Autoimmunity Flashcards
Types of adaptive immunity
Cell Mediated
Humoral immunity
Defects in what can trigger autoimmunity?
Any part of the immune system
What is the bodys first line of defence?
Sentinel cells
Where are sentinel cells found?
Kupffer cells (liver) Langerhans cells (skin / mucosa) Alveolar macrophages (in lungs) Microglia (brain) Dendritic cells Mast cells and specialised T cells (blood) Macrophages
What do sentinel cells lead to?
Increased temperature
Complement cascade
Inflammation
Adaptive immunity consists of ….
T cells
B cells
Central control of tolerance features
Thymus
inactivation of cells required for initiation of immune response
Negative selection ensures only those that work make it out of the thymus
Peripheral control of tolerance features
Inhibition of the expression of the immune response
Treg cells - Th17 cells
Types of antigen presenting cells (APCs)
Professional
Atypical
Types of professional APCs
DCs
Macrophages
B cells
Types of atypical APCs
Mast cells
Basophils
Eosinophils
ILC3s
What makes up the major histocompatibility complex?
Human leucocyte antigen (HLA)
Chromosome 6
What does a working immune system have?
Recognition Interaction Response Elimination Control and regulation
Does autoimmunity equal autoimmune disease?
NO
What is autoimmunity?
Physiological autorecognition with secondary epiphenomena
The failure of an organism in recognising its own constituent parts as non self OR you having immunity to you
Pathology of autoimmunity
Cell mediated Antibody mediated Immune complex autoimmunity Environmental Genetic
Autoimmunity and T1DM
Autoreactive T cells against pancreatic islet cell antigens leading to destruction and non-production of insulin
Autoimmunity and Crohn’s disease
Triggered by a foreign pathogen leading to APC presentation
Autoreactive T cells against intestinal flora antigens leading to lymphocyte infiltration of exocrine glands
Can be familial (NOD2 gene)
Autoimmunity and psoriasis
Autoreactive T cells against skin associated antigens
What occurs in autoimmune disease?
Immune response contributing directly to tissue / organ damage
Which gender is more at risk of getting an autoimmune disease?
F > M
Causes of autoimmune disease
Unknown Immune regulation Hormonal - F > M Genetic factors - HLA Environmental - UV / sun - Bacterial - Chemical agents
What is myasthenia gravis a disease against?
The NMJ
Pathology of myasthenia gravis
Autoreactive T cells and B cell ACH receptor antibodies
Presentation of myasthenia gravis
Weakness
Fatigability
What is myasthenia gravis associated with?
Thymoma
Pathology of MS
T cells specific to myelin, cross the BBB and release cytokines
BBB damage, macrophage and Tc cell migration attacks oligodendrocyte
Despite Treg cells allowing healing, eventually the damage becomes worse
What is MS associated with?
HLA-DR2
Vit D deficiency
Features of organ specific autoimmune disease
Antigens are localised to given organ or tissue
Lesions are confined to target organ or tissue
They overlap with other organ specific antibodies and diseases
Features of non organ specific autoimmune disease
Antigens have widespread distribution throughout the whole body
Multiple organs and tissues are affected
Immune complexes deposit in joints, skin and kidneys
Overlaps with other non organ specific antibodies and diseases
Examples of organ specific autoimmune diseases
Autoimmune thyroid disease - graves - hashimotos Myasthenia gravis Pernicious anaemia Diabetes mellitus
Examples of non organ specific autoimmune diseases
SLE
RA
systemic sclerosis
Systemic vasculitis
Treatment of autoimmune disease
Immunosuppressive therapy Anti-inflammatory therapy Plasmapheresis Stem cell / Bone marrow transplant Replacement of lost physiological factor Organ / tissue / mechanical graft
