Chapter 41 - Rheumatologic Disease

Question 1

Which hepatic disease has been associated with anticentromere antibodies?

Answer 1

Primary biliary cirrhosis

Question 2

Which auto-antibody is most associated with neonatal lupus?

Answer 2

Anti-Ro, but also anti-La

Question 3

Which three antibodies are most closely associated with Sjogren’s syndrome?

Answer 3

Alpha-fodrin, Ro, and La

*Alpha-fodrin auto-antibodies are more common that Ro and La auto-antibodies

Question 4

Which two auto-antibodies are most closely associated with rheumatoid arthritis?

Answer 4

Rheumatoid factor and anti-cyclic citrullinated protein (CCP) antibodies
*Anti-CCP targets citrullinated proteins in the skin (e.g. fillagrin) and joints

Question 5

What is the molecular target of rheumatoid factor?

Answer 5

Fc portion of IgG

Question 6

What symptom or sign of SLE is dsDNA autoantibody associated with (i.e. which type of organ dysfunction)?

Answer 6

Lupus nephritis

*dsDNA can also be used to monitor SLE disease activity

Question 7

Which 3 autoAb have the highest specificity for SLE?

Answer 7

Anti-dsDNA, Sm, rRNP

Question 8

What serologic marker is common amongst all AI CTDs (ie. SLE, RA, SSc, dermatomyopathy)?

Answer 8

U1RNP, which also defines the concept of mixed CTDs

Question 9

What are some drugs that can cause drug induced ANA/SLE?

Answer 9

Procainamide, hydralazine, isoniazid, chlorpromazine, phenytoin, methyldopa, minocycline, TNF-alpha inhibitors

Question 10

What are the signs and symptoms of drug induced ANA/SLE?

Answer 10

MSK (arthritis, arthralgia, myalgia), serositis (pleuritis, pericarditis), positive ANA, positive anti-dsDNA, skin findings (malar rash, SCLE, DLE, photosensitivity and purpura), phlebitis (with anticardiolipin antibodies), leukopenia, thrombocytopenia, general manifestations (fever, weight loss, asthenia)

Question 11

Does age have an effect on ANA levels?

Answer 11

Yes, up to 15% of otherwise healthy individuals of >55yo can be found to have a significantly elevated ANA titer of no apparent clinical consequence

Question 12

What type of bloodwork would you order for a patient who you SUSPECT has an AI CTD?

Answer 12

ANA. Then anti-dsDNA, anti-Sm, CBCd, Cr, albumin, total protein, ESR, U/A, C3, C4

Question 13

What pattern of nucelar immunofluorescence may be clinically significant?

Answer 13

Centromeric/discrete speckled pattern, which is specific for Ab to chromosomal centromers (CENP-B) seen in CREST sydrome

Question 14

Other than Wegener’s granulomatosis, what else may C-ANCA correlate with?

Answer 14

Cystic fibrosis, perform sweat test