Arthritis What is it and what causes it? Matt Brown Professor and - - PowerPoint PPT Presentation

Arthritis

What is it and what causes it?

Matt Brown

Professor and Director of Genomics Queensland University of Technology Matt.brown@qut.edu.au

What is Arthritis?

• Any disease of joints
• Divided into:

– Immune-mediated arthritis eg rheumatoid arthritis, psoriatic arthritis, lupus, ankylosing spondylitis – Metabolic arthritis eg. Gout – ‘Wear and tear’ arthritis e.g. osteoarthritis – Infectious arthritis e.g Ross River Fever, septic arthritis And over 100 other forms of arthritis

How Common Is Arthritis?

• Affects 3.5 million Australians

– By 2050 will affect 7 million Australians

• Is the major cause of both disability and

chronic pain in Australia

• Costs Australia $23.9 billion in medical costs

and lost income

Bates, et al. Arthritis and disability: Social Policy Research Centre, UNSW, Australia, 2014

What Makes You at Risk for Arthritis?

• Genes

– Either single genes or multiple genes operating in combination

• Environment

– Diet – Smoking – Occupation – Infections – …

Human Genetic Diseases

• Single gene ‘monogenic’

diseases

– e.g. cystic fibrosis, haemochromatosis,

• steogenesis imperfecta

– Generally rare – Each family usually has a different mutation, usually in the same gene – Evident inheritance from generation to generation

Monogenic forms of arthritis

• Very rare (<0.5% of population)
• Includes

– Some types of

• Metabolic arthritis

– Gout – Chondrocalcinosis

• Disorders of joint and cartilage formation
• Blood disorders

– Haemophilia – Sickle cell disease

Common ‘polygenic’ diseases

• e.g. osteoarthritis, rheumatoid

arthritis, psoriatic arthritis, ankylosing spondylitis

• Different individuals have different

genetic variants in different, but

• verlapping, sets of genes
• Condition ‘runs in the family’ but

transmission from generation to generation not so obvious

The Environment and Arthritis

• Smoking

– Increases risk of RA, AS – May reduce risk of OA

• Alcohol

– Increases risk of gout, OA

• Weight

– Increases risk of OA and psoriatic arthritis

• Occupation

– Farmers at higher risk of hip and knee OA

Do Gut Bacteria Cause Arthritis?

• Compared gut bacteria in cases with

ankylosing spondylitis with healthy controls

• Cases have different gut bacteria to

health controls

• Consistent with either disease

affecting the bacteria, or the bacteria causing the disease. Costello et al., Arthritis Rheumatol, 2015

Rehaume LM et al. Arthritis Rheumatol. 2014 Oct;66(10):2780-92.

Summary

• Mostly the cause of arthritis is in your genes.
• Environmental factors are also important, so

you can do things to help prevent arthritis.

• Most inflammatory arthritis is thought

ultimately to be caused by infections triggering the immune system to attack joints

– ?Can we use this to prevent or treat arthritis?