Rheumatology Flashcards
What is the aetiopathogenesis of rheumatoid arthritis?
Unknown but it is recognised that it probably results from a combination of genetic and environmental factors leading to breakdown of immune tolerance.
What are the other autoimmune diseases as well as RA associated with in terms of aetiopathogenesis?
Associated with MHC:
* Rheumatoid Arthritis (RA): HLA-DR4 (more frequent in smokers)
* Systemic Lupus Erythematosus (SLE): HLA-DR3, complement components
* Progressive systemic sclerosis (PSS): HLA-DR3
- Immunological associations: serology often positive for a variety of autoantibodies
- Histology shows evidence of immune involvement
What are the auto-antibodies present in RA?
-RF (rheumatoid factor) present in RA, but non-specific
-95% specific to RA is the anti-CCP (anti-citrullinated protein antibodies)
What are auto-antibodies?
Antibodies produced by the immune system that mistakenly target and attack the body’s own tissues.
What are the auto-antibodies present in systemic lupus erythematosus (SLE)?
ANA (antinuclear antibodies), specifically dsDNA antibodies
What is the auto-antibody present in progressive systemic sclerosis (PSS)?
Scl 70
What are the auto-antibodies present in Sjogren’s syndrome?
ENA (extractable nuclear antigen) antibodies (Ro, La) as well as RF.
What are rheumatoid factors?
Auto-antibodies which target and attack IgG antibodies or IgM produced by the body itself.
This leads to inflammation, joint damage etc.
How prevalent is RA?
1% of population is affected with a female predisposition in the ratio F:M being 2.5:1.
What is RA?
-Symmetrical polyarthritis which often starts in hands and wrists.
-It’s a systemic disease which may have extra-articular movement.
-This means RA doesn’t only affect joints but also other organs and systems in the body.
What are the symptoms and signs of RA?
Symptoms:
-Pain
-Swelling
-Morning stiffness
-Malaise (fatigued)
-Non-articular symptoms
Signs:
-Swelling
-Warmth
-Tenderness
-Limited movement
-Deformity
What can advanced RA look like?
-Bountonniere deformity of thumb (z-shaped)
-Ulnar deviation of metacarpophalangeal joints
-Swan neck deformity of fingers
What does the anatomy of a RA joint look like compared to a healthy joint?
In the RA joint:
1.The synovial membrane is thickened
2.There’s an overgrowth of the synovia sites (pannus)
3.Marked influx of inflammatory cells; each of those producing cytokines which stimulates inflammation
4.Osteoclasts get activated to eat away at the bone
5.Cartilage overlying the bone is getting damaged and removed
6.Swelling of the overlying soft tissues is caused; there’s damage to the ligaments and structures supporting the joints
7.The joint itself also gets damaged
What does the pannus look like histologically?
slide 20
What are some of the complications of RA?
-rheumatoid nodules
-Tendon rupture
-Normochromic, normocytic anaemia
-Nerve entrapment e.g. median nerve
-Vasculitis - a group of conditions that cause inflammation of the blood vessels.
-Atlanto-axial subluxation
-Eye complications
How are patients with RA treated?
Analgesia (e.g. NSAIDs reduce pain and swelling)
DMARDs especially methotrexate, hydroxychloroquine for mild to moderate
TNFa blockade e.g. Infliximab, Etanercept
Anti-B cell monoclonal ab e.g. rituximab
What is the relevance of RA to dentistry?
Hand deformity - oral hygiene, blister packs
Carpal tunnel syndrome
Atlanto-axial subluxation during GA
TMJ dysfunction
Sjogren’s syndrome
Anaemia
Complications of systemic treatment
What is Sjogren’s syndrome?
An autoimmune disease which can cause oral and ocular dryness.
It can either be a primary disease (dry eyes, mouth, vagina, etc.) or it can be secondary to other autoimmune diseases (e.g. RA, PSS, SLE)
What is the incidence of Sjogren’s syndrome and who is most likely to get it?
It’s quite rare but it’s much more common in females (F>M 9:1) with 2 peaks of onset: mid 30s and then postmenopausal 45-60 due to reduction is oestrogen
What are the symptoms of Sjogren’s syndrome?
-Sicca symptoms (95%): dryness of mouth, eyes, skin, vagina
-Excessive fatigue (75%)
-Arthralgia - pain in joints without joint inflammation.
-Myalgia - muscle pain/aching
-Dental caries
-Loss of teeth
-Candida
-Swollen salivary glands and Lacrimal glands
If you have Sjogren’s syndrome, what is there also an increased risk of?
Lymphoma/maltoma
Have to look out for B cell lymphoma, mucosal associated lymphoid tissue
What investigations are required in order to diagnose Sjogren’s syndrome?
- Measure salivary flow, whether it’s stimulated or unstimulated:
-For stimulated parotid flow, normal is >0.4ml/min
-For unstimulated whole salivary flow, normal is >0.2ml/min
- Schirmer test
- Do bloods: FBC, inflammatory markers, auto-antibodies Ro and La, others as indicated
- Ultrasound (has largely replaced sialography & scintigraphy)
- Labial gland biopsy
What is the relevance of Sjogren’s syndrome to dentistry?
-Xerostomia: Dental caries, Loss of teeth, Candida
-Salivary gland enlargement
-Complications of systemic treatment
What are the variants of lupus erythematosus?
- Discoid lupus (DLE)– scarring skin lesions/oral (affects either just skin or just mouth)
- Subacute cutaneous (SCLE)- rash, systemic disease (predominantly affects skin but has some features of systemic disease)
- SLE (predominantly systemic but might include skin rash/oral lesion)
- Anti-phospholipid syndrome (sticky blood, prone to clots)
- Drug-induced lupus
