Rheumatoid Arthritis 11/05

1. Rheumatoid Arthritis11/05 Stephanie Boade Silas, M.D. Division of Rheumatology, UUMC

2. Objectives • Know the epidemiology and risk factors of rheumatoid arthritis. • Have a basic understanding of the pathology and pathogenesis of RA. • Know the distinctive musculoskeletal and extraarticular clinical features of RA. • Understand how labs and imaging studies are used to make a diagnosis of RA.

3. Rheumatoid Arthritis • Chronic, systemic inflammatory disease • 1% of North American Caucasians • Peak incidence 4th to 6th decades • Females 2-3X > Males • Pathogenesis unknown

4. Pathogenesis • Synovial Hyperplasia • Hypercellularity • Inflammatory cells • Joint effusions • Pannus • Invasive synovium • Erodes cartilage and bone

5. Normal Joint Diagram

6. Normal PIP joint

7. Normal Synovium • Synovial lining • Loosely organized • 1-3 cell layers • Type A = MΦ • Type B = fibroblast • Subsynovium • Few cells • Scattered vessels, nerves, lymphatics

8. Rheumatoid Synovium • Synovial lining • Hyperplasia • 10 cell layers thick • Subsynovial • T cells: CD4>CD8 • Dendritic cells • MΦ • B cells/Plasma cells • RF • Vast blood supply

11. Rheumatoid Ankle -- Pannus • Unique to RA • Synovial fibroblast cells migrate over cartilage surface • Transformed phenotype • RANKL-RANK • Osteoclasts at interface

13. RA: Erosions

14. Pathogenesis of Rheumatoid Arthritis Choy, E. H.S. et al. N Engl J Med 2001;344:907-916

15. Inflammatory Mediators • Cytokines • Products of activated macrophages and fibroblasts • IL-1, TNF-α, IL-6 • Th-1 cell-driven disease • TNF-α, IL-2, IFNγ, IL-12 • Recruit/activate inflammatory cells • Angiogenesis • Adhesion molecule expression

16. Inflammatory Mediators • Chemokines • Cell surface proteins • Adhesion molecules, membrane bound TNF, RANKL • Costimulatory molecules • CD80 or CD86 on APC bind CD28 T cell • CTLA-4 on T cell also binds CD80/86 – inhibits costim. • Enzymes • Matrix metalloproteinases (MMPs) • Transcription factors • NF-κB, AP-1 • Complement/Immune complexes

17. Cytokine Signaling Pathways Involved in Inflammatory Arthritis Choy, E. H.S. et al. N Engl J Med 2001;344:907-916

18. Genetic Monozygotic twins 15-30% concordance HLA-DR4 Shared epitope HLA-DRB1 *0401, 0404, 0101 Homozygosity Increased risk Increased severity Gender Nulliparity 3 mo. after pregnancy Infections Proteus, Mycoplasma EBV, Parvo, HTLV-1 Cigarette smoking Age RA – Etiology/Risk Factors

19. RA -- Clinical Features • Morning stiffness = hallmark of inflammatory joint disease • Joint inflammation – Synovitis/Effusions • Warmth, swelling, (erythema) • Structural changes • Cartilage loss, bony erosions, periarticular damage

20. Joint Distribution • Predominantly peripheral synovial joints • Hand and Feet • Symmetric involvement • Hands predominate • Wrist • MCP’s • PIP’s • Not DIP’s

21. RA: Joint distribution

22. Synovitis

23. RA - hands

24. Ulnar deviation at MCP’s Radial deviation at wrists Swan-neck deformities Boutonniere deformities Tendon nodules Tendon rupture 3rd, 4th, and 5th extensor tendons Carpal tunnel syndrome Ulnar neuropathy RA Hand Deformity

25. Swan neck and Boutonniere

26. Ulnar Deviation

27. RA- extensor tendon rupture

28. Carpal Tunnel Syndrome

29. RA - Knees • Symmetric lateral and medial joint space loss • Effusions • Synovial proliferation • Baker’s cyst • Posterior herniation of joint capsule • May rupture • Hx and U/S can distinguish • Crescent-sign on exam

30. Popliteal Cyst

32. Ruptured Baker’s Cyst

33. RA - feet • MTP synovitis • Direct palpation • Global lateral/medial squeezing • MTP subluxation • Cock-up deformities of toes • Callous formation on soles • Ankles - synovitis/effusions • Tarsal tunnel syndrome -- medial foot and sole paresthesias

34. MTP subluxation

35. Cock-up deformity

36. RA - Cervical Spine • Apophyseal joint destruction • C4-5 and C5-6 most common • Atlantoaxial Instability • C1-C2 • Tenosynovitis of transverse ligament of C1 • Erosion of odontoid process of C2 • Cranial settling • Neck/Occiput pain, Paresthesias, Pathologic reflexes

37. Atlantoaxial Instability

38. Constitutional sx’s Fever/fatigue/wt loss Osteopenia Muscle weakness Skin Eye Lung Kidney Cardiac Vascular Sjogren’s Neurologic Hematologic Felty’s RA—Extraarticular Features

39. Extraarticular Features • Rheumatoid nodules (15%) • Central necrosis surrounded by palisading fibroblasts and lymphocytes • Subcutaneous, bursal, tendon sheaths • Extensor surfaces / Pressure points • Forearms • Achilles • Ischial area • MTP’s • Flexor surface of fingers

40. Rheumatoid nodules

41. RA - Chronic changes

42. Extraarticular manifestations • Vasculitis • Leukocytoclastic vasculitis • Palpable purpura • Vasculitic lesions on fingers • Mononeuritis multiplex • Visceral involvement (PAN)

43. RA - Vasculitis

44. RA - Vasculitis

45. Extraarticular RA -- Ocular • Sicca symptoms • Episcleritis • Scleritis

46. Scleromalacia perforans

47. Extraarticular Manifestations • Pulmonary • Pleural effusions • Interstitial lung disease • Nodules • Cardiac • Pericarditis -- < 10% clinically • Myocarditis • Atherosclerosis – 3X increased risk of CAD

48. RA: Pulmonary nodules

49. RA: Pulmonary fibrosis

50. Hematologic • Anemia of chronic disease • Low Fe, Low TIBC, Ferritin > 40 - 100 • Felty’s syndrome • Triad • RA • Splenomegaly • Neutropenia • Frequent infections/Leg ulcers • Iron deficiency anemia (NSAIDs)