case 4 - painful joints Flashcards
What is inflammatory joint disease?
A condition involving autoimmunity to joint tissue, resulting in destruction of joint, loss of mobility, pain, etc.
What is degenerative arthritis?
Joint destruction caused by wear and tear to the joint
What is the difference between inflammatory joint disease and degenerative joint disease?
Inflammatory is caused by autoimmunity and affects many joints and causes systemic symptoms, while degenerative is caused by wear and tear to specific joints and has fewer systemic symptoms
What joints are typically affected in RA?
hands, wrists, feet, knees
What joints are typically affect in OA?
hands, back, knees, shoulders
What are the key systemic symptoms of RA?
Fatigue, anaemia of chronic disease, weight loss, fever
Why does RA cause fatigue?
Continuous inflammatory response results in cytokines that can trigger fatigue. Anaemia of chronic disease can reduce Hb, resulting in fatigue
What type of anaemia is common in patients with RA?
Anaemia of chronic disease - normocytic anaemia
Why does RA cause weightloss?
Proinflammatory cytokines, such as TNF, can cause weight loss
What are the key components of chronic disease management?
residential care, analgesic/anti-inflammatory use, mental health support, primary care, specialist team,
What are the members involved in a team approach to RA treatment?
GP, rheumatologist, physical therapist, occupational therapist, social worker, mental health professional, orthopaedic surgeon
What are the steps in RA development involving lymphocytes & macrophages?
1.) Inflammatory synovitis initiated when self-antigens presented to T-lymphocytes
2.) T cells recruit and activate macrophages and plasma cells in the synovium
3.) lymphocytes and macrophages produce cytokines (mostly TNF) that stimulates inflammation and cell proliferation, leading to cartilage destruction
4.) T cells activate osteoclasts leading to bone resportion
What immune interaction occurs to trigger RA?
Self-antigens are presented to T-cells
What cytokine is most heavily invovled with stimualting inflammation and cell proliferation in RA?
TNF (tumour necrosis factor)
How do T cells lead to the alteration of bone structure in RA?
T cells activate osteoclasts which leads to bone resorption
What is a pannus?
A chronically inflamed, thickened synovium found at the joint of patients with RA
What changes occur to the synovial membrane in patients with RA?
membrane becomes thick and opaque as synovial fibroblasts proliferate (pannus formation), pannus contains granulation tissue (is highly vascularised) then fibrosis occurs.
What is the consequence of the pannus being high vascularised in RA?
Leukocytes and inflammatory cytokines readily infiltrate the joint causing damage to cartilage
How does the pannus cause damage to articular cartilage in RA?
Invades the joint space and releases fluid containing proteolytic enzymes that erode cartilage matrix. The vascularisation also allows cytokines and chemokines to infiltrate and damage cartilage.
What are the changes to bone observed in RA?
Decreased bone mass at bone ends, eroded cartilage causes damage, bony ends may fuse together (bony ankylosis)
What 3 joint components show changes in RA and OA?
synovial membrane, articular cartilage, bone
What changes to the synovial membrane occur in OA?
inflammation and thickening in response to cartilage damage within the joint
Is there pannus formation in OA?
No, only slight thickening/inflammation of the synovial membrane
What changes occur to the articular cartilage in OA?
wear and tear thins cartilage narrowing the joint space, chondrocyte haemostasis altered leading to cartilage fibrillation.
What is cartilage fibrillation?
Sign of OA, splitting & fraying of articular cartilage, accompanied by local erosion and disintegration
What changes to bone occur in OA?
bone polishing (eburnation), increased density (sclerosis), fractures leading to subchondral cyst formation, osteophyte formation
What is eburnation?
In OA, the smooth polishing of bone ends to to loss of articular cartilage
What is bone sclerosis in OA?
Increased density of bone underneath damaged/lost cartilage
How are subchondral cysts formed in OA?
Small fractures in articulating bone surfaces can allow fluid to enter bone leading to subchondral cyst formation.
What is the name for the bony outgrowths that develop in OA?
Osteophytes
What are the key inflammatory mediators in RA?
cytokines (TNF alpha, IL-1, IL-6), chemokines
What releases the inflammatory mediators in RA?
Mostly macrophages
What is the role of TNF alpha in RA?
Cytokine, induces proliferation of synovial fibroblasts to form the pannus, activates osteoclasts for resorption
What is the role of IL-1 in RA?
Stimulates matrix degradation and chondrocyte apoptosis
What is the role of IL-6 in RA?
Cytokine, involved in synovial inflammation, pannus formation, osteoclast activation
What are the 3 key cytokines in RA inflammatory mediation?
TNF alpha, IL-1, IL-6
What is the role of chemokines in RA?
Immune cell recruitment to joints
What are the 3 key autoantibodies found in RA?
Rheumatoid factor, Anti-CCP antibodies, Anti-nuclear antibodies
What is Rheumatoid Factor an antibody to?
IgG
What is Rheumatoid Factor produced by?
B cells in lymphoid follicles in the synovium
What autoantibody is found in the plasma of the majority of RA patients
Rheumatoid Factor
What are Anti-CCP antibodies autoantibodies to?
Cyclic Citrullinated Peptides (CCP), which are citrullinated proteins that are thus foreign to the immune system in patients with autoimmunity.
What are Anti-nuclear antibodies autoantibodies to in RA?
Protein contents of cell nuclei