S3: autoimmunity

Question 1

Define autoimmunity

Answer 1

Immune response against the host due to the loss of immunological tolerance of self-antigens

Question 2

Define autoimmune disease

Answer 2

Conditions caused by tissue damage or disturbed physiological responses due to an immune response against self-antigens

Question 3

Compare organ specific vs non-organ specific autoimmunity

Answer 3

Organ specific: one or multiple self-antigens within one single organ or tissue
Non-organ specific: widely distributed self-antigens throughout the body

Question 4

Describe the causes of autoimmune diseases

Answer 4

Autoantibody driven: complement activation, antibody-mediated cell cytotoxicity & neutrophil activation
Autoreactive T cell driven: cytotoxic T cells, macrophages
Both are hypersensitivity reactions

Question 5

Outline the set of criteria for the diagnosis of a disease as autoimmune

Answer 5

1) Presence of autoantibodies/autoreactive T cells
2) Levels of autoantibodies correlate with disease severity
3) Autoantibodies/autoreactive T cells found at the site of tissue damage
4) Transfer of auto-antibody/autoreactive T cells to a healthy host induces the autoimmune disease
5) Clinical benefit provided by immunomodulatory therapy
6) Family history

Question 6

List autoimmunity triggers

Answer 6

Genetic factors
-increased risk with an affected sibling
-increased risk with an affected identical twin
-AIRE mutations that affect central tolerance
-autoimmune disease associated with MHC variants
Environmental factors
-hormones
-infections
-drugs

Question 7

List current and future therapeutic strategies for autoimmune diseases

Answer 7

Plasma exchange
Immunosuppressive drugs
Anti-inflammatory drugs
Replacement therapy
Surgery
MONOCLONAL ANTIBODIES

Question 8

Describe systemic lupus erythematosus patient prolife

Answer 8

Female to male 9:1
Race: Afro-Caribbean > south Asians > Caucasians
Genetic factors
Environmental factors – smoking

Question 9

Describe history taking for lupus

Answer 9

SOCRATES
Constitutional symptoms – fever, fatigue, weight loss, night sweats (rule out cancer)
Glove and sweater approach
-gloves: raynauds, joint pains & hand rash
-sweater: hair loss, eye + mouth dryness, nose bleeds, mouth ulcers

Question 10

Describe investigations for lupus

Answer 10

Routine bloods: FBCs, U&Es, LFTs, CRP
-CRP in lupus is usually normal, if raised there is an infection
Autoantibodies/lupus associated bloods

Question 11

Describe treatment for lupus

Answer 11

Patient education – lifestyle modification, sunscreen
Start DMARDs – hydroxychloroquine, azathioprine & mycophenolate
Steroids – prednisolone, methylprednisolone
Severe cases – IV cyclophosphamide

Question 12

List the lupus mnemonic

Answer 12

A RASH POINTS Medical Diagnosis
ANA positive, renal abnormalities, arthralgia/arthritis, serositis, haematologic abnormalities, photosensitivity, oral ulcers, immunological abnormalities, neurologic abnormalities, malar rash/discoid rash
4/11 = definite lupus

Question 13

Describe rheumatoid arthritis patient profile

Answer 13

Female to male 3:1
Prevalence 1%
No race predilection
Genetic factors & environmental factors (poor dental hygiene)

Question 14

Describe the treatment for rheumatoid arthritis

Answer 14

Start DMARDs early – methotrexate, hydroxychloroquine, sulfasalazine & leflunomide
Steroids – prednisolone, methylprednisolone
Combination therapy is usual