
PADI enzymes are important cosssss whyyyy
PADI enzymes act to turn arginine residues into citrulline residues
Polymorphisms (type 2 and 4) lof PADI –> more citrulline resiudes –> more likely to develop RA
PTPN22 is an enzyme important in rheumatoid arthritis. what is its function?
PTPN22
- suppresses T cell activation
In RA, the 1858T allele increases RA susceptibility
Genetic predisposition to Rheumatoid arthritis
- HLA DR1 + 4
- PTPN22 - 1858T allele
- PADI enzyme (PMs type 2 + 4)
1st line tx of rheumatoid arthritis
DMARDs inc methotrexate
If methotrexate is not tolerated - which DMARds are used for rheumatoid arthritis
Sulphasalazine
Hydroxychloroquine
name 2 anti-TNFalpha agents
infliximab
Adalimumab
Tocilizumab - MOA? use?
Anti-IL6 receptor
Rheumatoid arthritis
Beyond DMARDs - state 4 diff drugs used to treat Rheumatoid arthritis
Infliximab (anti-TNFa)
Abatacept (anti-CTLA4)
Tocilizumab (anti-IL6)
Rituximab (depletes B cells, anti-CD20)
Natalizumab - MOA? use?
MOA: anti-alpha4 intern
Use: relapsing remitting MS
Use for basiliximab
prevention of transplant rejection
