Question
A 25 year old woman suffered from weakness in the eye muscles (as shown in the image) which later progressed to weakness in the proximal limb muscles.Weakness is typically least severe in the morning and worsens as the day progresses.
and it gets increased by exertion and alleviated by rest.The auto-immune condition which the patient is suffering from is a which type of hypersensitivity reaction ?
A. Type 1.
B. Type 2.
C. Type 3.
D. Type 4.
Show Answer
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Correct Answer » B
Explanation
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Ans:B. Type 2
The patient in question is suffering from Myasthenia Gravis
Myasthenia gravis (MG) is a rare autoimmune disorder of neuromuscular transmission in which antibodies form against acetylcholine nicotinic postsynaptic receptors at the neuromuscular junction of skeletal muscles.
Hypersensitivity reaction
- Hypersensitivity is a set of undesirable reactions produced by the normal immune system, including allergies and autoimmunity.
Comparison of hypersensitivity types
| Type |
Alternative names |
Often mentioned disorders |
Mediators |
| I |
Allergy (immediate) |
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| II |
Cytotoxic, antibody-dependent |
- Autoimmune hemolytic anemia
- Rheumatic heart disease
- Thrombocytopenia
- Erythroblastosis fetalis
- Goodpasture’s syndrome
- Graves’ disease
- Myasthenia gravis
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- IgM or IgG
- (Complement)
- MAC
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| III |
Immune complex disease |
- Serum sickness
- Arthus reaction
- Rheumatoid arthritis
- Post streptococcal glomerulonephritis
- Membranous nephropathy
- Lupus nephritis
- Systemic lupus erythematosus
- Extrinsic allergic alveolitis (hypersensitivity pneumonitis)
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- IgG
- (Complement)
- Neutrophils
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| IV |
Delayed-type hypersensitivity, cell-mediated immune memory response, antibody-independent |
- Contact dermatitis.
- Mantoux test
- Chronic transplant rejection
- Multiple sclerosis
- Celiac Disease
- Hashimoto’s thyroiditis – Some type 2. Mostly type 4.
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| V |
Autoimmune disease, receptor mediated |
- Graves’ disease
- Myasthenia gravis
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Type V hypersensitivity reaction
- This is an additional type that is sometimes (often in the UK) used as a distinction from Type 2.
- Instead of binding to cell surfaces, the antibodies recognise and bind to the cell surface receptors.