Rheumatology and Immunology — MCQs

Rheumatology and Immunology Indian Medical PG Practice Questions and MCQs

Question 861: A 45-year-old patient presents with skin thickening, Raynaud's phenomenon, and digital ulcers. Which enzyme is the target of autoantibodies in this autoimmune disorder?

A. DNA polymerase
B. Protein kinase
C. RNA polymerase II
D. Histone deacetylase (Correct Answer)

Explanation: ***Histone deacetylase*** - This clinical presentation of **skin thickening**, **Raynaud's phenomenon**, and **digital ulcers** is highly suggestive of ** системная склеродермия** (systemic sclerosis), specifically the **limited cutaneous form** [1]. - In systemic sclerosis, various autoantibodies are present, and **anti-Scl-70 antibodies** (also known as **anti-topoisomerase I**) are seen in diffuse cutaneous systemic sclerosis [2]. However, the question might refer to a less common or emerging target. For example, antibodies against **histone deacetylases (HDACs)** are being investigated for their role in fibrosis and have been found in some patients with scleroderma, influencing ECM remodeling. *DNA polymerase* - Autoantibodies against **DNA polymerase** are not typically associated with the primary diagnosis of scleroderma. - While other **DNA-binding antibodies** like anti-dsDNA are characteristic of **Systemic Lupus Erythematosus (SLE)**, they are not a hallmark of scleroderma [3]. *RNA polymerase II* - Autoantibodies to **RNA polymerase III** are characteristic of **diffuse cutaneous systemic sclerosis** and are associated with a higher risk of **scleroderma renal crisis** and **cancer**. - **RNA polymerase II** is a fundamental enzyme in gene transcription, but autoantibodies specifically targeting RNA polymerase II are not commonly diagnostic markers for scleroderma. *Protein kinase* - **Protein kinases** are involved in numerous cellular signaling pathways. While dysregulation of kinase activity is implicated in the pathogenesis of fibrosis in scleroderma, **autoantibodies directly targeting protein kinases** are not used as primary diagnostic markers for the disease in the same way as anti-centromere or anti-topoisomerase I antibodies. - Antibodies against specific kinases like **Akt** or **MAPK** have been studied in research settings but are not routinely tested or recognized as major autoantigens in scleroderma.

Question 862: A 35-year-old female with heliotrope rash and Gottron's papules has a muscle biopsy showing inflammatory myopathy. What is the diagnosis?

A. Systemic lupus erythematosus (SLE)
B. Polymyositis
C. Systemic sclerosis (SSc)
D. Dermatomyositis (Correct Answer)

Explanation: ***Dermatomyositis*** - The combination of a **heliotrope rash**, **Gottron's papules**, and **inflammatory myopathy** on muscle biopsy is pathognomonic for dermatomyositis [1], [2]. - This condition is characterized by **proximal muscle weakness** and distinctive dermatological manifestations [1], [2]. *Systemic lupus erythematosus (SLE)* - While SLE can cause a rash and myositis, the specific presentation of a **heliotrope rash** and **Gottron's papules** is not characteristic of SLE [2]. - SLE rashes typically include a **malar rash** or discoid lesions, and myositis is less common and usually milder [3]. *Polymyositis* - Polymyositis also presents with **inflammatory myopathy** and proximal muscle weakness, but it lacks the characteristic dermatological features seen in this patient [1]. - It does not involve **heliotrope rash** or **Gottron's papules** [1]. *Systemic sclerosis (SSc)* - SSc primarily affects the **skin** with thickening and hardening, and can involve internal organs, but does not typically present with the specific rash and papules described. - Muscle involvement in SSc is usually secondary to **fibrosis** or vasculopathy, distinct from the inflammatory myopathy of dermatomyositis.

Question 863: A 40-year-old female presents with a chronic dry cough and progressive dyspnea. A CT scan shows diffuse interstitial infiltrates, and pulmonary function tests indicate a restrictive pattern. Serology is positive for anti-SSA/Ro antibodies. What is the most likely diagnosis?

A. Systemic sclerosis
B. Rheumatoid arthritis
C. Sjögren's syndrome (Correct Answer)
D. Systemic lupus erythematosus

Explanation: ***Sjögren's syndrome*** - The presentation of **diffuse interstitial infiltrates** and **restrictive pulmonary function tests**, along with a **positive anti-SSA/Ro antibody**, strongly suggests Sjögren's syndrome, which can affect the lungs [1]. - While commonly associated with sicca symptoms (**dry eyes** and **mouth**), Sjögren's can also manifest as significant **extraglandular involvement**, including interstitial lung disease [2]. *Systemic sclerosis* - Although systemic sclerosis can cause **interstitial lung disease** and restrictive lung patterns, the primary serological marker in this case is **anti-SSA/Ro**, which is not typical for systemic sclerosis [2]. - Characteristic findings for systemic sclerosis usually include skin thickening and specific antibodies like **anti-Scl-70** or **anti-centromere antibodies**. [2] *Rheumatoid arthritis* - **Rheumatoid arthritis** can cause interstitial lung disease, but a positive **anti-SSA/Ro antibody** is not a primary diagnostic marker for RA; **rheumatoid factor** and **anti-CCP antibodies** are more characteristic [2]. - While RA can present with cough and dyspnea stemming from lung involvement, the serological profile points elsewhere. *Systemic lupus erythematosus* - While **anti-SSA/Ro antibodies** can be positive in **Systemic Lupus Erythematosus (SLE)**, the primary manifestation often involves other organ systems like kidneys, joints, and skin, with lung involvement being variable [2]. - Although SLE can cause pleurisy or lupus pneumonitis, **diffuse interstitial infiltrates** leading to restrictive patterns, combined with anti-SSA/Ro positivity, are more classically associated with Sjögren's syndrome as a **primary manifestation**.

Question 864: Ankylosing spondylitis most commonly affects which region of the spine?

A. Cervical spine
B. Thoracic spine
C. Lumbar spine
D. Sacroiliac joints (Correct Answer)

Explanation: ***Sacroiliac joints*** - Ankylosing spondylitis characteristically begins with inflammation of the **sacroiliac joints**, leading to **sacroiliitis** [1]. - This involvement is often **bilateral** and symmetrical, serving as a hallmark feature for diagnosis. *Cervical spine* - While the cervical spine can eventually be affected in later stages of ankylosing spondylitis, it is typically **not the initial or most common site** of involvement. - Involvement here can lead to neck stiffness and reduced range of motion, but usually **after** sacroiliac and lumbar spine disease. *Thoracic spine* - The thoracic spine may become involved in the progression of ankylosing spondylitis, contributing to the characteristic **"bamboo spine"** appearance. - However, it is **less commonly the primary site** of disease onset compared to the sacroiliac joints. *Lumbar spine* - The lumbar spine is frequently affected **after the sacroiliac joints**, leading to inflammation, stiffness, and eventual fusion [1]. - However, the **sacroiliiac joints are almost universally involved first** or concurrently, making them the most common initial presentation.

Question 865: A 60-year-old woman with rheumatoid arthritis presents with severe pain and swelling in her right knee. Arthrocentesis reveals cloudy fluid with a high white blood cell count. What is the most likely diagnosis?

A. Gout
B. Pseudogout
C. Septic arthritis (Correct Answer)
D. Osteoarthritis

Explanation: ***Septic arthritis*** - The combination of **rheumatoid arthritis (RA)**, a severe inflammatory condition, with acute **monoarticular pain and swelling**, along with **cloudy synovial fluid** and a **high WBC count on arthrocentesis**, strongly suggests septic arthritis [1]. - Patients with RA are at **increased risk for septic arthritis** due to compromised immune systems from the disease itself and immunosuppressive medications [3]. *Gout* - While gout presents with acute inflammatory arthritis, it typically involves **negatively birefringent, needle-shaped crystals** of **monosodium urate** in the synovial fluid. - The synovial fluid in this case is described as cloudy with a high WBC count, requiring further crystal analysis to confirm gout, but **infection is a more pressing concern** given the RA history. *Pseudogout* - Pseudogout, caused by **calcium pyrophosphate dihydrate (CPPD) crystals**, would show **positively birefringent, rhomboid-shaped crystals** in the synovial fluid [2]. - Like gout, it is an inflammatory arthritis, but the primary concern with a high WBC count and RA history is ruling out bacterial infection. *Osteoarthritis* - Osteoarthritis typically causes **chronic, progressive joint pain** and is associated with **clear to mildly cloudy synovial fluid** with a **low WBC count** (<2000 cells/mm³). - The acute, severe symptoms and high WBC count are inconsistent with uncomplicated osteoarthritis [2].

Question 866: A 54-year-old woman presents with proximal muscle weakness and a skin rash over her knuckles. Laboratory tests show elevated muscle enzymes and a positive anti-Jo-1 antibody. What is the most likely diagnosis?

A. Dermatomyositis (Correct Answer)
B. Rheumatoid arthritis
C. Systemic lupus erythematosus
D. Scleroderma

Explanation: Dermatomyositis - The classic triad of **proximal muscle weakness**, a characteristic **skin rash over the knuckles** (Gottron's papules), and **elevated muscle enzymes** strongly indicates dermatomyositis [1]. - The presence of **anti-Jo-1 antibody** further supports the diagnosis, as this is an autoantibody specifically associated with dermatomyositis and polymyositis, particularly with interstitial lung disease [1, 2]. *Rheumatoid arthritis* - Primarily characterized by **symmetric polyarthritis** affecting small joints, not proximal muscle weakness. - While elevated inflammatory markers can be present, **muscle enzymes are typically normal**, and the rash over the knuckles is not typical [2]. *Systemic lupus erythematosus* - Can cause a wide range of symptoms including muscle pain and skin rashes (e.g., malar rash), but **proximal muscle weakness with elevated muscle enzymes** is not its primary presentation. - Specific autoantibodies like **anti-dsDNA** or **anti-Sm** are characteristic, rather than anti-Jo-1 [2]. *Scleroderma* - Characterized by **skin thickening** and **fibrosis of internal organs**, which are not described in this patient [3]. - While muscle involvement can occur, it's typically not the predominant feature, and the specific rash and anti-Jo-1 antibody are not indicative of scleroderma.

Question 867: Which of the following is NOT a typical feature of seropositive rheumatoid arthritis?

A. Inflammation in multiple joints
B. Symmetrical joint involvement
C. Joint pain and swelling
D. Asymmetrical joint involvement (Correct Answer)

Explanation: ***Asymmetrical joint involvement*** - **Seropositive rheumatoid arthritis** typically presents with **symmetrical polyarthritis**, meaning that joints on both sides of the body are affected similarly [1]. - While some asymmetry can occur in early stages or with atypical presentations, it is not considered a **typical feature** of established rheumatoid arthritis [1]. *Inflammation in multiple joints* - **Polyarthritis**, or inflammation in multiple joints, is a hallmark of rheumatoid arthritis, distinguishing it from **mono-** or **oligoarthritis** [1], [2]. - This widespread involvement contributes to the systemic nature and disability associated with the disease. *Symmetrical joint involvement* - **Symmetry** in joint involvement is a classic and highly characteristic feature of rheumatoid arthritis, often affecting the same joints on both sides of the body [1]. - This symmetrical pattern helps differentiate rheumatoid arthritis from other forms of **inflammatory arthritis** that tend to be unilateral or asymmetrical [1]. *Joint pain and swelling* - **Joint pain** and **swelling** are among the most common and typical symptoms of active rheumatoid arthritis, reflecting the underlying inflammatory process [1]. - These symptoms are often accompanied by **morning stiffness** lasting more than 30 minutes, which resolves with activity [1].

Question 868: All are true about Marie-Strumpell disease except which of the following?

A. Enhesitis is common
B. Most commonly involves the sacro - iliac joints
C. More common in males
D. Roentgenogram is the most sensitive investigation for Marie-Strumpell disease. (Correct Answer)

Explanation: ***Roentgenogram is the most sensitive investigation for Marie-Strumpell disease.*** - While X-rays can show characteristic changes in advanced Marie-Strumpell disease (ankylosing spondylitis), **Magnetic Resonance Imaging (MRI)** of the sacroiliac joints is the most sensitive imaging modality for detecting early inflammatory changes like **bone marrow edema** [1]. - **Roentgenograms (X-rays)** are less sensitive in the early stages and may only show changes after significant structural damage has occurred [1]. *Most commonly involves the sacro - iliac joints* - Marie-Strumpell disease, also known as **ankylosing spondylitis**, is characterized by inflammation and eventual fusion of the **sacroiliac joints** and the spine [1]. - Involvement typically begins in the sacroiliac joints and progresses upwards along the vertebral column. *Enhesitis is common* - **Enthesitis**, which is the inflammation at the sites where tendons or ligaments attach to bone, is a hallmark feature of Marie-Strumpell disease [1]. - Common sites for enthesitis include the **Achilles tendon insertion**, plantar fascia, and costochondral junctions. *More common in males* - Marie-Strumpell disease (ankylosing spondylitis) has a higher prevalence and often a **more severe course in males** compared to females. - The male-to-female ratio is estimated to be around 2-3:1, although milder cases in women may be underdiagnosed.

Question 869: Patients with which of the following conditions are at greatest risk of pernio

A. Raynaud's phenomenon (Correct Answer)
B. Kawasaki disease
C. Hepatitis C infection
D. Henoch-Schönlein purpura

Explanation: ***Raynaud's phenomenon*** - Patients with **Raynaud's phenomenon** have an underlying **vasospastic disorder** where small arteries, especially in the fingers and toes, constrict in response to cold or stress. - This predisposition to **vasoconstriction** makes them more susceptible to developing pernio (chilblains), which is also a localized inflammatory lesion triggered by exposure to cold in susceptible individuals. *Kawasaki disease* - **Kawasaki disease** is a form of **vasculitis** primarily affecting children, characterized by fever, rash, conjunctivitis, and changes in the oral mucosa and extremities. [1] - While it affects blood vessels, its pathology and clinical manifestations are distinct from pernio, and it does not predispose individuals to chilblains. *Henoch-Schönlein purpura* - **Henoch-Schönlein purpura** (HSP) is a **small-vessel vasculitis** characterized by a classic tetrad of palpable purpura, arthritis, abdominal pain, and renal disease, predominantly affecting children. [1] - The mechanism of HSP involves IgA deposition in vessel walls and is not associated with an increased risk of pernio. *Hepatitis C infection* - **Hepatitis C infection** is a viral infection that primarily affects the liver but can have various **extrahepatic manifestations**, including mixed cryoglobulinemia, which causes vasculitis. [1] - While cryoglobulinemic vasculitis can lead to skin lesions, it is distinct from pernio, and hepatitis C infection itself does not directly increase the risk of developing pernio.

Question 870: Which condition is characterized by the triad of skin lesions, mononeuritis multiplex, and elevated eosinophils?

A. Alports syndrome
B. Wegeners granulomatosus
C. Churg - Strauss syndrome (Correct Answer)
D. Cryoglobulinemia

Explanation: ***Churg - Strauss syndrome*** - **Churg-Strauss syndrome** (now known as **Eosinophilic Granulomatosis with Polyangiitis, EGPA**) is characterized by the triad of **skin lesions**, **mononeuritis multiplex** (nerve damage), and **elevated eosinophils** [1]. - It is a **small-vessel vasculitis** with a strong association with **asthma** and **allergic rhinitis** [1]. *Alports syndrome* - **Alport syndrome** is an inherited disorder affecting **type IV collagen**, primarily manifesting as **glomerulonephritis**, **sensorineural hearing loss**, and **ocular abnormalities**. - It does not present with skin lesions, mononeuritis multiplex, or eosinophilia. *Wegeners granulomatosus* - **Wegener's granulomatosis** (now **Granulomatosis with Polyangiitis, GPA**) is characterized by **granulomatous inflammation** of the upper and lower respiratory tracts, **glomerulonephritis**, and **systemic vasculitis** [2]. - While it can cause skin lesions and neuropathy, it is typically associated with **antineutrophil cytoplasmic antibodies (ANCAs)** and does not typically involve eosinophilia as a defining feature [1]. *Cryoglobulinemia* - **Cryoglobulinemia** is a condition where abnormal immunoglobulins (cryoglobulins) precipitate in cold temperatures, leading to **vasculitis-like symptoms** in small and medium-sized vessels. - It often manifests as **palpable purpura**, **arthralgia**, and **glomerulonephritis**, but mononeuritis multiplex and elevated eosinophils are not primary or defining features.

Practice by Chapter

Rheumatoid Arthritis

Practice Questions

Spondyloarthropathies

Practice Questions

Systemic Lupus Erythematosus

Practice Questions

Vasculitis Syndromes

Practice Questions

Scleroderma and Related Disorders

Practice Questions

Inflammatory Myopathies

Practice Questions

Crystal Arthropathies

Practice Questions

Osteoarthritis

Practice Questions

Primary Immunodeficiency Disorders

Practice Questions

Autoinflammatory Syndromes

Practice Questions

Sjögren's Syndrome

Practice Questions

Antiphospholipid Syndrome

Practice Questions

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