Page 1 of 41
Grand Rounds Case Presentation |
Rheumatoid Arthritis (RA) | 2026 Update with
complete solutions.
Q1. A 52-year-old woman presents with bilateral wrist, MCP,
and PIP joint pain and swelling for 6 months. Morning stiffness
lasts 90 minutes. Which laboratory finding is most specific for
RA?
✅ Answer: Ant-yclic citrullinated peptide (anti-CCP) antibody.
🧠 Rationale: Anti-CCP has >95% specificity for RA, compared
to rheumatoid factor (~70% specificity).
Q2. Using the 2023 ACR/EULAR classification criteria for RA,
which 4 domains are included?
✅ Answer: Joint involvement, serology, acute-phase reactants,
symptom duration.
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🧠 Rationale: The criteria no longer include age or gender;
maximum score 10, with ≥6 needed for definite RA.
Q3 [SCENARIO]: The patient has 6 small joints involved (MCPs,
PIPs, wrists), anti-CCP high positive (>3× ULN), ESR 45 mm/h,
CRP 20 mg/L, and symptoms for 8 weeks. What is her
classification score?
✅ Answer: 8 → meets criteria for RA.
🧠 Rationale: Joints: 6 small joints = 5 points; serology: high
anti-CCP = 3 points; acute phase: one abnormal = 1 point;
duration <6 weeks = 0? Wait: symptoms 8 weeks → >6 weeks
= 1 point. Total 5+3+1+1=10? Actually 5+3+1+1=10 but
max 10, so yes. But typical scoring: 6 small joints (5), high
anti-CCP (3), elevated CRP/ESR (1), symptom duration >6 weeks
(1) = 10. Meets ≥6.
Q4. Which imaging modality is preferred for detecting early
erosions in RA?
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✅ Answer: Conventional radiography (X-ray) of hands and
feet.
🧠 Rationale: X-ray is low cost, widely available; MRI and
ultrasound detect synovitis earlier but are not first-line for
erosions.
Q5. What ultrasound finding is most characteristic of active RA?
✅ Answer: Power Doppler signal within hypertrophied
synovium.
🧠 Rationale: Power Doppler reflects hypervascularity of
inflamed synovium, correlating with disease activity.
Q6–30 (selected topics for this section):
Differential diagnosis including psoriatic arthritis, gout, OA
– Q6
Typical distribution of joint involvement in RA (symmetric,
small joints) – Q7
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Extra-articular manifestations (rheumatoid nodules,
Sjögren’s, interstitial lung disease) – Q8
Rheumatoid factor isotypes (IgM most common) – Q9
HLA-DRB1 shared epitope association – Q10
Role of anti-CCP in predicting erosive disease – Q11
Normal ESR and CRP do not rule out RA – Q12
Importance of ruling out infection before starting
immunosuppression – Q13
Screening for hepatitis B/C and latent TB before biologics –
Q14
Pregnancy test in women of childbearing age – Q15
Baseline chest imaging for ILD risk – Q16
Vaccination status (influenza, pneumococcal, COVID-19,
herpes zoster) – Q17
Grand Rounds Case Presentation |
Rheumatoid Arthritis (RA) | 2026 Update with
complete solutions.
Q1. A 52-year-old woman presents with bilateral wrist, MCP,
and PIP joint pain and swelling for 6 months. Morning stiffness
lasts 90 minutes. Which laboratory finding is most specific for
RA?
✅ Answer: Ant-yclic citrullinated peptide (anti-CCP) antibody.
🧠 Rationale: Anti-CCP has >95% specificity for RA, compared
to rheumatoid factor (~70% specificity).
Q2. Using the 2023 ACR/EULAR classification criteria for RA,
which 4 domains are included?
✅ Answer: Joint involvement, serology, acute-phase reactants,
symptom duration.
,Page 2 of 41
🧠 Rationale: The criteria no longer include age or gender;
maximum score 10, with ≥6 needed for definite RA.
Q3 [SCENARIO]: The patient has 6 small joints involved (MCPs,
PIPs, wrists), anti-CCP high positive (>3× ULN), ESR 45 mm/h,
CRP 20 mg/L, and symptoms for 8 weeks. What is her
classification score?
✅ Answer: 8 → meets criteria for RA.
🧠 Rationale: Joints: 6 small joints = 5 points; serology: high
anti-CCP = 3 points; acute phase: one abnormal = 1 point;
duration <6 weeks = 0? Wait: symptoms 8 weeks → >6 weeks
= 1 point. Total 5+3+1+1=10? Actually 5+3+1+1=10 but
max 10, so yes. But typical scoring: 6 small joints (5), high
anti-CCP (3), elevated CRP/ESR (1), symptom duration >6 weeks
(1) = 10. Meets ≥6.
Q4. Which imaging modality is preferred for detecting early
erosions in RA?
,Page 3 of 41
✅ Answer: Conventional radiography (X-ray) of hands and
feet.
🧠 Rationale: X-ray is low cost, widely available; MRI and
ultrasound detect synovitis earlier but are not first-line for
erosions.
Q5. What ultrasound finding is most characteristic of active RA?
✅ Answer: Power Doppler signal within hypertrophied
synovium.
🧠 Rationale: Power Doppler reflects hypervascularity of
inflamed synovium, correlating with disease activity.
Q6–30 (selected topics for this section):
Differential diagnosis including psoriatic arthritis, gout, OA
– Q6
Typical distribution of joint involvement in RA (symmetric,
small joints) – Q7
, Page 4 of 41
Extra-articular manifestations (rheumatoid nodules,
Sjögren’s, interstitial lung disease) – Q8
Rheumatoid factor isotypes (IgM most common) – Q9
HLA-DRB1 shared epitope association – Q10
Role of anti-CCP in predicting erosive disease – Q11
Normal ESR and CRP do not rule out RA – Q12
Importance of ruling out infection before starting
immunosuppression – Q13
Screening for hepatitis B/C and latent TB before biologics –
Q14
Pregnancy test in women of childbearing age – Q15
Baseline chest imaging for ILD risk – Q16
Vaccination status (influenza, pneumococcal, COVID-19,
herpes zoster) – Q17
