Serology and Lab Testing in Rheumatic Diseases Flashcards
What are important acute phase reactants - immediate responses to inflammation?
- ESR (erythrocyte sedimentation rate)
- CRP (c-reactive protein)
What is ESR?
- ↑↑↑ with ____, highest in ______
- Acute inflammatory marker used to monitor the activity of a disease, especially PMR (polymyalgia rheumatica) and GCA (giant cell arteritis)
- ↑↑↑ with age, highest in women
What is CRP (C-reactive protein)?
- What ↑↑↑ CRP?
Acute phase reactant used to assess disease activity that is made in the liver that promotes opsonization of pathogens and ↑↑↑ the capacity of MO to phagocytose.
- Proinflammatory cytokines = ↑↑↑ CRP
_____ mg/l of CRP = inflammatory
How do the levels compare to ESR?
8 mg/L of CRP = inflammatory
Rise and fall quicker than ESR
Levels of what else ↑↑↑ with inflammation?
- Leukocytosis
- Thrombocytosis
- Ferritin
- Fibrinogen
- Complement
When immune complexes mediate consumption, what happens to compliment levels?
↓↓↓ C3 and C4
Between ESR and CRP, which rises and falls quicker?
CRP
What is Rheumatoid Factor (RF)
IgM autoAB made by B-cells in synovial joints of RA patients that targets the Fc portion of IgG (can be any Ig, but IgM is MC)
In which type of RA will rheumatoid factor (RF) be present 100% of the time?
“Nodular” RA
Rheumatoid Factor (RF) can positive in which conditions?
- Healthy pt’s (1-4%) and 20% of pt’s >60 y/o
- Sjogrens syndrome (95%) and SLE
- Cryoglobulinemia (40-100%)
- Primary biliary cirrhosis (70%)
- Sarcoidosis, malignancy, and lung disease
- Mixed CT diseases
How does the the levels of Rheumatoid Factor (RF) correlate with a disease process?
↑↑↑ levels = aggressive dz, joint erosions, and worse prognosis
(+) RF = ___
Depends on laboratory method;
- ELISA: (+) RF >45 IU/ml
- Latex fixation: (+) RF > 1:80
Does (+) RF = RA?
No, 20-30% of patients with RA are RF (-)
What is Anti-CCP?
Anti‐cycliccitrullinated peptide(anti‐CCP) = AB to citrullinated proteins that are associated with an aggressive, erosive disease
How does the prescence of Anti-CCP compare to (+) RF in patients with RA?
Anti-CCP = Present in 70% of patients with early RA
Anti- CCP = more specific than than RF for RA: (96%specificity; 78%sensitivity)
Anti-CCP + (+) RF= 99.5% specificity for RA
What markers are 99.5% specific for RA?
Anti-CCP plus (+) RF
Anti-DS DNA Ab is seen in 50% of what?
SLE
When do you see a homogenous pattern of ANA with ABs to histone?
>95% Drug Induced Lupus
When do you see a rim pattern of ANA with anti-dsDNA ab?
50% SLE
When do you see a speckled pattern of ANA with anti-SM (smith) ab?
Lupus
When do you see a speckled pattern of ANA with anti-SS-A/SS-B ab?
Sjrogen syndrome
When do you see a anti-centromere AB of ANA?
Scleroderma CREST/PSS
When do you see a anti-scl 70 AB of ANA?
PSS/CREST
Characteristics for SLE
- Malar rash: Erythema, malar eminence spare nasolabial folds(butterfly rash)
- Discoid rash: Erythematous patches
- Photosensitivity: Rash due to sunlight
- Oral ulcers: painless
- Arthritis: MC in 2or more peripheral joints, tender, swelling/effusion; nonerosive arthritis
- Serositis: Pleuritis, rub or plerual effusion or pericarditis, ECGchanges
