Table of Contents
Definition / general | Epidemiology | Sites | Pathophysiology | Clinical features | Diagnosis | Laboratory | Radiology description | Radiology images | Case reports | Treatment | Clinical images | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Molecular / cytogenetics description | Molecular / cytogenetics imagesCite this page: Shankar V. Rheumatoid arthritis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/jointsra.html. Accessed June 1st, 2023.
Definition / general
- Chronic systemic inflammatory disorder affecting synovial lining of joints, bursae and tendon sheaths; also skin, blood vessels, heart, lungs, muscles (Davidson College: Rheumatoid Arthritis [Accessed 26 January 2022])
- Produces nonsuppurative proliferative synovitis, may progress to destruction of articular cartilage and joint ankylosis
Epidemiology
- 1% of adults, 75% are women, peaks at ages 10 - 29 years; also menopausal women
Sites
- Small bones of hand affected first (MCP, PIP joints of hands and feet), then wrist, elbow, knee
Pathophysiology
- Triggered by exposure of immunogenetically susceptible host to arthitogenic microbial antigen; autoimmune reaction then occurs with T helper activation and release of inflammatory mediators and cytokines that destroys joints; circulating immune complexes deposit in cartilage, activate complement, cause cartilage damage
- Parvovirus B19 may be important in pathogenesis (Mod Pathol 2003;16:811)
Clinical features
- Clinical course: variable; malaise, fatigue, musculoskeletal pain, then joint involvement; joints are warm, swollen, painful, stiff in morning; 10% have acute onset of severe symptoms but usually joint involvement occurs over months to years; most damage occurs in first 5 years, joints are unstable with minimal range of motion; 50% have spinal involvement
- Reduces life expectancy by 3 - 7 years, death due to amyloidosis, vasculitis, GI bleeds from NSAIDs, infections from steroids
Diagnosis
- Morning stiffness, arthritis in 3+ joint areas, arthritis in hand joints, symmetric arthritis, rheumatoid nodules, rheumatoid factor, typical radiographic changes
Laboratory
- 80% have IgM autoantibodies to Fc portion of IgG (rheumatoid factor), which is not sensitive or specific; synovial fluid has increased neutrophils (particularly in acute stage), increased protein, low mucin
- Other antibodies include antikeratin antibody (specific, not sensitive), antiperinuclear factor, anti rheumatoid arthritis associated nuclear antigen (RANA)
Radiology description
- Xray: joint effusions, juxta-articular osteopenia, erosions and narrowing of joint space; destruction of tendons, ligaments and joint capsules produce radial deviation of wrist, ulnar deviation of digits, swan neck finger abnormalities
Radiology images
Case reports
- 30 year old woman with 7 year history of pain in lumbosacral area and 1 year history of pain in joints of both hands (Chin Med J (Engl) 2011;124:3430)
- 49 year old woman with chief complaint of restricted mouth opening without pain, lasting approximately 4 months (Braz Dent J 2012;23:779)
- 52 year old woman had pain in the right wrist joint for 6 months (Case #308)
- 72 year old woman with 6 month history of progressive painful swelling of wrists (Int J Surg Case Rep 2011;2:208)
- Woman with pain and edema in second, third and fourth proximal interphalangeal (PIP) joints of hands and wrists (Rev Bras Reumatol 2012;52:648)
Treatment
- Nonsteroidal anti-inflammatory drugs (NSAIDs); immunosuppressive drugs; joint replacement (synovitis tends to lessen), synovectomy (inflamed synovium may recur and disease may continue to progress)
Gross description
- Joints have edematous, thick, hyperplastic synovium, covered by delicate and bulbous fronds
- Osteophytes and new bone formation are not prominent
Microscopic (histologic) description
- Dense perivascular inflammatory infiltrate of T lymphocytes, plasma cells (often with eosinophilic cytoplasmic inclusions called Russell bodies), macrophages; inflammation extends to subchondral bone (relatively specific for rheumatoid arthritis)
- Proliferative synovitis with synovial cell hyperplasia and hypertrophy
- Lymphoplasmacytic infiltrate with variable germinal centers, necrobiotic nodules and fibrosis
- Increased vascularity with hemosiderin deposition
- Organizing fibrin floating in joint space as rice bodies
- Neutrophils present on synovial surface; osteoclasts present in bone forming cysts
- Erosions, osteoporosis; pannus formation (synovium, synovial stroma with inflammatory cells, granulomatous tissue, fibroblasts), progressing to fibrous ankylosis (bridges joints), then ossifying to form bony ankylosis
- Minimal evidence of repair (proliferative cartilage, sclerotic bone or osteophytes)
- Weichselbaum's lacunae: enlarged chondrocyte lacunae within articular cartilage due to dead chondrocytes
- Skin: rheumatoid nodules in 25%, usually those with severe disease in skin subject to pressure (ulnar forearm, elbows, occiput, lumbosacral area); also present in viscera; firm, nontender, with central fibrinoid necrosis surrounded by palisading epithelioid histiocytes, lymphocytes, plasma cells; obliterative endarteritis in vasa nervorum and digital arteries causes ulcers, neuropathy, gangrene
- Blood vessels: small to medium size vessels in vital organs (not kidney) affected by severe erosive disease; rheumatoid nodules present, high titers of rheumatoid factor
Microscopic (histologic) images
Cytology description
- May have inflammatory exudate with neutrophils, suggesting an infectious arthritis
Molecular / cytogenetics description
- > 20 genetic risk factors
- HLA-DR4, DR1 (65%); PADI4 (Immunogenetics 2011;63:459)
- T cell antigen receptor motif Q(K/R)RA in 75%
- IL2 signalling pathway involved in T cell activation and proliferation (Curr Opin Rheumatol 2010;22:109)