Rhuematoid Arthritis

Question 1

DAS assessment in management

Answer 1

A score called the Disease Activity Score (DAS) to support a targeted combination treatment to escalate therapy as needed to control disease activity:

• DAS scores below 2.6 indicate remission (i.e. free from symptoms)
• DAS scores between 2.6 to 3.2 indicate low disease
• whereas scores between 3.2 to 5.1 indicate moderate disease levels.
• DAS scores above 5.1 indicate high disease levels: start biologics

A change in DAS scare of less than 0.7 means no response

Question 2

Genetic Associations of Rheumatoid Arthritis

Answer 2

HLA DR4 (a gene often present in RF positive patients) - most common

HLA DR1 (a gene occasionally present in RA patients)

Question 3

Diagnosis

Answer 3

Bloods:

• CRP, ESR
• Rheumatoid Factor
• Anti-CCP

X- ray:

• Loss of joint space
• Erosions (periarticular)
• Soft tissue swelling
• Subluxation
• • Periarticular osteopaenia

Question 4

Clinical Features

Hand features

Answer 4

• pain and stiffness in the small joints of the hands and feet, : wrist, ankle, MCP and PIP joints in the hands
• Z shaped deformity to the thumb
• Swan neck deformity (hyperextended PIP with flexed DIP)
• Boutonnieres deformity (hyperextended DIP with flexed PIP)
• Ulnar deviation of the fingers at the knuckle (MCP joints)

Question 5

Ocular manifestations

Most common

Answer 5

keratoconjunctivitis sicca (most common)
episcleritis (erythema)
scleritis (erythema and pain)
corneal ulceration
keratitis

Question 6

What can happen in the neck in RA

Answer 6

Atlantoaxial subluxation occurs in the cervical spine.

The axis (C2) and the odontoid peg shift within the atlas (C1).

This is caused by local synovitis and damage to the ligaments and bursa around the odontoid peg of the axis and the atlas.

Subluxation can cause spinal cord compression and is an emergency.

This is particularly important if the patient is having a general anaesthetic and requiring intubation.

MRI scans can visualise changes in these areas as part of pre-operative assessment.

Question 7

Management

NICE guidelines

Monitoring progress

Flares

Answer 7

NICE: DMARD monotherapy +/- a short-course of bridging prednisolone.

DMARDs

• methotrexate is the most widely used DMARD
• sulfasalazine (safer in pregnancy)
• leflunomide
• hydroxychloroquine (safer in pregnancy)

Biologics
Infliximab - monoclonal antibody against TNF
Etanercept - anti TNF
Rituximab - anti CD20

Monitoring response to treatment: CRP and disease activity (using a composite score such as DAS28) to assess response to treatment

FLARES:
flares of RA are often managed with corticosteroids - oral or intramuscular

Question 8

Notable side effects of DMARDs and biologics

Answer 8

All have a risk of hepatoxicity

• Methotrexate: pulmonary fibrosis and risk of myelosuppression
• Leflunomide: Hypertension and peripheral neuropathy
• Sulfasalazine: Male infertility (reduces sperm count)
• Hydroxychloroquine: Nightmares and reduced visual acuity
• Anti-TNF medications: Reactivation of TB or hepatitis B
• Rituximab: Night sweats and thrombocytopenia

Question 9

Complications

Answer 9

Felty’s Syndrome: Rheumatoid arthritis, neutropaenia, splenomegaly

Amyloidosis