Immuno Flashcards
Feature of Treg cells
CD25+ and Foxp3
Reticular dysgenesis
AK2 mutation
Defect in haematopoietic stem cells –> ↓T cells, ↓B cells, ↓Neutrophils, ↓Monocyte/Macrophages, ↓RBC, ↓Platelets
Most severe form of SCID
Kostmann syndrome
HAX1 mutation
Congenital neutropenia syndrome (autosomal recessive)
↓neutrophils, -ve NBT/DHR, no pus
Cyclical neutropenia
Mutation in neutrophil elastase (ELA-2) Autosomal dominant Episodic neutropenia (every 4-6 weeks)
Leukocyte adhesion deficiency
Mutation in CD18 (β2 integrin subunit)
↑neutrophilia (in blood), no pus
Chronic granulamatous disease
NADPH oxidase deficiency –> absent respiratory burst
Excessive inflammation (ineffective neutrophil response)
Granuloma foramtion
Abnormal NBT/DHR test
Tests for whether neutrophils can produce hydrogen peroxide (resp burst)
Nitroblue tetrazolium (NBT) test: normal turns blue, abnormal is yellow Dihydrorhodamine (DHR) flow cytometry test: normal is fluoresent
IL-12 / receptor deficiency AND IFN-gamma / receptor deficiency
Macrophages interact with T cells via antigens OR cytokines
↑risk from mycobacteria
Classical NK deficiency
Mutation in GATA2
Functional NK deficiency
Mutation in FCGR3A
Reticular dysgenesis
AK2 mutation
Defect in haematopoietic stem cells –> ↓T cells, ↓B cells, ↓Neutrophils, ↓Monocyte/Macrophages, ↓RBC, ↓Platelets
Most severe form of SCID
X-linked SCID
Mutation in Foxp3 Mutation in common γ chain --> affects multiple cytokine receptors (T, NK development, Ig function) ↓↓T cells + NK cells or ↑B cells BUT ↓Igs Most common type of SCID
ADA deficiency
Deficiency of ADA (adenosine deaminase) –> required for lymphocyte maturation
↓T cells
↓B cells
↓NK cells
22q11.2 deletion syndrome (DiGeorge syndrome)
Deletion at 22q11.2 –> underdeveloped Thymus, Cleft palate, Underdevleoped parathyroids, Oseophageal atresia
↓T cells, ↓IgG
B cells, IgM
Bare lymphocyte syndrome (Type 2)
Absence of MHC Class II molecules ↓CD4 T cells CD8 T cells B cells IgM ↓IgG, ↓IgA (CD4 required for GC reactions)
Bare lymphocyte syndrome (Type 1)
Absence of MHC Class I molcules
↓CD8 T cells
Bruton’s X-linked hypogammaglobulinaemia
Bruton's BTK gene Boys no B cells ↓B cells ↓Antibodies T cells Absent γpeak (all antibodies) on protein electrophoresis
Hyper IgM syndrome
Mutation in CD40L (actually a T cell problem) --> no GC reaction B cells T cells ↑ IgM ↓IgG, ↓IgA, ↓IgE
Common variable immune deficiency (CVID)
↓IgGAM B cells T cells Unkown cause Presents in Adults
Selective IgA deficiency
Common (1 in 600)
2 in 3 –> asymptomatic
1 in 3 –> recurrent respiratory infections
↓IgA
HIV antibodies
Anti-gp120
Anti-gp41
Anti-p24 (gag capsid)
HAART is composed of
2 N-RTs + PI (or NNRTI)
Define AIDS
CD4 count < 200 cells / ul blood
Histology of immune rejection
Endothelial arteritis
Rupture of basement membrane
Inflammatory infiltrate with CD4, CD8 and Macrophages - cardial sign of rejection
Tubulitis
Basophilic strippling
NAME?
Target cells = Codocytes
- – Iron deficiency aenamia
- – Thalassaemia
- – Hyposplenism
Features of hyposplenism
Target cells
Howell-Jolly bodies
Test for pancreatic insufficiency
Faecal elastase
Coealic disease is associated with which HLA
HLA-DQ2 and HLA-DQ8
Familial mediterranean fever
Monogenic auto-inflammatory disease
Mutation in MEFV (encodes for Pyrin-Marenostrin) Periodic fever Peritonitis, Pericarditis, Arthritis ↑risk of AA amyloidosis Tx: Colchicine, Etanercept
APECED
Monogenic autoimmune disease
Mutation in AIRE –> failure of central tolerance for T cells –> autoreactive T cells
Multiple autoimmune disease - Hypoparathyroidism, Addison’s, Hypothyroidism, T1DM
Candidiasis
IPEX
Monogenic autoimmune disease
X-linked –> mutation in Foxp3 –> failure of development of Treg cells –> auto-antibody formation
Presents with 3Ds: Diarrhoea (autoimmune enteropathy), Diabetes, Dermatitis
ALPS
Monogenic autoimmune disease
Mutation in FAS pathway –> defect of apoptosis –> failure of tolerance (do not die when recognise self-antigen)
↑Lymphocytes
Autoimmunedisease
Lymphoma
Crohn’s disease
Polygenic auto-inflammatory disease
Genetic polymorphisms in NOD2
Ankylosing spondylitis
Mixed pattern disease
HLA-B27
Enthesitis, Sacroilitis (inflammation at sites of high tensile force)
Lower back pain, stiffness
Spinal fusion in vertebrae
Rheumatoid arthritis
Polygenic auto-immune disease
HLA-DR4 polymorphisms
PTPN22 polymorphisms
CTLA4 polymorphisms
Type III hypersensitivity
Antibody binds soluble antigen –> immune complxes –> deposit –> inflammation
- —- SLE (anti-dsDNA, ANA)
- — Rheumatoid arthritis (Anti-CCP, Rheumatoid factor = Anti-IgG IgM)
Type IV hypersensitivity
CD8 T cells recognise auto-antigen presented on HLA Class I molecules –> cell lyiss
CD8 T cells recogniseauto-antigen presented on HLA Class I molecules –> activation –> inlfmamation –> cell dmaage
—– T1DM (β cell antigen)
—– MS (myelin basic protein, proteolipid protein)
Auto-antibody in Pemphigus vulgaris
Anti-epidermal cadherin antibody
Auto-antibody in Grave’s disease (Type II)
Anti-TSH receptor antibody
Auto-antibody in Hashimoto’s thyroidis (Type II and Type IV)
Anti-thyroid peroxidase antibodies (Anti-TPO antibodies)
Anti-thyroglobulin antibodies (Anti-TG antibodies)
Auto-antibody in T1DM (Type IV)
Anti-islet cell antibody
Anti-insulin antibody
Anti-GAD antibody
Anti-IA-2 antibody (IA = islet antigen)
Auto-antibody in Pernicious anaemia (Type II)
Anti-IF antibody
Anti-parietal cell antibody
Auto-antibody in M gravis (Type II)
Anti-nAChR antibody
Weakness, worse with repetitive activity
Auto-antibody in Goodpasture’s disease (Type II)
Anti-GBM antibody (against Type IV collagen)
Smooth linear deposition
Renal biopsy: Crescentic nephritis
Rheumatoid arthritis (Type II and Type III and Type IV)
Anti-CCP antibody - most specific for RhA Rheumatoid factor (Anti-IgG IgM) HLA-DR1 and HLA-DR4 PAD2 and PAD4 polymorphisms PTPN 22 polymorphism
Lupus nephritis (Type III)
Immune complex deposition in GBM
Granular lumpy bumpy pattern
Most specific anitbody for SLE
Anti-dsDNA - most specific for SLE
Anti-nuclear antibody (ANA) is composed of
Anti-dsDNA (SLE)
ENA
—– Anti-Ro, La, Sm, RNP (SLE - any, Ro La = Sjogrens)
—– Anti-Scl70 (diffuse cutaneous systemic sclerosis)
—– Anti-Centromere (limited cutaneous systemic sclerosis)
Cytoplasmic
—- Anti-Jo-1 (myositis)
—- Anti-mitochondrial antibodies (PBC)
Anti-dsDNA staining pattern
Homogenous staining (highlights nucleus)
Anti-ENA staining pattern
Speckled pattern (Ro, La, Sm, RNP, Scl70, Centromere)
Anti-phospholipid anitbodies
Anti-cardiolipin antibody
Lupus anticoagulant
Limited vs Diffuse cutaneous systemic sclerosis
Limited SS
- CREST
- Skin involvement does NOT progress higher than forearms
- Anti-centromere
Diffuse SS
- CREST
- Skin involvement involves whole body
- Anti-Scl70
Dermatomyosis vs Polymyositis (Type IV)
Dermatomyositis = muscle + skin involvement
Polymyositis = muscle involvement ONLY
Sx - Heliotrope rash (periorbital), Gottern’s papules
Anti-Jo antibodies
Anti-Mi2 antibodies
Granulomatous polyangiits (Wegener’s granulomatosis)
c-ANCA (against proteinase 3)
Eosinophilic granulomatous polyangiits (Churg-Strauss syndrome)
and microscopic polyangiitis
p-ANCA (against myeloperoxidase)
Ipilimumab
Ab against CTLA4 –> ↑T cell response
Tx for melanoma
CALL MUM –> IpiliMUMab CtALL4
Pembrolizumab
Ab against PD-1 –> ↑T cell response
Tx for melanoma
Anti-proliferative immunosuppressants
Cyclophosphamide
Mycophenolate mofetil
Azathioprine
MOA: ↓DNA synthesis - celsl with rapid turnoever most sensitive
Cyclophosphamide
Alkylating agent
B cells > T cells
S/E: Haemorrhagic cystitis, PCP infection (Tx: septrin)
Azathioprine
Anti-metabolite
Metabolised to 6-mercaptopurine –> interferes with DNA synthesis
T cells > B cells
S/E: Bone marrow suppression - check TPMT activity first
Mycophenoalate mofetil
Anti-metabolite
Blocks de novo Guanosine nucleotide synthesis
T cells > B cells
S/E: PML (infection with JC virus)
Calcineurin inhibitors
Example: Ciclosporin, Tacrolimus
MOA: ↓Calcineurin –> ↓T cell activation
Useful in Transplant, Psoriasis, SLE
JAK inhibitors
Example: Tofacitinib
MOA: Interferes with JAK-STAT cytokine signalling –> ↓Cytokine production
Useful for Rheumatoid arthritis
PDE4 inhibitors
Example: Apremilast
MOA: Inhibition of PDE4 –> ↑cAMP –> ↓Cytokine production
Useful for Psoriasis
Peddy Premi (PD4E inhibitor, Apremilast)
Anti-thymocyte globulin
MOA: Thymocytes injected into rabbit, then extract antibodies –> inject into human –> immunosupression on T cells
Useful for Transplantation
Basiliximab
MOA: Anti-CD25 antibody –> ↓T cell proliferation
Useful for Transplantation
“25 leaves of basil”
Abatacept
MOA: CTLA4-Ig fusion protein against CD80 and CD86 –> ↓T cell activation
Useful for Rheumatoid arthritis
Rituximab
MOA: Anti-CD20 antibody –> depletes B cells
Useful for Lymphoma, RhA, SLE
Natalizumab
MOA: Antibody against α4 integrin –> ↓transmigration of WBC
Useful for MS
“Nαtαlizumab”
Tocilizumab
MOA: Anti-IL-6 receptor antibody –> ↓Macrophage, T cell, B cell, Neutrophil activation
Useful for Castleman’s disease, Rheumatoid arthritis
Toc-IL-6-zumab
Anti-TNF-αantibodies
Example: Infliximab
Useful for RhA, Ank Spond, Psoriasis, IBD
TNF αantagonists
Example: Etanercept
MOA: TNF-αreceptor against to IgG Fc –> binds to TNF-α(decoy receptor)
Useful for RhA, Ank Spond, Psoriasis
Usteinumab
MOA: Antibody against IL-12 and IL-23
Useful for Psoriasis, Crohn’s disease
Guselkumab
MOA: Antibody against IL-23
Useful for Psoriasis
Secukinumab
MOA: Antibody against IL-17 A
Useful for Psoriasis, Ank Spond
Secukin = 7 -umab = teen Seven-teen = IL-17
Denosumab
MOA: Antibody against RANK-L –> ↓bone resorption
Useful for Osteoporosis