Wk 7: Rheumatology Flashcards
Rheumatology
1) Define it
2) What does it include? How many conditions?
1) Subspecialty focused on diagnosis and treatment of medical diseases of the joints, muscles, and connective tissues
2) A wide spectrum of disorders related to the musculoskeletal system, including systemic inflammatory and autoimmune diseases that may also involve other organ systems
-Over 200 conditions
The rheumatology autoimmune component focuses on what?
Especially joints and connective tissues
Give 4 examples of conditions studied by rheumatology
1) Rheumatoid Arthritis
2) Systemic lupus erythematosus (SLE)
3) Fibromyalgia
4) Chronic pain syndromes
List 5 rheumatology labs
1) CBC
2) Urinalysis and creatinine
3) Creatine phosphokinase (CPK/CK)
4) Erythrocyte sedimentation rate (ESR)
5) C-Reactive Protein (CRP)
CBC:
1) When may WBCs be increased?
2) When may WBCs be decreased?
1) In conditions where immune system is attacking itself (inflammation)
2) If they are being attacked (WBC destruction)
Urinalysis and creatinine:
1) Protein and blood are seen in urine when ______________ affects kidneys
2) These can also show decreased __________ function
1) vasculitis affects kidneys
2) kidney
Creatine phosphokinase (CPK/CK) is increased when ______________ are attacked (such as polymyositis)
muscles
Erythrocyte sedimentation rate (ESR):
1) What increases it?
2) What are RBC rouleaux (singular: rouleau)?
1) Inflammation > increased proteins in plasma (increased viscosity) > RBCs stack up and settle faster (heavier) = increased ESR
2) Stacks of RBCs
Name a highly sensitive positive acute phase reactant
C-Reactive Protein (CRP)
1) Acute phase reactants were first discovered thanks to discovery of CRP in _____________ patients.
2) “Acute phase response” accompanies what inflammatory states, acute or chronic? Define this phrase as well.
1) pneumonia
2) Accompanies acute and chronic inflammatory states; adaptive changes in concentration of certain plasma proteins
Acute phase response:
1) What is it associated with? Give examples
2) When may less significant changes occur?
3) What is the specific benefit/ function of an acute phase reactant?
1) Wide variety of disorders, including: infection, trauma, infarction, inflammatory arthritides, other systemic autoimmune and inflammatory diseases, and various neoplasms
2) During metabolic stress
3) Varies according to acute phase reactant
Define acute phase reactants
Proteins whose serum concentrations increase or decrease by at least 25% during inflammatory states
1) Define positive acute phase reactant
-Give examples
2) Define negative acute phase reactant
-Give examples
1) Positive: plasma concentration increases by at least 25%
-ESR (indirect APR; reflects plasma viscosity and presence of acute phase proteins), CRP, fibrinogen, haptoglobin, hepcidin, ferritin, procalcitonin
2) Negative: plasma concentration decreases by at least 25%
-Albumin, transferrin, antithrombin
RA (rheumatoid arthritis):
1) Define it
2) What kind of disease is it, local or systemic?
1) Chronic inflammatory disease characterized by symmetric polyarthritis
2) Systemic disease that may have extraarticular manifestations
RA (rheumatoid arthritis) labs:
1) RF and Anti-CCP antibodies are positive in _____-_____% with est. RA.
2) Antinuclear antibodies (~____%). and anemia of chronic disease may be seen.
3) __________ and __________ may be elevated; ________ may be normal, slightly elevated, or low.
4) Platelet count is often ________ and joint fluid exam consistent with inflammatory arthritis.
1) 70-80%
Other lab abnormalities may include:
2) (~20%)
3) SR and CRP; WBC
4) high
1) Antibodies directed against the Fc portion of IgG are called what?
2) Which of these is the most commonly measured?
3) What is the reference value for these?
1) Rheumatoid Factors (RFs)
2) IgM RF
3) Negative (or “very low”)
1) In Rheumatoid Arthritis, RFs react to abnormal synovial IgGs, which are produced from _______________ in joint synovial membranes and act as ____________.
2) What do RFs form when they react with these IgGs? What do these do?
1) lymphocytes; antigens
2) Immune complexes; activate the complement system and cause inflammation > joint damage
-can also damage other tissues (lung, heart, nerves, vessels, etc.)
Immune complexes that activate the complement system and cause inflammation joint damage may be formed by what?
RFs (rheumatoid factors) reacting to abnormal synovial IgGs
RF for diagnosis of RA: Describe the specificity
1) Lacks specificity for RA (false positives)
a) Found in other chronic inflammatory diseases (SLE, Sjögren’s, etc.) and chronic infections (Hep. B/C, syphilis, TB, etc.) and may be falsely positive in the elderly
b) The higher the RF level, the more likely it is to be due to RA
RF for diagnosis of RA: Describe the sensitivity
1) Limited sensitivity (false negatives)
a) Serum IgM RF present in ~75% of patients with RA
b) Sensitivity of only 50% in early disease
2) Negative RF value does not exclude RA
RF value is a It is a poor RA screening test for who?
The asymptomatic general population
(use in the appropriate clinical context and in conjunction with other findings)
Anti-Cyclic Citrullinated Peptide (anti-CCP) Antibody
(aka, CCP-IgG, anticitrullinated protein antibody (ACPA))
1) Define Citrullination. What is it a part of?
2) When does this process increase?
3) Sometimes citrullination alters peptide shape enough that the body thinks it is an antigen; what happens in that cause?
1) Posttranslational modification of protein, conversion of AA arginine to citrulline; part of apoptosis
2) During inflammation
3) Anti-CCP antibody is an IgG antibody that attacks citrullinated peptide antigens
Anti-CCP Antibodies for diagnosis of RA:
1) Sensitivity?
2) Specificity?
3) Is this always a solo test?
1) Sensitivity similar to RF
2) The most specific blood test for RA (specificity ~95%):
positive test helps rule in RA
3) Often done alongside RF
Systemic Lupus Erythematosus (SLE):
1) What is it? What organ does it affect?
2) Immunologic abnormalities, especially the production of ____________________, are a prominent feature.
3) Describe the variation of clinical features
1) Chronic autoimmune disease of unknown cause; can affect virtually any organ
2) antinuclear antibodies (ANΑ)
3) Range from mild joint and skin involvement to life-threatening kidney, hematologic, or central nervous system involvement
SLE
1) What are the sensitivity and specificity of ANA (generic)?
2) What about for specific types of ANAs, like antibodies to double-stranded DNA (anti-dsDNA) and to Smith
(anti-Sm)?
1) Very sensitive but not specific
2) Specific (but not sensitive)
SLE: Besides ANAs, what other lab values may be abnormal?
1) Depressed serum complement (flares)
2) Other autoantibodies
3) Elevated ESR +/- CRP (flares)
4) Anemia, leukopenia, thrombocytopenia
1) What are ANAs?
2) How can they be tested?
3) What is the normal range?
1) Diverse group of autoantibodies that target nuclear and cytoplasmic antigens
2) Generically or specifically for one of many subtypes using ANA panel
3) Negative
Antinuclear Antibodies (ANAs) are especially important for ________________________
systemic lupus erythematosus (SLE)
