Rheumatoid Arthritis

Pathophysiology of Rheumatoid Arthritis

rheumatoid arthritis is:

1)  systemic autoimmune disease of unknown cause
2) hallmark is chronic, symmetric, destructive inflammatory synovitis in peripheral joints

Signs and Symptoms

1) fatigue
2) anorexia
3) weakness
4) myalgia
5) pain, swelling, and tenderness in joints of hands, wrists, knees, and feet
6) morning stiffness lasting > 1 hour
7) fever
8) lymphadenopathy
9) splenomegaly
10) neck pain and stiffness
11) pain and swelling in TMJ
12) scleritis (eye pain, vision loss)
13) pericarditis and pericardial effusions
14) coronary arteritis
15) pleurisy and pleural effusions
16) pulmonary fibrosis and hypertension (usually in men only)
17) amyloid deposition in kidney
18) osteoporosis
19) rheumatoid nodules on extensor surfaces (Achilles tendon, olecranon)
20) vasculitis (polyneuropathy, cutaneous ulceration, small brown spots on nails)

Characteristic Test Findings

Laboratory

1) rheumatoid arthritis is marked by positive rheumatoid factor in two thirds of patients
2) anemia
3) thrombocytosis
4) increased sed rate, C-reactive protein, and haptoglobin

Radiology

5) pulmonary nodules on chest radiograph

Histology and Gross Pathology

1) cartilage destruction and bone erosion is usually pronounced in rheumatoid arthritis
2) fibrous/bony ankylosis
3) soft tissue contractures
4) synovial proliferation with fibrinoid granulomas

Associated Conditions

1) increased incidence with cigarette smoking, HLA-DR4 and HLA-DR1 and parvovirus B19 infections
2) increased incidence of Baker’s cyst, dilation of ascending aorta, autoimmune hepatitis, and carpal tunnel

Biochemistry

1) possibly immune response to an infectious agent (Lyme disease, parvovirus, CMV, EBV, rubella, mycoplasma)
2) antibodies to RA-33, filaggrin, and calpastatin

Inheritance/Epidemiology

1) genetic predisposition exists
2) more common in whites
3) female to male, 3:1

Treatment

1) aspirin, NSAIDS,Cox-2 inhibitors
2) low-dose glucocorticoids
3) methotrexate, sulfasalazine, D-penicillamine
4) alpha-interferon
5) immunosuppressive drugs (cyclosporine, cyclophosphamide)
6) many patients with rheumatoid arthritis report good pain relief with acupuncture

Tips for USMLE

1) rheumatoid factor is not specific to rheumatoid arthritis
2) rheumatoid factor is found in 10% of 60 year olds that do not have rheumatoid arthritis
3) pain in affected joints is worsened by movement
4) if lower back pain is mentioned, it is not RA (affects only the neck)
5) Felty’s syndrome is RA, splenomegaly, neutropenia, and sometimes anemia and thombocytopenia
6) if “Z” deformity of hand (radial deviation of wrist and ulnar deviation of fingers) or “boutonniere deformity (flexed proximal finger joints and extended distal finger joints) are mentioned, think rheumatoid arthritis