Clinical Serology, Lab Testing, & Gout/Pseudogout Flashcards
Acute phase reactant that is a marker of inflammation
Rises with age, higher in women, and monitors disease activity
ESR
ESR is utilized to monitor disease activity, especially _____ and ______
Polymyalgia rheumatica; giant cell arteritis
CRP is an acute phase reactant that is a marker of inflammation and is utilized as an assessment of disease activity.
It is synthesized in the ______. Proinflammatory ______ increase the CRP.
CRP can also activate ______ and promote phagocytosis
A CRP reading of >8 mg/L is inflammatory
Liver; cytokines
Complement
T/F: ESR rises and falls more quickly than CRP
False; CRP rises and falls quicker than ESR
Examples of general inflammatory markers other than ESR and CRP
Leukocytosis Thrombocytosis Ferritin Fibrinogen Complement (decreases)
IgM autoantibody that targets the Fc portion of IgG immunoglobulin
Rheumatoid factor
RF is produced by _____ cells in ______ joints of RA pts
B cells; synovial
RF is present in 70% of pts with RA, and is present in 100% of pts with _______ RA
Nodular
Besides RA, what conditions might reveal a positive RF?
Sjogrens syndrome Cryoglobulinemia Primary biliary cirrhosis Mixed CT disease Endocarditis; chronic infections SLE Sarcoidosis Malignancy Lung disease
The cutoff value for positive RF depends on lab method; positive RF > 45 IU/mL by ELISA or >1:80 by latex fixation.
Higher RF levels are correlated with what features of the inflammatory disease process?
High levels associated with more aggressive disease, joint erosions, and worse px
_______ antibodies are present in 70% of pts with early RA and have more specificity characteristics of RA than RF
Anti-cyclic citrullinated peptide (anti-CCP)
______ antibodies + _____ = 99.5% specificity for RA
Anti-CCP; RF
Antibody directed against nuclear antigens; may be found in normal pts as well as those with RA, CTD, malignancy, etc. (nonspecific!!); pattern of immunofluorescence gives clues to dx
Anti-nuclear antibody (ANA)
Homogenous ANA pattern
Histone antibody — 95% of drug-induced lupus
Rim pattern of ANA
Anti-dsDNA — 50% SLE
Speckled ANA pattern
Anti-Sm (smith) — lupus
Anti-SS-A/SS-B — Sjogren
________ and _____ antibodyies are associated with scleroderma CREST/progressive systemic sclerosis
Anticentromere; anti-scl 70
Hematologic criteria/findings in SLE
Hemolytic anemia with reticulocytosis
[or]
Leukopenia (<4000/mm3 total)
[or]
Lymphopenia (<1500/mm3) on 2 or more occasions
[or]
Thrombocytopenia (<100,000/mm3)
Immunologic findings associated with lupus
Anti-DNA Abs
Anti-Sm
Antiphospholipid antibodies (IgG or IgM cardiolipin Abs)
Positive lupus anticoagulant
False positive RPR (syphilis test)
ANA
What is the significance of a positive antistreptolysin O antibody (ASO) and/or anti-DNAase B titer?
Evidence of a preceding group A streptococcal infection
[Clinically may see acute rheumatic fever, polyarticular asymmetric arthritis of large joints, may cause post-streptococcal reactive arthritis (symmetric and affects small joints)]
A 46 y/o male presents with fatigue, malaise, pain in both wrists, and bilateral swelling over MCP joints. He admits to previous hx of lupus. The symptoms have been present for 6 weeks. PE reveals decreased strength in both hands, swollen wrists, PIPs, and MCP joints bilaterally, and a nodule on the extensor surface of the left arm. Which lab test would you expect to be abnormal in this case?
A. CBC indicating hemolytic anemia, leukocytosis, and negative RPR
B. Low complement C3, decreased ferritin, and elevated platelet count
C. Positive anti-CCP, elevated ESR, and elevated RF level
D. Positive ANA, negative RF, and elevated CRP
E. Thrombocytosis, hypocalcemia, and normal ESR
C. Positive anti-CCP, elevated ESR, and elevated RF level
Hyperuricemia is defined as a uric acid > _______ mg/dL that may be due to overproduction or underexcretion of uric acid. It is associated with development of gouty arthritis which consists of ___________ crystals in joint fluid or tophi.
Crystals are needle-shaped, ______ birefringent by polarized light microscopy.
Attacks are acute in onset, monoarticular, often the 1st MTP joint (_______). Often nocturnal awakening.
6.8; monosodium urate
Negative
Podagra
Nodular deposits of monosodium urate crystals in skin
Tophi
90% of gout cases are in men (4th-6th decade) or ________ women
Post-menopausal
