Autoimmunity medical comic
This comic starts with Ehrlich's 'horror autotoxicus' and asks how the immune system normally avoids attacking itself. It explains tolerance in the thymus, bone marrow and periphery, then each way tolerance can fail — from regulatory T-cell loss to drugs, hidden antigens, molecular mimicry and epitope spreading — and the diseases that result.
For MBBS, NEET-PG, FMGE, NEXT and USMLE revision.
Autoimmunity: what the comic covers
High-yield points
- Autoimmunity is an immune response against self antigens; tolerance normally prevents it.
- Central tolerance deletes strongly self-reactive T cells in the thymus and B cells in the bone marrow.
- Peripheral tolerance uses anergy (no co-stimulation), activation-induced cell death through Fas, and suppression by regulatory T cells.
- Failure of Fas-mediated cell death is linked to SLE-like disease; loss of regulatory T cells removes the brakes.
- Drugs can alter red-cell antigens and trigger autoimmune haemolytic anaemia.
- Release of sequestered antigens (e.g. lens or sperm after injury) exposes self proteins the immune system never learnt to tolerate.
- Molecular mimicry — microbial antigens resembling self — explains diseases such as rheumatic fever after Group A Strep.
- Polyclonal B-cell activation, bystander inflammation and epitope spreading broaden the attack.
Quick questions
What is the difference between central and peripheral tolerance?
Central tolerance removes self-reactive lymphocytes as they develop, T cells in the thymus and B cells in the bone marrow. Peripheral tolerance controls those that escape, through anergy, activation-induced cell death and regulatory T cells.
What is molecular mimicry?
A microbial antigen that resembles a host protein, so antibodies or T cells made against the microbe cross-react with self. Rheumatic fever after streptococcal throat infection is the classic example.
What are sequestered antigens?
Self antigens normally hidden from the immune system, such as lens proteins or sperm. If injury releases them, they can trigger an autoimmune response.
Is this comic free to read?
The first pages are free to preview. Members read the full comic, and you can sign up free to read one comic in full.
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