Quiz 3 Flashcards
autoimmune disease definition
broad spectrum of illnesses caused by development of autoimmunity, or self-reactivity. development of antibodies against self-antigens/host where body fails to recognize its own tissue. can be mild to severe. frequently results in inflammation w/in targeted tissues/organs
rheumatology
medical specialty that examines autoimmune diseases
autoimmune lab tests:
erythrocyte sedimentation rate (ESR), C-reactive protein, antinuclear antibody (ANA), rheumatoid factor
erythrocyte sedimentation rate (ESR)
AKA sed rate. non-specific test used as a marker for inflammation, infection, neoplasm, and tissue necrosis or infarction. can have frequent false elevation. often used in vague symptomatology. NOT DIAGNOSTIC
pathophysiology of ESR test
acute phase reactants (fibrinogen and immunoglobulins) in blood during inflammation and infection increase positive charge, making RBCs (typically negative) more neutral. leads to stacking of RBCs called Rouleaux
Westergren tube
sedimentation tube used in ESR
normal ESR
0-20 mm/h
factors that can interfere w/ ESR results
microcytosis or anemia (increase), polycythemia (decrease), abnormally shapred RBCs (sickled cells, spherocytes - decrease)
ESR is elevated in:
inflammatory states, autoimmune disease, infection, malignancy, age, renal disease, obesity. (>100 mm/h –> infection)
c-reactive protein (CRP)
acute phase reactant. function is to recognize and respond to inflammatory mediators and target damaged tissue for clearance. levels elevate quickly after injury, decline after injury is removed. test is NOT SPECIFIC
C-reactive protein elevated in:
infection, pregnancy, post-exercise, obesity, depression, MI, malignancy, autoimmune disease, RA, trauma
antinuclear antibody (ANA) test
measures presence of autoantibodies towards proteins that are specific to the nucleic acids (DNA/RNA) or complexes involved with the DNA/RNA.
antinuclear antibody (ANA) test is important in diagnosis of:
systemic lupus erythematosus (SLE); also an indicator of several other autoimmune diseases (Progressive systemic sclerosis/PSS-scleroderma, RA, sjogren, dermatomyositis, polyarteritis)
systemic lupus erythematosus (SLE)
chronic autoimmune inflammatory disease that affects multiple joints and organs. manifests with: fatigue, weight loss, arthralgias, myalgias, lymphadenopathy, facial rash, multiple organ involvement. butterfly rash w/ sparing of nasal folds is characteristic of lupus
pathophysiology behind ANA test
identified through use of indirect immunofluorescence. serial dilutions used; highest dilution at which ANA detected is reported as a result. pattern is reported also (peripheral, diffuse, speckled, nucleolar)
range for ANA test results
any value less than 1:40 dilution is negative, while a value greater than 1:160 is strongly positive
progressive systemic sclerosis (scleroderma)
autoimmune disease that manifests w/: fatigue, arthralgias, myalgias, skin thickening and hardening (characteristic), digital ulcers, multiple systemic manifestations
sjogren syndrome
autoimmune disease that manifests with: diminished lacrimal and salivary gland function (dry eyes and mouth), vaginal dryness, rhinitis and sinusitis, increased risk of lymphoma
polymyositis/dermatomyositis
autoimmune disease that manifests w/: proximal skeletal muscle weakness, pulmonary disease, dysphagia, polyarthritis, dermatologic manifestations (various skin rashes)
rheumatoid arthritis (RA)
autoimmune disease that manifests w/: joint stiffness, pain, swelling (symmetrical!) and eventual deformity of MCP and PIP joints; systemic manifestations (fatigue, cardiovascular and renal disease). can shorten lifespan
normal rheumatoid factor value
less than 30 IU/mL
rheumatoid factor test
primary test to dx RA. normal less than 30 IU/mL. composed primarily of IgM antibodies directed against the Fc fragment on IgG antibody. levels increase w/ higher levels of disease activity/severity. not specific for RA
rheumatoid factor is increased in:
RA, autoimmune diseases, chronic infections such as hepatitis, malignancy
RA vs. OA
symmetry, age, systemic symptoms vs. localized pain