Rheumatology and Immunology Practice Questions

Q: Anti-histone antibodies are characteristic of which condition?

Drug-induced lupus. **Explanation:** **1. Why Drug-Induced Lupus (DIL) is correct:** Anti-histone antibodies are the hallmark of Drug-Induced Lupus. They are present in **>95%** of patients with DIL. While these antibodies can also be found in systemic lupus erythematosus (SLE), their presence in the absence of other SLE-specific markers (like anti-dsDNA [1]) in a patient taking culprit medications is highly suggestive of DIL. **2. Why other options are incorrect:** * **Cardiac Lupus (Neonatal Lupus):** This is primarily associated with **Anti-Ro (SS-A)** and **Anti-La (SS-B)** antibodies [1], which cross the placenta and can cause congenital heart block. * **Lupus Nephritis:** This is strongly associated with high titers of **Anti-dsDNA** antibodies and low complement levels (C3, C4) [1]. Anti-histone antibodies do not correlate with renal involvement. * **Mixed Connective Tissue Disease (MCTD):** The defining serological marker for MCTD is high titers of **Anti-U1 RNP** antibodies [1]. **3. High-Yield Clinical Pearls for NEET-PG:** * **Common Culprit Drugs:** Remember the mnemonic **SHIPP**: **S**ulfonamides, **H**ydralazine (highest risk), **I**soniazid, **P**rocainamide (highest frequency), and **P**henytoin. Anti-TNF agents and Minocycline are also modern causes. * **Key Differences from SLE:** DIL typically spares the CNS and Kidneys. Malar rash and discoid lesions are rare. * **Prognosis:** Symptoms and antibody titers usually resolve within weeks to months after discontinuing the offending drug. * **Complement levels:** Unlike idiopathic SLE [1], complement levels are usually **normal** in DIL.

Q: Which of the following is the most specific test for rheumatoid arthritis?

Anti-MCV antibody. **Explanation:** The diagnosis of Rheumatoid Arthritis (RA) relies on identifying specific autoantibodies. While **Rheumatoid Factor (RF)** is the most sensitive initial test, it lacks specificity. The most specific markers for RA are antibodies against citrullinated proteins. **Why Anti-MCV is correct:** **Anti-MCV (Mutated Citrullinated Vimentin)** antibody is a type of Anti-Citrullinated Protein Antibody (ACPA). It has a **specificity of approximately 95-98%** for RA, which is comparable to or slightly higher than the standard Anti-CCP test. Clinically, Anti-MCV is highly significant because it correlates strongly with **disease activity** and the development of **radiographic joint damage** (erosions). In the context of this question, it is the only RA-specific marker listed. **Analysis of Incorrect Options:** * **B. Anti-cardiolipin antibody:** Associated with **Antiphospholipid Antibody Syndrome (APS)** and Systemic Lupus Erythematosus (SLE). It is linked to arterial/venous thrombosis and pregnancy loss. * **C. Anti-Mi-2 antibody:** A highly specific marker for **Dermatomyositis**. It is typically associated with a good prognosis and classic skin findings like Gottron’s papules. * **D. Anti-Ro (SS-A) antibody:** Primarily associated with **Sjögren’s syndrome** and SLE [1]. It is also linked to neonatal lupus and congenital heart block. **NEET-PG High-Yield Pearls:** * **Most Sensitive Test for RA:** Rheumatoid Factor (RF). * **Most Specific Test for RA:** Anti-CCP or Anti-MCV (ACPAs). * **Prognostic Value:** High titers of ACPA/Anti-MCV indicate a more aggressive, erosive disease course. * **Seronegative RA:** Refers to patients who have clinical RA but test negative for both RF and ACPAs [2].

Q: Circinate balanitis is a feature of which of the following conditions?

Reactive arthritis. **Explanation:** **Reactive Arthritis (ReA)** is the correct answer. It is a sterile inflammatory spondyloarthropathy that typically follows a gastrointestinal (e.g., *Salmonella, Shigella, Campylobacter*) or urogenital (e.g., *Chlamydia trachomatis*) infection [2]. **Circinate balanitis** is a pathognomonic cutaneous manifestation of ReA, characterized by painless, erythematous, superficial erosions with serpiginous borders on the glans penis [1], [2]. It occurs in approximately 20–40% of male patients with ReA [2]. **Analysis of Incorrect Options:** * **A. Osteoarthritis:** This is a degenerative joint disease characterized by cartilage loss and osteophyte formation; it does not involve systemic inflammatory or mucocutaneous lesions. * **B. Psoriatic Arthritis:** While it shares features like dactylitis and uveitis, its classic skin finding is plaque psoriasis. While "psoriasiform" lesions occur in ReA (Keratoderma blennorrhagicum), circinate balanitis is specifically linked to the triad of ReA [2]. * **D. Ankylosing Spondylitis:** Although it is the prototype of seronegative spondyloarthropathies, it primarily presents with sacroiliitis and inflammatory back pain rather than specific penile lesions. **High-Yield Clinical Pearls for NEET-PG:** * **Reiter’s Triad:** "Can't see (Uveitis/Conjunctivitis), can't pee (Urethritis), and can't climb a tree (Arthritis)." * **Keratoderma Blennorrhagicum:** Hyperkeratotic skin lesions on the palms and soles, histologically indistinguishable from pustular psoriasis [2]. * **HLA-B27 Association:** Strongly positive in 60–80% of cases [1]. * **Joint Involvement:** Typically an asymmetric oligoarthritis affecting the lower limbs (knees and ankles) [2].

Q: Shrinking lung syndrome is seen in which of the following conditions?

Systemic lupus erythematosus. **Explanation:** **Shrinking Lung Syndrome (SLS)** is a rare but characteristic respiratory complication of **Systemic Lupus Erythematosus (SLE)**. It is defined by progressive dyspnea, reduced lung volumes (restrictive pattern on PFTs), and elevated diaphragmatic domes on chest X-ray, notably in the **absence** of interstitial lung disease or pleural pathology [1]. The underlying pathophysiology is attributed to **diaphragmatic dysfunction** or weakness, likely due to a primary myopathy or phrenic nerve neuropathy [1]. **Analysis of Options:** * **Systemic Lupus Erythematosus (Correct):** SLS occurs in approximately 0.5% to 1.1% of SLE patients. It typically presents with pleuritic chest pain and a restrictive ventilatory defect [1]. * **Tuberous Sclerosis (Incorrect):** This neurocutaneous syndrome is associated with **Lymphangioleiomyomatosis (LAM)**, which presents with thin-walled cysts and recurrent pneumothorax, not SLS. * **Scleroderma (Incorrect):** While Scleroderma (Systemic Sclerosis) frequently involves the lungs, the classic manifestation is **Interstitial Lung Disease (NSIP pattern)** and Pulmonary Arterial Hypertension (PAH) [1]. * **Diabetes Mellitus (Incorrect):** DM is not associated with primary restrictive lung syndromes like SLS; pulmonary complications in DM are usually related to increased infection risk or sleep apnea. **NEET-PG High-Yield Pearls:** * **Most common lung manifestation in SLE:** Pleuritis (with or without effusion). * **Most common lung manifestation in Scleroderma:** Interstitial Lung Disease (ILD) [1]. * **SLS Treatment:** Corticosteroids are the first-line treatment; beta-agonists (theophylline) are sometimes used to improve diaphragmatic strength. * **Radiology of SLS:** Small lung volumes with "high-riding" diaphragms [1].

Q: Which of the following is true about polymyositis?

Ocular muscle involvement and muscle atrophy. **Explanation:** Polymyositis (PM) is an idiopathic inflammatory myopathy characterized by symmetric, subacute, progressive **proximal muscle weakness** [1]. **Why Option A is Correct:** The hallmark of Polymyositis is the **absence** of ocular and facial muscle involvement. This is a critical diagnostic differentiator. While proximal muscles (shoulders, hips) are severely affected, the extraocular muscles are characteristically spared. Furthermore, **muscle atrophy** is typically a late-stage finding in chronic, untreated, or severe cases of PM, occurring after significant muscle fiber necrosis and replacement by fibrous tissue. **Analysis of Incorrect Options:** * **B. Muscle atrophy:** While atrophy occurs, it is not the defining clinical feature compared to the specific exclusion of ocular involvement. * **C. Ocular muscle involvement and pharyngeal involvement:** While pharyngeal involvement (dysphagia) is common in PM [1], **ocular involvement is NOT**. If ocular muscles are involved, one must suspect Myasthenia Gravis [2] or Mitochondrial Myopathies. * **D. Ocular muscle involvement and brisk reflexes:** Again, ocular muscles are spared. Additionally, in PM, deep tendon reflexes (DTRs) are usually **normal** or decreased in late stages; brisk reflexes (hyperreflexia) suggest Upper Motor Neuron (UMN) lesions, not a primary muscle pathology. **High-Yield Clinical Pearls for NEET-PG:** * **Sparing:** PM/DM characteristically **spares** the extraocular and facial muscles. * **Diagnostic Markers:** Elevated **Creatine Kinase (CK)** and **Anti-Jo-1** antibodies (associated with interstitial lung disease) [1]. * **Biopsy:** PM shows **endomysial** inflammation with CD8+ T-cells, whereas Dermatomyositis shows **perimysial** inflammation with CD4+ T-cells. * **Malignancy:** Always screen for underlying malignancy in patients diagnosed with inflammatory myopathies (especially Dermatomyositis).

Q: Tophi in gout are found in all regions except?

Bone. The correct answer is **Bone**. While gout is a systemic metabolic disorder, the deposition of monosodium urate (MSU) crystals—known as **tophi**—follows a specific pattern of tissue predilection [1]. **1. Why Bone is the correct answer:** Tophi are essentially collections of MSU crystals surrounded by a granulomatous inflammatory response [1]. They typically deposit in **avascular or poorly vascularized tissues** (like cartilage and tendons) or cooler peripheral areas. While gout causes "punched-out" erosions in bone (Martel’s sign), the tophus itself is an **extracellular** deposit that occurs in the periarticular soft tissues, subchondral regions, or marrow spaces, but **not within the mineralized bone matrix** itself. In the context of this classic MCQ, bone is the site where tophi are least likely to be "found" as a primary site of deposition compared to soft tissues. **2. Analysis of other options:** * **Skin:** Subcutaneous tophi are very common, especially on the fingers, toes, and the helix of the ear [1]. * **Synovial membrane:** This is a primary site for crystal deposition, leading to the characteristic acute inflammatory synovitis [3, 4]. * **Muscle:** Although rare, tophi can deposit in connective tissue sheaths within or around muscles and tendons (e.g., Achilles tendon) [1]. **Clinical Pearls for NEET-PG:** * **Commonest site for Tophi:** The helix of the ear and the olecranon bursa [1]. * **Commonest joint involved:** 1st Metatarsophalangeal joint (Podagra) [3]. * **Polarizing Microscopy:** MSU crystals are **needle-shaped** and show **strong negative birefringence** (yellow when parallel to the axis). * **Radiology:** Look for "Punched-out" erosions with **overhanging edges** (Rat-bite erosions). * **Note:** Tophi usually develop after about 10 years of untreated chronic polyarticular gout [1].

Question 1

Anti-histone antibodies are characteristic of which condition?

Accepted Answer

Drug-induced lupus

Answer

Cardiac lupus

Answer

Lupus nephritis

Answer

Mixed connective tissue disease

Question 2

A 54-year-old man with a history of smoking presents with fever, hemoptysis, weight loss, and oligoarthritis. Serial skiagrams show fleeting opacities. What is the diagnosis?

Accepted Answer

Wegener's granulomatosis

Answer

Allergic Bronchopulmonary aspergillosis

Answer

Sarcoidosis

Answer

Tuberculosis

Question 3

What is the most common cause of polymyositis?

Accepted Answer

Staphylococcus

Answer

Pseudomonas

Answer

Brucella

Answer

Streptococcus

Question 4

Raynaud's phenomenon is seen in which of the following conditions?

Accepted Answer

Systemic Lupus Erythematosus and Systemic Sclerosis

Answer

Systemic Lupus Erythematosus

Answer

Systemic Lupus Erythematosus and Hypertension

Question 5

Which of the following is the most specific test for rheumatoid arthritis?

Accepted Answer

Anti-MCV antibody

Answer

Anti-cardiolipin antibody

Answer

Anti-Mi-2 antibody

Answer

Anti-Ro antibody

Question 6

Circinate balanitis is a feature of which of the following conditions?

Accepted Answer

Reactive arthritis

Answer

Osteoarthritis

Answer

Psoriatic arthritis

Answer

Ankylosing spondylitis

Question 7

Shrinking lung syndrome is seen in which of the following conditions?

Accepted Answer

Systemic lupus erythematosus

Answer

Tuberous sclerosis

Answer

Scleroderma

Answer

Diabetes mellitus

Question 8

A person suffers from HLA-B27 associated reactive arthritis, urethritis, and conjunctivitis. Which is the most likely organism involved in this case?

Accepted Answer

Ureaplasma urealyticum

Answer

Borrelia burgdorferi

Answer

Beta-hemolytic streptococci

Answer

Streptococcus bovis

Question 9

Which of the following is true about polymyositis?

Accepted Answer

Ocular muscle involvement and muscle atrophy

Answer

Muscle atrophy

Answer

Ocular muscle involvement and pharyngeal involvement

Answer

Ocular muscle involvement and brisk reflexes

Question 10

Tophi in gout are found in all regions except?

Accepted Answer

Bone

Answer

Skin

Answer

Muscle

Answer

Synovial membrane

Rheumatology and Immunology — MCQs

Rheumatology and Immunology — MCQs

On this page

Practice by Chapter

Want unlimited practice?