Rheumatology Boards ABIM
ANA fluorescence importance - correct answer ✔✔useless except centromere staining - (limited
scleroderma (CREST), primary biliary cirrhosis)
ANA frequency in dz - correct answer ✔✔Drug induced SLE - 100%
SLE - 90%
Polymyositis/dermatomyositis - 40-60%
RA - 40%
MCTD - 95%
Limited scleroderma and diffuse scleroderma - 60-90%
Sjogrens - 70%
Nl population - 30% (1:40), 5% (1:160)
So, need more specific subtype testing if positive
ANA subtypes - correct answer ✔✔Anti-dsDNA - specific for SLE, can be + if taking TNF inhibs. Marker for
dz activity & potential for renal dz
Anti-Sm - specific for SLE, often seen with U1-RNP
Anti U1-RNP - sensitive, not specific for MCTP (neg rules it out)
Anti-histone - sens, not spec for drug induced SLE (procainamide, hydralazine, chlorpromazine,
quinidine)
Anti-Scl-70 - diffuse scleroderma, increased chance of interstitial lung dz
Anti-centromere - limited scleroderma; increased Pulm HTN
Anti-synthetase (Jo-1) - myositis; increased ILD
Anti-SSA, SSB tests - correct answer ✔✔SSA (Ro) - SLE, neonatal SLE, Sjogrens, myositis; not in
scleroderma; maternal transfer to baby - neonatal heart block
SSB (La) - SLE, Sjogrens; sometimes found with SSA; can see maternal transfer to baby
,ANCA testing - correct answer ✔✔Get p & c-ANCA. If positive, check ELISA for subtypes anti-PR3, anti-
MPO
c-ANCA + anti-PR3 - Wegeners
p-ANCA, MPO positive - Churg-Strauss, PAN, pauci-immune glomerulonephritis, microscopic polyangiitis,
anti-glomerular basement membrane dz
p-ANCA, MPO negative - Crohns, UC, chronic active hepatitis, PBC, PSC, PAN, chronic arthridities
Compliment tests - correct answer ✔✔low in active SLE, vasculitis
Can also be low from genetic deficiency, consumed with activation, or underproduced (HELLP syndrome)
C3 - consumed with any compliment activation
C4 - consumed with only classic pathway activation
CH50 - looks at total hemolytic component of classical pathway
Rheumatoid factor and anti-CCP (citrullinated cyclic peptide) - correct answer ✔✔RF - pos in 80-85% of
RA, not specific
CCP - appears earlier, greater specificity
HLA's - correct answer ✔✔HLA-B27 - 7-8% of nl population; 60-80% in Reiters + reactive
spondyloarthropathy; 90% with ank spondy; 60% of sponylitis pts with psoriasis or IBD are positive; 80%
in Yersinia, Salmonella, Shigella arthropathy
HLA-DR2, DR3 - Sjogrens, polymyositis
HLA-DR4 - severe RA
Joint fluid evaluation - correct answer ✔✔Normal - 0-200 WBC
Non-inflammatory- 200-2000 WBC - OA, neuropathic joins, hypertrophic osteoarthropathy, occasionally
SLE, scleroderma, rheumatic fever
Inflammatory - 2K-50K WBC - RA, SLE, SS, crystals, ank spon, IBD-assc arthritis
Septic - 50K+ - >75% neurophils. Occasionally see this many WBC with crystals
Crystals in joint - correct answer ✔✔Gout - yellow, negatively birefringent
CPPD - blue crystals, positively birefringent
, To be sure they are causing the inflammation, you should see them intracellularly
Collagen vascular diseases - correct answer ✔✔Marfan syndrome - long limbs, aortic root dilation,
ectopia lentis
Ehler-Danlos - skin elasticity and joint hypermobility; types - classic (most severe, easily scarred skin and
hypermobile joints), Hypermobile (mainly joint symptoms), vascular (mainly skin issues and rupture of
large vessels)
Osteogenesis imperfecta - procollagen gene defects; osteopenia, brittle bones, blue sclera, teeth
problem, hearing loss
Pseudoxanthoma elasticum - autosomal recessive; affects skin, blood vessels, eyes. Angioid steaks on
fundoscopy; recurrent GI bleeding
Prevalence of RA - correct answer ✔✔1% overall, 40-50 yo, female: male 3:1, 10% with genetics
Labs for RA - correct answer ✔✔RF - 80-85%
anti-CCP - 97%, earlier than RF; assc with erosive RA
HLA-DR4 - aggressive RA
Joint fluid - inflammatory (2K+wbc), decreased viscosity; finf IL-1, IL-6 in joint fluid
Markers for severe course in RA - correct answer ✔✔high titer RF
positive anti-CCP, HLA-DR4,
Constitutional symptoms
Insidious onset
early XR evidence of erosive dz
extraarticular dz
Diagnostic criteria for RA - correct answer ✔✔4+ of the following:
AM stiffness > 1 hr for 6 wks
Swelling of wrists, MCP, PIP x 6 wks
Swelling of 3 joints x 6 wks