Rheumatology Flashcards
Granulomatous inflammation of the media and predominantly involves medium to smaller branches of carotid vessels is what?
Giant cell arteritis.
Transmural inflammation of the arterial wall with Fibrinoid necrosis is what?
Polyarteritis nodosa.
Note: usually idiopathic, but assoc with HBV in 30% of cases.
Medial band-like calcifications is what?
Monckeberg’s medial calcific sclerosis – pipestem
Hyaline arteriolosclerosis is associated with what?
Diabetes, HTN, age
Hyperplastic arteriolosclerosis is associated with what?
Severe HTN
Weight lifter who attempts to lift very heavy weight and suddenly drops the weight is due to mm contraction inhibited by the reflex response initiated by what?
Golgi tendon organ (inverse stretch reflex)
Fcn: protect mm and CT from injury
Stimulated with excessive tension –> reflex inhibition of mm. Induces inhibitory postsynaptic potential on the alpha motor neuron
Which structure in the mm actively initiates the patellar reflex arc?
Spindle affarents fibers –> spinal cord –> dorsal root –> ventral horn –> synapse with alpha motor neuron –> innervate mm.
Radiographic exam of osteoarthritis shows what?
osteophytes
Thickening of joint capsule
Subchondral bone formation
Radiographic exam of RA shows what?
Pannus formation and subcutaneous nodules along with ulnar deviation and subluxation
Radiographic exam of osteochondroma shows what?
Radiodense bony spike covered with radiolucent cap of cartilage
Dermatomyositis is a CT disease that can cause dysphagia how?
Affects striated (skeletal) mm - UPPER THIRD of the esophagus is striated mm Note: middle and distal third is smooth mm
How can you differentiate multiple myeloma vs Paget disease of the bone lesions?
Multiple myeloma - punched-out lytic bone lesions
Pagets - patchy areas with inc and dec bone density
CD4+ T cells induce B cells to syntheize rheumatoid factor and ___ in rheumatoid arthritis?
Anti-citrullinated protein antibodies (more specific).
Note: RF is an IgM antibody specific for the Fc component of IgG
RA frequently affects what part of the spine?
Cervical
How does SLE lead to low complement levels?
Binding of autoantibodies to self antigens –> deposition of immune complexes in tissues and consumption of complement
Posture-dependent lower extremity pain (relieved by spinal flexion), numbness/paresthesia, and weakness. MCCs?
Spinal stenosis
MCCs - degenerative arthritis of the spine (disc herniation, ligamentum flavum hypertrophy, osteophyte formation)
Back pain relieved by rest and is positional
Degenerative (osteoarthritis)
Back pain relieved with exercise; prolonged morning stiffness
Spondyloarthropathy (HLA-B27)
Back pain after recent infection, IV drug abuse, immuno comp, systemic infections)
Vertebral osteomyelitis
Back pain worse at night, not responsive to position changes
Spinal mets
Gout occurs with inc freq in patients with activating mutations in what?
Phosphoribosyl pyrophosphate synthetase (PRPP) - inc production and degradation of purines
NSAIDs and colchicine both inhibit what cell type for treatment of gout?
neutrophils
What are the lab values of PTH, ca, and phosphorus in patients with osteoporosis?
Normal
What are lab values of PTH and ca in patients with humoral hypercalcemia of malignancy?
High Ca
low PTH
Also seen in vit D toxicity, excess Ca ingestion, thyrotoxicosis, and immobilization
Calcipotriene, calcitriol, and tacalcitol treat psoriasis how?
Topical vit D analogs that bind vit D receptor (NUCLEAR transcription factor of activated T cells) and inhibit keratinocyte proliferation and stimulate keratinocyte differentiation
Ustekinumab (stelara) targets what for psoriasis treatment?
IL-12 and IL-23 –> inhibit differentiation and activation of CD4+ Th1 and Th17 cells
Etanercept MOA?
TNF-a inhibitor added to methotrexate to treat moderate to severe RA in patients who have failed methotrexate alone
Acts as a DECOY receptor - NOT a monoclonal antibody unlike the other TNFa inhibitors infliximab, adalimumab, and certolizumab.
Also treats mild to moderate psoriasis
Cyclosporine MOA?
Inhibits NFAT (nuclear factor of activated T cells) from entering the nucleus and modulating transcription activity –> impaired production and release of IL-2 and inhibiting IL-2 induced activation of resting T-lymphocytes
Calcineurin inhibitor; binds cyclophilin (note: tacrolimus also inhibits calcineurin, but binds FK506)
Tx psoriasis
Trabecular thinning with fewer interconnections
osteoporosis
Subperiosteal resorption with cystic degernation
Hyperparathyroidism
Excessive unmineralized osteoid (low minearl density)
Vit D def
Persistence of primary unmineralized spongiosa in medullary canals
Osteopetrosis
sirolimus MOA?
binds immunophilin FK-506 binding protein (FKBP) in the cytoplasm –> inhibit mTOR –> blocks IL-2 signal transduction
Use: immunosuppressant
Note: mTOR functions as a serine/threonine protein kinase that regulates cell growth, cell proliferation, cell motility, cell survival, protein synthesis, autophagy, and transcription
MTOR integrates the input from upstream pathways, including insulin, growth factors (such as IGF-1 and IGF-2), and amino acids.[9] mTOR also senses cellular nutrient, oxygen, and energy levels.
What autoantibody assoc with SLE is assoc with removal of introns from RNA transcripts?
SnRNA (Anti-Smith) - synth by RNA pol II in nucleus and complexes with specific proteins to form snRNPs
What lab finding reflects osteoblast activity?
Alkaline phosphatase
Note: Tartrate-resistant acid phosphatase, urinary hydroxyproline and urinary deoxypyridinoline reflect osteoclastic activity
The initial phase of Pagets disease involves inc activity of what cell type?
Osteoclasts –> osteoblast
Bx shows mosaic pattern of lamellar bone
Osteogenesis imperfecta defect?
Cant synthesize Type 1 collagen - cant form bone matrix
Note: defective bone mineralization is characteristic of vit D def
Patient with history of watery penile d/c, but swabs neg for gonococcal infection. 2 weeks later, sx include acute conjunctivitis, knee pain and vesicular rash on palms and soles. Cause?
Reactive arthritis - also assoc with sacroiliitis. Preceding infx could be chlamydia, Salmonella, shigella, yersinia, Campy, C diff
Note: Syphilis would present with maculopapular or pustular rash on palms and soles (not vesicular)
Differentiate Class I HLA proteins from Class II HLA proteins
Class I - Expressed by all nucleated cells and present endogenous ag to CD8 cytotoxic T cells. eg Ankylosing spondylitis
Class II - expressed by APCs and present foreign ag to CD4 helper T cells. eg RA, T1DM, celiac disease
How can endotracheal intubation in patients with long-standing hx of RA cause flaccid paralysis with decreased or absent reflexes?
Intubation worsens vertebral subluxation and causes compression of the spinal cord. Paralysis eventually becomes spastic as spinal shock resolves over the ensuing days to weeks
Meds assoc with osteoporotic fractures
Anticonvulsants that induce CYP450
Aromatase inhibitors, medroxyprogesterone
GnRH agonists
PPIs
Glucocorticoids, unfractionated heparin, thiazolidinediones (pioglitazone, rosiglitazone)
Polymyalgia rheumatica is assoc with what vasculitis?
What is the primary mech underlying this vasculitis?
Giant cell vasculitis
Polymyalgia rheumatica sx - neck, torso, shoulder and pelvic girdle pain and morning stiffness.
MOA - cell-mediated immunity. Production of cytokines, in particular, IL-6 is an important driver of this process
What does CREST syndrome stand for?
Calcinosis
Raynaud
Esophageal dysmotility - fibrous replacement of muscularis of lower esophagus
S - sclerodactyl
T - telangiectasias
Note: fingertip ulcers can be seen d/t chronic ischemic tissue damage
polymyositis is characterized by symmetric proximal mm weaknesss. It is assoc with autoantibodies to what?
Biopsy shows endomysial mononuclear inflam infiltrate and patchy mm fiber necrosis.
Antinuclear and anti-Jo-1 (anti-histidyl-tRA synthase) autoantibodies. Endomysial inflam with CD8 T cells
Note: similar to dermatomyositis but lacks the characteristic skin findings. Dermatomyositis is perimysial inflam with CD4+ T cells
How does multiple myeloma cause hypercalcemia?
Local IL-1, TNF and RANKL effects.
IL-1 is also called osteoclast activating factor
What hypercoagulable condition results in falsely elevated PTT?
Antiphospholipid antibody syndrome (SLE)
Anticardioplpin, anti-b2-glycoprotein I, and lupus anticoagulant are examples of these abs.
HLA-B27 (eg ankylosing spondylitis) can be tested for how?
Analysis of class I MHC allele expression
Which can cause inc risk of gout?
- smoking
- ETOH
- Working in textile factory
ETOH
Woman with headache, HTN, bruit over L costovertebral angle and L renal stenosis with aneurysmal diltation (string of beads sign) will show what on renal artery histo?
Intimal fibroplasia - Fibromuscular dysplasia
FMD have been reported mimicking the following conditions: polyarteritis nodosa, Ehlers-Danlos’s syndrome, Alport’s syndrome, pheochromocytoma, Marfan’s syndrome, and Takayasu’s arteritis.
In osteopetrosis, what cell type is defective?
Osteoclasts - deficiency of carbonic anhydrase in osteoclasts can cause defective H+ pumping by osteoclasts –> defective bone resorption by osteoclasts, as an acidic environment is needed for dissociation of calcium hydroxyapatite from bone matrix.
