15th lecture (autoimmune diseases) Flashcards
Define Systemic lupus erythematosus (SLE)
is an autoimmune disease in which the body’s immune system mistakenly attacks healthy tissue in many parts of the body
Rheumatoid arthritis (RA) description?
a long-term, progressive, and disabling autoimmune disease. It causes inflammation, swelling, and pain in and around the joints and other body organs. Rheumatoid arthritis (RA) usually affects the hands and feet first, but it can occur in any joint.
5x more frequent in females (relapsing and remissing disease)
-can affect small joints and also be more systemic involving the subcutaneous tissue, visceral surfaces, lungs and vessels.
Systemic sclerosis definition?
rare chronic disease of unknown cause characterized by diffuse fibrosis and vascular abnormalities in the skin, joints, and internal organs.
what are the factors that cause the development of Rheumatoid arthritis (RA)
Pathogenesis?
hereditary
environmental
patients with HLA dr4 are more susceptible to the disease.
what are the 5 autoimmune diseases that were discussed in the lecture?
- SLE (systemic lukos erythematosus)
- Rheumatoid arthritis
- systemic sclerosis
- Sjogren’s syndrome
- hashimoto syndrome
NOTE: these diseases can overlap.
in Rheumatoid arthritis (RA) what is the chain of events that cause the problems?
mostly the problem resides with the CD4 cells, which make cytokines. some antigens signal the proliferation of the CD4 cells and production of cytokines. These cytokines stimulate B-cells to make immunoglobulins.
The immunoglobulins are made against the immunoglobulins FC receptors.
So the antigen is the Fc fragment against which an antibody is made.
the antigen and the antibody are both immunoglobulins and they are called RHEUMATOID FACTOR.
The CD4 also initiate macrophages to release digestive enzymes that damage the tissue and generate inflammation.
The CD4 also causes synovial proliferation (joint tissue)
The CD4 also initiate RANK-L to initiate osteoclast formation (re-absorption of bone)
What are the morphological alteration of Rheumatoid arthritis?
- Joints: 1st affects smaller joints then they cause a ingrowing of the synovial tissue into the joints. This is called Pannus. The ingrowing of the tissue may destroy the cartilage surface of the joints and the deformed joint is called ANKYLOSIS.
- subcutaneous nodule: (a.k.a. rheumatoid nodules) in the middle fibrinoid necrosis and firboblasts around it and macrophages and lymphocytes (granulomatous reaction central firbinoid necrosis). can be seen in the serosal sheaths of the pleura, pericardium.
- vessels: acute necrotising vasculitis) can cause ischemic injury
- Lung: perialveolar area experiences firbosis, this causes increased resistance of the lung and cor pulmonale.
Define pannus?
an abnormal layer of fibrovascular tissue or granulation tissue. Common sites for pannus formation include over the cornea, over a joint surface (as seen in rheumatoid arthritis), or on a prosthetic heart valve
Define ankylosis?
abnormal stiffening and immobility of a joint due to fusion of the bones. which may be the result of injury or disease. The rigidity may be complete or partial and may be due to inflammation of the tendinous or muscular structures outside the joint or of the tissues of the joint itself.
what is the spectrum of an autoimmune disease?
It can be very mild and limited or very progressive and advanced.
systemic sclerosis.
also called scleroderma since its sclerosis of the skin (rigidity of the skin) is the main clinical simtoms. However other organs can be involved: SKIN, GI tract, Lung, Joints, Kidney. There are 2 types: -diffuse sclerodermal -limited sclerodermal
(systemic sclerosis) Diffuse sclerodermal, define it?
its a progressive disease, all part of the skin is involved and the patient has early visceral involvement, (the intestines are already affected).
- Skin: the fibrosis, sclerosis causes rigid skin, (the face looks like the skin is pulled back) shiny smooth fragile skin, sharp nose. Rigid finger movement and sharp edges.
- Gi tract: peristaltic movement is blocked and so is the absorption.
- Lung: perialveolar fibrosis (blocking gas exchange) cor pulmonale chronicum
- Joints: non-specific synovitis (synovial proliferation)
- Kidney: On the arterioles there is a proliferation of smooth muscle and then an onion skin-like thickening of the wall. Results in ischemic injury of the kidney.
(systemic sclerosis) Limited sclerodermal, define it?
the disease is located mostly on the face and fingers. The patient has late/mild organ involvement.
Its also characterized by the CREST syndrome;
C = calcinosis (microcalcification of fibrotic tissue, dystropic calcification)
R = raynaud phenomenon: (type of vascular disease characterized by a pale to blue to red sequence of color changes of the digits) when the hands are cold.
E = esophagus dysmobility (sclerosis of the esophagus resulting lack of peristalsis)
S = sclerodoetity (sclerosis of the fingers restricting movement)
T = Teleangicetiosis (a condition in which widened venules (tiny blood vessels) cause threadlike red lines or patterns on the skin)
Describe telangiectasia?
A condition in which widened venules (tiny blood vessels) cause threadlike red lines or patterns on the skin.
The vessels dilates in the area BEFORE the sclerotic plaque.
Describe raynaud phenomenon?
when the hands are exposed to the cold there is a vasoconstriction and then a vasodilation.
