1 Rheum Labs Flashcards

1
Q

How might a patient with SLE present?

A

Woman with Fatigue x 6 months

Intermittent pain and swelling BL hand/fingers and knees x 3-4 months

Occasional sharp chest discomfort with a deep breath

Redness on cheeks

Fingers change colors and become painful when she goes to frozen section of store

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

ACR criteria for SLE Dx

A

(4 or more of the following)
Malar rash
Photosensitivity
Polyarthritis
Renal disorders (proteinuria, cellular casts)
Hematologic disorders (anemia, leukopenia, thrombocytopenia)
(+) Anti-DNA (+) anti-SM, (+) antiphospholipid Ab
Discoid rash
Mucosal ulcers
Serosa this (pleuritic or pericarditis)
Neurological disorders (HA, seizures, etc)
(+) ANA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

General lab work results for SLE

A

CBC: Anemia, Leukopenia, and/or Thrombocytopenia

Serum creatinine: elevated with renal dysfunction

U/A: hematuria, proteinuria, cellular casts

LFTs

ESR/CRP: elevated with inflammation

C3 and C4: Low complement levels indicate active lupus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the relationship between ANA and SLE?

A

(+) in >95%

Cardinal feature BUT NOT SPECIFIC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

ANA is reported in what 2 parts?

A

Titer of antibodies with serial dilution (ie 1:40)

Staining pattern of antibodies (homogenous, speckled, nucleoli, centromere)
• Loosely associated with underlying autoimmune disease - not specific

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Following a positive ANA in suspected SLE cases, what should you order?

A

Anti-dsDNA antibodies

Anti-Sm (anti-Smith) antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Antibody that is useful for distinguishing patients with SLE because it is rarely found in other disorders

A

Anti-dsDNA

Useful in clinical management too b/c often fluctuates with SLE disease activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Antibody that is detected in 10-50% of SLE patients and generally remains positive, even in remission

A

Anti-Sm antibody

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are antiphospholipid antibodies?

A

Anticardiolipin Ab, Beta 2 glycoprotein Ab, Lupus anticoagulant

Present in patients with antiphospholipid syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is antiphospholipid syndrome?

A

Primary condition OR in the setting of an underlying disease, usually SLE

Arterial, venous thromboembolic events and RECURRENT FETAL LOSS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How might a patient with Rheumatoid Arthritis present?

A

40 yo woman with fatigue x 6 months

Intermittent aching and occasional redness and swelling in hands, fingers, and knees x 3-4 months

MORNING STIFFNESS that lasts about 2 hours. Tylenol no help. Ibuprofen minimal help.

No myalgia/weakness

Mild erythema and soft tissue swelling of the PIP and MCP BUT DIPs SPARED

ULNAR DEVIATION at MCPs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Lab results you might see in a patient with RA

A

ESR: 62 mm/hr (normal <20)

CRP: 4.0 mg/dL (normal 1.0)

CBC w diff: normal except MILD thrombocytosis

ANA: positive at 1:80 with immunofluorescent-stained speckled pattern

Serum uric acid: 3.4 mg/dL (normal)

RF: can be positive OR negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Test with moderate specificity for RA

A

Rheumatoid Factor

Associated with several autoimmune/rheumatologist and non-rheumatic diseases, so need to order with antiCCP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Rheumatic diseases associated with Rheumatoid Factor

A
RA
Sjogren syndrome
Mixed connective tissue disease
SLE
Polymyositis or Dermatomyositis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Non rheumatic diseases associated with RF

A
Bacterial endocarditis
Hep B or C
TB
Sarcoidosis
Malignancy
Primary biliary cholangitis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What lab is helpful to support dx of RA and is recommended to be ordered together with RF?

A

Anti-CCP

Testing for antibodies to citrullinated peptides (ACPA) - antibodies against cyclic citrullinated peptides is the most commonly used assay

Specificity for RA is HIGH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How might Sjogren Syndrome present?

A

49 YO female with fatigue x 6 months

Dry mouth and dry eyes

Recent cavities

Joints and muscles ache diffusely

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What labs should you order for Sjogren?

A

Anti-Ro/SSA
Anti-La/SSB
ANA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

ANA is positive for 95% of Sjogren patients. What can you order with it to be more specific for Sjogren?

A

Anti-Ro/SSA and Anti-La/SSB

Generally 60-80% of patients with primary Sjogren syndrome exhibit one or both of these antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How does polymyalgia rheumatica typically present?

A

82 yo female with fatigue

Recent onset of aching pain in upper arms, low back, hips, thighs (makes it hard to brush hair)

Morning stiffness for over an hour and with long car rides

Active shoulder ROM decreased bilaterally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What non-specific inflammatory markers should you order if suspecting polymyalgia rheumatica?

A

ESR/CRP

Characteristic finding in PMR is elevated ESR and/or CRP

Associated with giant cell temporal arteritis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How would fibromyalgia present?

A

31 yo female with fatigue x 6 months

“Hurt all over” - myalgia and arthralgia

Sleeps 10 hours but wakes up still exhausted

Mind feels “foggy”

PE normal except for multiple tender points

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What would you expect lab report to show in fibromyalgia patients?

A

NORMAL (CBC, ANA, RF, CRP, ESR)

24
Q

How would you expect ankylosing spondylitis to present?

A

32 yo male with fatigue x 6 months

Ongoing low back pain and progressive stiffness

Symptoms worse in morning

LBP improves with exercise but worse with inactivity

Hx of plantar fasciitis

25
Q

What would imaging reveal in ankylosing spondylitis patients?

A

Bamboo spine

Sacroiliitis

26
Q

What lab is characteristically abnormal in ankylosing spondylitis?

A

Human Leukocyte Antigen (HLA)-B27

Seen in other spondyloarthropathies as well (Reactive arthritis, psoriatic arthritis, arthritis/spondylitis associated with IBD)

27
Q

How does scleroderma present?

A

51 yo female with fatigue x 6 months

Thickening and tightening of the skin on hands/face

Food sometimes more difficult to swallow

Pain in fingers when they get cold

Multiple telangiectasias on skin

28
Q

What are the CREST symptoms for scleroderma?

A
Calvin Osi’s
Reynaud syndrome
Esophageal involvement
Sclerodactyly
Telangiectasias
29
Q

What test is used to support the diagnosis of CREST syndrome (limited Systemic Sclerosis - scleroderma)?

A

Anticentromere Antibodies (ACA)

Found in a high percentage of patients with limited SSc/CREST

ANA will also be positive in 95% of patients

30
Q

Antibodies specific to Systemic Sclerosis

A

Anti-Scl-70 antibody (Scleroderma antibody)

Aka Antitopoisomerase I antibody

31
Q

Which test is generally associated with diffuse cutaneous systemic sclerosis and a higher risk of severe interstitial lung disease?

A

Anti-Scl-70 antibody

“70x worse” than limited Systemic Sclerosis

Absence of antibody does not exclude the diagnosis of scleroderma

32
Q

What does normal synovial fluid look like?

A

Viscous fluid, egg white consistency

Role is to reduce friction between articulate cartilage of synovial joints

33
Q

Aspiration of fluid from synovial joints is called…

A

Arthrocentesis

Important when evaluating patients with effusion or signs suggesting inflammation within the joint

34
Q

Arthrocentesis is both…

A

Therapeutic and Diagnostic

Helpful for diagnosis, relief of pressure, and injection of medications

Most injections consist of a glucocorticoid, local anesthetic, or a combo of the two

35
Q

Indications for arthrocentesis

A

New-onset acute mono arthritis
Suspected crystal-induced arthritis (gout, pseudogout)
Suspected infection/septic arthritis
Inflammatory vs noinflammatory arthritides
Unexplained joint, bursa, or tendon sheath swelling

36
Q

Common sites for arthrocentesis

A
Shoulder 
Elbow
Hip
Knee
Wrist 
Ankle
37
Q

Most feared complication of arthrocentesis?

A

Septic joint

Can occur with or w/o glucocorticoid injection

1 in 3000

38
Q

Risks associated with glucocorticoid injection

A

Tendon rupture
Nerve damage
Osteonecrosis (ischemic or avascular necrosis of bone)

Minor: skin atrophy, hypopigmentation

39
Q

Routine analysis of synovial fluid includes:

A

Gross inspection (clarity, color, viscosity)

Microscopic assessment (gram stain/culture, cell count, crystal detection)

40
Q

Characteristics of normal synovial fluid

A

Highly viscous
Clear
Essentially acellular

41
Q

What are the four categories of joint effusions

A

Noninflammatory
Inflammatory
Septic
Hemorrhagic

42
Q

What are examples of noninflammatory joint effusions?

A

OA
Trauma
Avascular necrosis

43
Q

What are examples of inflammatory joint effusions?

A
Septic arthritis
RA
Spondyloarthritis
Lyme
Crystal-induced monoarthritis (gout, pseudogout)
44
Q

What are some examples of septic joint effusions?

A

Bacterial
Fungal
Mycobacterial

45
Q

What are some examples of hemorrhagic joint effusions

A

Hemophilia
Trauma (w/ or w/o fx)
Tumor (malignant or benign)
Anticoagulation

46
Q

What is the WBC cutoff for inflammatory v noninflammatory?

A

> 2000 WBC = inflammatory

< 2000 WBC = noninflammatory

47
Q

What would the WBC count look like with septic joint effusions?

A

> 20,000

Usually > 100,000**

48
Q

Is septic arthritis possible if WBC < 100,000?

A

YES

100,000 WBC/mm3 is septic until proven otherwise

No specific WBC cut-off for septic arthritis but the likelihood of septic arthritis increases as synovial fluid WBC count increases

49
Q

Using WBC differential to determine if joint effusion is noninflammatory or septic

A

<25% neutrophils (PMNs) —> noninflammatory

≥75% neutrophils (PMNs) —> septic

50
Q

Arthrocentesis results:

Turbid, WBC - 88,000 with 90% neutrophils; crystal exam negative; gram stain of fluid shows clusters of gm(+) cocci

A

Septic arthritis

51
Q

Septic arthritis is an _______ condition

A

Urgent

Dx should be made promptly and treatment delivered efficiently to avoid further joint destruction

52
Q

How might gout present?

A

Woke up in morning with severe pain in base of L first toe after an evening out (prime rib, cocktails, dancing)

53
Q

Microscopic assessment of synovial fluid in gout would show…

A

Monosodium urate crystals

NEGATIVELY birefringent
NEEDLE shaped

54
Q

How would pseudogout present?

A

Left knee pain, swelling, redness x 2 days. No fever.

X-ray shows chondrocalcinosis

55
Q

What would arthrocentesis show in pseudogout?

A

Calcium pyrophosphate dehydrate (CPPD)

POSITIVELY birefringent
RHOMBOID shape

56
Q

What is birefringence?

A

Polarized light microscopy that is the gold standard for evaluating crystals

Determined by using a microscope with polarizing filters and red quartz compensator

Birefringence refers to a particular material’s ability to refract light rays

57
Q

Negatively birefringent crystals appear ______, while positively birefringent crystals appear _______.

A

Yellow

Blue