Section 4 Autoimmune Diseases
1. Definition:
An immune reaction against “ selfantigens” is the cause of certain
diseases in human.
2. Mechanism
(1) Alteration of self-proteins (modification
of the molecule)
① Partial degradation of autoantigens.
② Complexing of self-antigens with drugs
or micro-organisms.
(2) Hidden antigens exposure
(3) Cross-reactions (molecular mimicry)
① Antibodies to streptococcal antigens may
react with constituents of cardiac muscle or
connective tissue in rheumatic fever.
② Rabies vaccine may rise to encephalitis
(4) Breakdown of tolerance
① Bypass of helper T cell tolerance
② Imbalance of suppressor-helper T cell
function
③ Geneic fators
④ Emergence of a sequestered antigen
⑤ Polyclonal lymphocyte activation
3. Classification
(1) Systemic autoimmune diseases
① Systemic lupus erythematosus (SLE)
a. Definition: It is the classic prototype
of the multisystem disease of
autoimmune origin.
Model for the pathogenesis of systemic lupus erythematosus. .
(From Robbins Basic Pathology ,2003）
Slide 7.23
Lupus nephritis. There are two focal necrotizing lesions at 11 and
2 o’clock. (H&E stain.) (Dr. Helmut Rennke)
(From Robbins Basic Pathology ,2003）
Slide 7.24
Lupus nephritis, diffuse proliferative type. Note the marked increase in
cellularity throughout the glomerulus. (H&E stain.) (Dr. Helmut Rennke)
(From Robbins Basic Pathology ,2003）
Slide 7.25
Immunofluorescence micrograph stained with fluorescent anti-IgG from a patient
with diffuse proliferative lupus nephritis. One complete glomerulus and part of
another one are seen. Note the mesangial and capillary wall deposits of IgG. (Dr.
Helmut Rennke) (From Robbins Basic Pathology ,2003）
Slide 7.26
Lupus nephritis showing a glomerulus with several “wire loop” lesions
representing extensive subendothelial deposits of immune complexes. (Periodic
acid-Schiff [PAS] stain.) (Dr. Helmut Rennke)
(From Robbins Basic Pathology ,2003）
Slide 7.28
Systemic lupus erythematosus involving the skin. A, An H&E-stained section
shows liquefactive degeneration of the basal layer of the epidermis and edema
at the dermoepidermal junction. (Dr. Jag Bhawan) B, An immunofluorescence
micrograph stained for IgG reveals deposits of immunoglobulin along the
dermoepidermal junction. (Dr. Richard Sontheimer)
(From Robbins Basic Pathology ,2003）
Slide 7.29
Libman-Sacks endocarditis of the
mitral valve in lupus
erythematosus. The vegetations
attached to the margin of the
thickened valve leaflet are easily
seen. (Dr. Fred Schoen)
(From Robbins Basic Pathology ,2003）
Slide 7.30
b. Characteristics
(i) Immunologically, the disease involves a
bewildering
array
of
auto-antibodies,
particularly antinuclear antibodies (ANAs).
(ii) Anatomically, all sites of involment have in
common vascular lesions with fibrinoid
deposits.
(iii) Clinically, it is an unpredictable remitting,
relapsing disease of acute or insidious in the
body, but principally affects the skin, kidneys,
serosal membranes, joints and heart
② Sjogren’s syndrome（口眼干燥综合征）
Definition: It is a clinicopathologic entity
characterized by dry eyes and dry mouth
resulting from immunologically mediated
destruction of the lacrimal and salivary
glands.
Sjogren’s syndrome. A, Enlargement of the salivary gland. (Dr.
Richard Sontheimer). B, The histologic view shows intense
lymphocytic and plasma cell infiltration with ductal epithelial
hyperplasia. (Dr. Dennis Burns) (From Robbins Basic Pathology ,2003）
Slide 7.31
③ Scleroderma(硬皮病）
④ Rheumatoid arthritis
⑤ Polymyositis（多发性肌炎）
⑥ Polyarteritis nodosa （结节性多动脉炎）
Note the extensive deposition of dense collagen in the dermis with
virtual absence of appendages and thinning of epidermis. (Dr. Trace
Worrell) (From Robbins Basic Pathology ,2003）
Slide 7.33
The extensive subcutaneous fibrosis has virtually immobilized the
fingers, creating a clawlike flexion deformity. Loss of blood supply
has led to cutaneous ulcerations. (Dr. Richard Sontheimer)
(From Robbins Basic Pathology ,2003）
Slide 7.34
Note the rash affecting the eyelids. B, Dermatomyositis. The
histologic appearance of muscle shows perifascicular inflammation
and atrophy. C, Inclusion body myositis showing a vacuole within a
myocyte. (Dr. Dennis Burns) (From Robbins Basic Pathology ,2003）
Slide 7.35
(2) Organ-specific diseases
①Hashimoto’s disease (chronic lymphocytic
thyroiditis)
② Graves’s disease
③ Goodpasture’s syndrome
④ Insulin-dependent diabetes mellitus
⑤ Primary billiary cirrhosis
⑥ Chronic ulcerative colitis
⑦ Malignant pernicious anaemia with
chronic atrophic gastritis
⑧ Chronic active hepatitis
⑨ Myasthenia gravis
Slide 26.8
Hyperthyroidism
(Offered by Prof.Orr）
Hyperthyroidism
Slide 26.11
Hashimoto’s thyroiditis
(From Robbins Basic Pathology ,2003）
Slide 26.9