Download File - Sheffield Peer Teaching Society

Phase 2a Revision Session
Faiza Shafiq and Natasha Ngonyamo
06/03/17
The Peer Teaching Society is not liable for false or misleading information…
Learning objectives
• Innate immunity
• Adaptive immunity
• Autoimmune diseases
– Type 1 diabetes mellitus
– Hashimoto’s thyroiditis
• Hypersensitivity and allergy
– Asthma
• Immunodeficiency
– HIV
Definitions
• Immunity
• Ability to ward off disease/ disease causing
organism
• Innate Immunity
• Present at birth
• Non-selective
• No memory
• Adaptive immunity
• Built up over time
• Specific
• Memory response (to previous disease/
vaccination)
Innate vs Adaptive
Immunity
• Innate
–
–
–
–
Barriers
Inflammation
Interferon
Macrophage/
opsonisation
– Phagocytosis/ MAC
• Adaptive
–
–
–
–
–
Lymphocyte
B cells, T cells
MHC
Lymphoid organs
Mast cells
The Peer Teaching Society is not liable for false or misleading information…
Innate Immunity
Cellular component
•
•
•
•
•
Neutrophils
Macrophages
Lymphocytes
Basophils
Eosinophils
Chemotaxis
The Peer Teaching Society is not liable for false or misleading information…
Adherence
Phagocytosis
Adaptive immunity
• Antigen presenting cells
• Mainly macrophages
• Dendritic cells
• Some B cells
• Major histocompatibility
complex (MHC)
• Proteins that mark a cell as
self
• Class 1- all cells
• Class 2- Certain immune
cells
• T helper cells
• Stimulate proliferation of
other T cells
• Stimulate B cells
• Cytotoxic T cells
• Destroy infected body cells
(apoptosis)
• B cells
• Produce antibodies
Immunology in Disease
Autoimmune diseases
• Definition
– A disease in which the body produces antibodies
that attack its own tissues, leading to a
pathological process
• What autoimmune conditions do you know
of?
Type 1 Diabetes Mellitus
Clinical Features
•
•
•
•
•
•
•
•
Polyuria
Polydipsia
Weight loss
Lethargy
Fatigue
Recurrent infections
Juvenile onset
DKA
Diagnosis
• Fasting glucose >/=7.0mmol/L
• OGTT >/= 11.1mmol/L
• HbA1c 48mmol/mol
Management
• Lifestyle factors
• Insulin!!!!
– What do we need to watch out for?
Hashimoto’s Thyroditis
• Destruction of thyroid cells by various cell
and antibody-mediated immune processes
• Antibodies blocking the TSH receptors have
been described
Clinical features
Diagnosis and Management
• Diagnosis
– TFTs
– Autoantibodies
• Anti- thyroid peroxidase (anti-TPO)
– 90% of patients
• Anti-thyroglobulin antibodies
– Less specific
– Also found in Grave’s disease
• Management
– Levothyroxine
Allergy and Hypersensitivity
Asthma
Clinical presentation
• Signs
– Polyphonic wheeze
– Hyperinflated chest
– Increased RR
– Low oxygen Sats
– Long expiratory phase
– Use of accessory
muscles
• Symptoms
– SOB
– Cough
– Diurnal variation
– Triggers
– History of atopy
– Chest tightness
Diagnosis
• Spirometry
– FEV1/FVC <0.7
• Reversibility of symptoms with bronchodilator
Management
Immunodeficiency
• Primary immunodeficiency syndromes
– Antibody deficiency
• Selective IgA deficiency
– Cell mediated immunity deficiency
• Thymic aplasia (DiGeorge syndrome)
• Severe combined immunodeficiency disease (SCID)
• Secondary immunodeficiency syndromes
– Malnutrition
– HIV
– Drugs- cytotoxic, immunosuppressants
Human Immunodeficiency Virus
(HIV)
• HIV virus specifically targets cells expressing
CD4
– Mainly CD4 T cells
– Causes CD4 T cell depletion
• Direct cytotoxicity
• Immune system over-activation
• Sexual transmission
Clinical Features
Acute Primary HIV Infection
•
•
•
•
•
•
•
•
•
FEVER 38°C - 40°C
Sore throat
Sweats ++
Diarrhoea
Headache
Myalgia + arthralgia
Mild hepatosplenomegaly & lymphadenopathy
Rash
Mouth ulcers
Clinically Latent Phase
• Persistent generalised lymphadenopathy
Early Symptomatic HIV
•
•
•
•
•
•
Oral candidiasis
Oral hairy leukoplakia
VZV
CIN
Peripheral neuropathy
Constitutional symptoms
AIDS
• CD4 count <200
• Resp
– Pneumocystis jiroveci pneumonia
– Bacterial pneumonia – strep pneumoniae
– TB
• CNS
– Cerebral toxoplasmosis
– Tuberculoma
– Meningitis
• Neoplasms
–
–
–
–
Kaposi’s sarcoma
Cervical neoplasia
Lymphoma
Molluscum contagiosum
Management
• Highly active anti-retroviral therapy
• Aim to reduce viral load to <50 copies/ml and
increase CD4 count