Rheumatology (autoimmune diseases, arthritis) US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Rheumatology (autoimmune diseases, arthritis). These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Rheumatology (autoimmune diseases, arthritis) US Medical PG Question 1: A 47-year-old woman comes to the physician because of body aches for the past 9 months. She also has stiffness of the shoulders and knees that is worse in the morning and tingling in the upper extremities. Examination shows marked tenderness over the posterior neck, bilateral mid trapezius, and medial aspect of the left knee. A complete blood count and erythrocyte sedimentation rate are within the reference ranges. Which of the following is the most likely diagnosis?
- A. Systemic lupus erythematosus
- B. Fibromyalgia (Correct Answer)
- C. Rheumatoid arthritis
- D. Polymyositis
- E. Major depressive disorder
Rheumatology (autoimmune diseases, arthritis) Explanation: ***Fibromyalgia***
- The patient's presentation of widespread **body aches for 9 months**, morning **stiffness**, and **multiple tender points** (posterior neck, bilateral mid trapezius, medial aspect of the knee) in the absence of inflammatory markers (normal ESR, normal CBC) is highly characteristic of **fibromyalgia**.
- **Paresthesias** (tingling in the upper extremities) are a common associated feature in fibromyalgia.
- Fibromyalgia is a chronic pain syndrome diagnosed clinically based on widespread pain and tender points, with normal laboratory findings.
*Systemic lupus erythematosus*
- SLE typically presents with **systemic inflammation**, often involving joints, skin, and kidneys, along with abnormalities in inflammatory markers (e.g., elevated ESR, positive ANA, cytopenias).
- The widespread tender points and completely normal inflammatory markers make SLE very unlikely.
*Rheumatoid arthritis*
- RA primarily affects the **synovial joints** symmetrically, leading to joint swelling, warmth, and morning stiffness, typically accompanied by elevated ESR and CRP.
- The examination findings show specific **tender points** rather than objective joint swelling, and the normal ESR rules against active RA.
*Polymyositis*
- Polymyositis is characterized by **proximal muscle weakness** (not diffuse body aches) and is associated with elevated muscle enzymes (CK, aldolase) and inflammatory changes on muscle biopsy.
- This patient has pain and tenderness without weakness, and her laboratory tests are normal.
*Major depressive disorder*
- While **fatigue**, body aches, and sleep disturbances can be symptoms of major depressive disorder, the presence of specific, well-defined **tender points on examination** points towards a primary pain syndrome.
- Fibromyalgia often coexists with depression, but the objective physical findings of multiple tender points are more consistent with fibromyalgia as the primary diagnosis.
Rheumatology (autoimmune diseases, arthritis) US Medical PG Question 2: A 71-year-old man presents to the clinic with complaints of right wrist pain for 2 days. On examination, redness and swelling were noted on the dorsal aspect of his right wrist. He had pain with extreme range of motion of the wrist. His history includes 2 hip replacements, 2 previous episodes of gout in both first metatarsophalangeal joints, and hypertension. Two days later, the swelling had increased in the dorsal aspect of his right wrist and hand. Wrist flexion was limited to 80% with severe pain. The pain was present on palpation of the scaphoid bone. Due to the suspicion of fracture, the patient was referred to his general practitioner for radiographs. These findings were consistent with gouty arthritis. What is the most likely cytokine involved in this process?
- A. INFγ
- B. IL-4
- C. IL-10
- D. IL-5
- E. IL-1 (Correct Answer)
Rheumatology (autoimmune diseases, arthritis) Explanation: ***IL-1***
- Interleukin-1 (IL-1) is a crucial **pro-inflammatory cytokine** highly implicated in the pathogenesis of gout. **Monosodium urate (MSU) crystals** activate the **NLRP3 inflammasome**, leading to the production of active IL-1β, which drives the inflammatory response seen in acute gout.
- The symptoms of acute gout, including severe pain, redness, and swelling, are largely mediated by IL-1, as evidenced by the effectiveness of **IL-1 inhibitors** in treating acute gout attacks.
*INFγ*
- **Interferon-gamma (IFN-γ)** is primarily associated with **Th1-mediated immune responses** and cellular immunity, often involved in antiviral and anti-tumor responses.
- While it has immunomodulatory effects, it is not the primary cytokine driving the acute inflammatory response in gout.
*IL-4*
- **Interleukin-4 (IL-4)** is a key cytokine in **Th2-mediated immune responses**, promoting **B cell activation** and **IgE production**, and is primarily involved in allergic reactions and anti-parasitic immunity.
- IL-4 generally has **anti-inflammatory effects** regarding acute crystal-induced inflammation and would not be the main driver of the symptoms described.
*IL-10*
- **Interleukin-10 (IL-10)** is a potent **anti-inflammatory cytokine** that plays a critical role in limiting the immune response and preventing tissue damage.
- IL-10 would actively suppress the inflammation seen in gout, rather than contribute to it.
*IL-5*
- **Interleukin-5 (IL-5)** is primarily involved in the growth and differentiation of **eosinophils** and is important in **allergic reactions** and defense against parasites.
- It does not play a significant role in the acute inflammatory cascade triggered by MSU crystals in gout.
Rheumatology (autoimmune diseases, arthritis) US Medical PG Question 3: A 32-year-old man presents to the clinic with a dull low back pain radiating to the buttocks. He first noted it about 2 years ago and it has progressed since then. He notes that it is worse in the morning and improves later in the day after physical activity. The patient also reports morning stiffness lasting up to 30 minutes and blurred vision, which started about 7 months ago. The patient's vital signs include: blood pressure 130/80 mm Hg, heart rate 88/min, respiratory rate 16/min, and temperature 36.8°C (98.2°F). Physical examination reveals tenderness over the sacroiliac joints and limitation of the lumbar spine movements in the sagittal plane. The patient's X-ray is shown in the picture below. Which of the following HLA variants is associated with this patient's condition?
- A. HLA-B27 (Correct Answer)
- B. HLA-DQ2
- C. HLA-DR3
- D. HLA-B47
- E. HLA-DR4
Rheumatology (autoimmune diseases, arthritis) Explanation: ***HLA-B27***
- The clinical presentation of **dull low back pain**, morning stiffness improving with activity, and **blurred vision** (suggestive of uveitis) points to a spondyloarthropathy, most commonly **ankylosing spondylitis**.
- **HLA-B27** is a strong genetic risk factor and is present in a high percentage of patients with ankylosing spondylitis and other spondyloarthropathies, making it the most likely associated HLA variant.
*HLA-DQ2*
- **HLA-DQ2** is primarily associated with **celiac disease**, an autoimmune disorder affecting the small intestine, and has no direct linkage to spondyloarthropathies.
- The patient's symptoms are musculoskeletal and ocular, not gastrointestinal, which rules out celiac disease.
*HLA-DR3*
- **HLA-DR3** is associated with various autoimmune conditions such as **Type 1 Diabetes**, **Graves' disease**, and **Sjogren's syndrome**, none of which align with the patient's symptoms.
- There is no known direct association between HLA-DR3 and spondyloarthropathies or uveitis.
*HLA-B47*
- **HLA-B47** is primarily associated with **21-hydroxylase deficiency**, a form of congenital adrenal hyperplasia, and it has no relevance to the patient's musculoskeletal and ocular symptoms.
- This genetic marker is not linked to inflammatory joint diseases or uveitis.
*HLA-DR4*
- **HLA-DR4** is a significant genetic marker for **rheumatoid arthritis** and certain other autoimmune disorders.
- The patient's symptoms (back pain improving with activity, sacroiliac tenderness, uveitis) are not typical for rheumatoid arthritis, which usually affects peripheral joints and worsens with activity.
Rheumatology (autoimmune diseases, arthritis) US Medical PG Question 4: A previously healthy 13-year-old girl is brought to the physician for evaluation of a 2-month history of fatigue. She reports recurrent episodes of pain in her right wrist and left knee. During this period, she has had a 4-kg (8.8-lb) weight loss. Her mother has rheumatoid arthritis. Her temperature is 38°C (100.4°F). Examination shows diffuse lymphadenopathy. Oral examination shows several painless oral ulcers. The right wrist and the left knee are swollen and tender. Laboratory studies show a hemoglobin concentration of 9.8 g/dL, a leukocyte count of 2,000/mm3, and a platelet count of 75,000/mm3. Urinalysis shows excessive protein. This patient's condition is associated with which of the following laboratory findings?
- A. Anti-citrullinated peptide antibodies
- B. Anti-dsDNA antibodies (Correct Answer)
- C. Leukocytoclastic vasculitis with IgA and C3 immune complex deposition
- D. Positive HLA-B27 test
- E. Excessive lymphoblasts
Rheumatology (autoimmune diseases, arthritis) Explanation: ***Anti-dsDNA antibodies***
- The patient presents with **fatigue, fever, weight loss, lymphadenopathy, oral ulcers**, **arthralgia/arthritis**, and **proteinuria**, along with **anemia, leukopenia, and thrombocytopenia**. This constellation of symptoms is highly suggestive of **Systemic Lupus Erythematosus (SLE)**.
- **Anti-dsDNA antibodies** are highly specific for SLE and are often associated with active disease, particularly **lupus nephritis**, which is indicated by the proteinuria.
*Anti-citrullinated peptide antibodies*
- These antibodies are highly specific for **rheumatoid arthritis (RA)**, a disease primarily affecting joints in a symmetrical pattern.
- While the patient's mother has RA, the patient's systemic symptoms (fever, weight loss, anemia, leukopenia, thrombocytopenia, proteinuria) and oral ulcers are not typical features of RA, especially in a 13-year-old.
*Leukocytoclastic vasculitis with IgA and C3 immune complex deposition*
- This finding is characteristic of **IgA vasculitis (Henoch-Schönlein Purpura)**, which typically presents with a palpable purpuric rash, arthritis, abdominal pain, and renal involvement (hematuria/proteinuria).
- The patient's presentation lacks the characteristic rash and GI symptoms, making this diagnosis less likely.
*Positive HLA-B27 test*
- A positive **HLA-B27** is associated with **spondyloarthropathies** such as ankylosing spondylitis, psoriatic arthritis, and reactive arthritis.
- These conditions primarily affect the spine and sacroiliac joints, often with enthesitis, and do not typically present with the multi-systemic features like cytopenias, oral ulcers, and significant proteinuria observed in this patient.
*Excessive lymphoblasts*
- The presence of **excessive lymphoblasts** in the bone marrow or blood is indicative of **acute lymphoblastic leukemia (ALL)**.
- Although ALL can present with fatigue, fever, weight loss, anemia, and thrombocytopenia, it is less commonly associated with oral ulcers, arthritis, and significant proteinuria. Additionally, while the patient has leukopenia (2,000/mm3), the presence of circulating lymphoblasts would be a key distinguishing feature of ALL that is not mentioned in this case.
Rheumatology (autoimmune diseases, arthritis) US Medical PG Question 5: A 39-year-old woman comes to the physician because of progressive pain and swelling of her wrists and hands for the past 2 months. Her hands are stiff in the morning; the stiffness decreases as she starts her chores. She also reports early-morning neck pain at rest for the past 3 weeks. She has no history of serious illness and takes no medications. Her sister has systemic lupus erythematosus. Vital signs are within normal limits. Examination shows bilateral swelling and tenderness of the wrists, second, third, and fourth metacarpophalangeal joints; range of motion is limited by pain. There is no vertebral tenderness. Cardiopulmonary examination shows no abnormalities. Neurologic examination shows no focal findings. Laboratory studies show:
Hemoglobin 12.8 g/dL
Leukocyte count 9,800/mm3
Erythrocyte sedimentation rate 44 mm/h
Serum
Glucose 77 mg/dL
Creatinine 1.1 mg/dL
Total bilirubin 0.7 mg/dL
Alkaline phosphatase 33 U/L
AST 14 U/L
ALT 13 U/L
Rheumatoid factor positive
Which of the following is the most appropriate next step in management?
- A. Adalimumab
- B. CT scan of the chest
- C. Measurement of anti-CCP antibodies (Correct Answer)
- D. X-ray of the cervical spine
- E. Measurement of anti-Smith antibodies
Rheumatology (autoimmune diseases, arthritis) Explanation: ***Measurement of anti-CCP antibodies***
- This patient presents with **classic rheumatoid arthritis (RA)**: symmetric polyarthritis affecting wrists and MCP joints, morning stiffness improving with activity, elevated ESR, and positive rheumatoid factor.
- **Anti-CCP (anti-cyclic citrullinated peptide) antibodies** are highly specific for RA (~95% specificity) and should be measured to **confirm the diagnosis**.
- Anti-CCP positivity helps with **prognostication** (associated with more aggressive disease and erosive changes) and guides early initiation of disease-modifying antirheumatic drugs (DMARDs) like methotrexate.
- Early diagnosis and treatment of RA is crucial to prevent irreversible joint damage and disability.
*Measurement of anti-Smith antibodies*
- **Anti-Smith antibodies** are highly specific for **systemic lupus erythematosus (SLE)**, not RA.
- This patient has **no clinical features of SLE** (no malar rash, photosensitivity, oral ulcers, serositis, renal involvement, or cytopenias).
- Family history of SLE alone does not warrant testing when the clinical presentation clearly points to RA.
- The neck pain is consistent with early RA involvement of cervical spine, not SLE.
*Adalimumab*
- **Adalimumab** is a TNF-alpha inhibitor used for RA, but it is **not first-line therapy**.
- The diagnosis must first be confirmed, and conventional DMARDs (especially **methotrexate**) should be tried first.
- Biologics like adalimumab are reserved for patients who fail conventional DMARDs or have severe disease at presentation.
*CT scan of the chest*
- There are **no respiratory symptoms** or abnormal cardiopulmonary findings on examination.
- While RA can cause interstitial lung disease or pleural effusions, screening imaging is not indicated without clinical signs or symptoms.
- The priority is confirming the diagnosis of RA.
*X-ray of the cervical spine*
- While the patient has neck pain, the **neurological examination is normal** and there is no vertebral tenderness.
- Cervical spine involvement in RA (atlantoaxial subluxation) typically occurs in longstanding disease, not at presentation.
- Imaging would be indicated if there were neurological deficits, severe pain, or mechanical symptoms suggesting instability.
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