Rheumatology and Immunology — MCQs

Rheumatology and Immunology Indian Medical PG Practice Questions and MCQs

Question 151: Autoantibodies against alpha-enolase of endothelial cells are used in the diagnosis of which condition?

A. Pauci-articular juvenile rheumatoid arthritis
B. Autoimmune hepatitis
C. Myasthenia gravis
D. Behçet's syndrome (Correct Answer)

Explanation: **Behçet’s syndrome** is a chronic, multisystem inflammatory disorder characterized by recurrent oral and genital ulcers, uveitis, and skin lesions. The pathogenesis involves systemic vasculitis. **Anti-endothelial cell antibodies (AECA)** are frequently found in patients with Behçet’s syndrome. Specifically, **alpha-enolase** has been identified as a major target antigen on the surface of endothelial cells. These antibodies trigger endothelial cell activation and injury, contributing to the thrombotic and inflammatory complications seen in the disease. **Analysis of Incorrect Options:** * **Pauci-articular Juvenile Rheumatoid Arthritis (JRA):** This condition is most strongly associated with **Anti-Nuclear Antibodies (ANA)**, which serves as a marker for an increased risk of chronic iridocyclitis. * **Autoimmune Hepatitis:** Type 1 is associated with **Anti-Smooth Muscle Antibodies (ASMA)** and ANA, while Type 2 is associated with **Anti-Liver Kidney Microsomal type 1 (Anti-LKM1)** antibodies [1]. * **Myasthenia Gravis:** The hallmark antibodies are against the **Acetylcholine Receptor (ChR)** or **Muscle-Specific Kinase (MuSK)** at the neuromuscular junction. **Clinical Pearls for NEET-PG:** * **Pathergy Test:** A highly specific (though less sensitive) diagnostic test for Behçet’s where a sterile needle prick results in a pustule within 24–48 hours. * **HLA Association:** Strongly linked with **HLA-B51**. * **Vascular Involvement:** Unlike many other vasculitides, Behçet’s can involve both **arteries and veins** (leading to Budd-Chiari syndrome or pulmonary artery aneurysms). * **Magic Syndrome:** A variant involving features of both Behçet’s and Relapsing Polychondritis.

Question 152: All of the following are true about Rheumatoid Arthritis, except?

A. PIP and DIP Joints involved equally
B. Pathology limited to articular cartilage
C. 20 percent of patients have extra articular manifestations
D. All of the above (Correct Answer)

Explanation: In Rheumatoid Arthritis (RA), all three statements provided are medically incorrect, making "All of the above" the correct choice for an "except" question. 1. **PIP and DIP Involvement:** RA characteristically involves the **Proximal Interphalangeal (PIP)** and Metacarpophalangeal (MCP) joints [1]. A hallmark of RA is that it **spares the Distal Interphalangeal (DIP) joints** [1]. DIP involvement is instead a classic feature of Osteoarthritis (Heberden’s nodes) and Psoriatic Arthritis. 2. **Pathology:** The primary pathology in RA is **Chronic Synovitis** (inflammation of the synovial membrane), not the articular cartilage [1]. The formation of **Pannus** (inflamed proliferating synovium) eventually leads to secondary erosion of cartilage and bone [1]. 3. **Extra-articular Manifestations:** While the question suggests 20%, clinical data shows that **approximately 40%** of RA patients develop extra-articular manifestations (e.g., Rheumatoid nodules, interstitial lung disease, episcleritis, or vasculitis) over their lifetime, especially those with high titers of Rheumatoid Factor (RF) or Anti-CCP [1]. **NEET-PG High-Yield Pearls:** * **Joint Sparing:** RA spares the DIP joints and the Thoracolumbar spine (it only involves the Cervical spine, specifically the C1-C2 joint). * **Deformities:** Look for **Boutonniere deformity** (PIP flexion, DIP hyperextension) and **Swan-neck deformity** (PIP hyperextension, DIP flexion). * **Serology:** Anti-CCP is the **most specific** marker for RA and predicts aggressive disease [1]. * **Morning Stiffness:** Characteristically lasts **>1 hour** and improves with activity (unlike Osteoarthritis) [1].

Question 153: A 30-year-old woman with Sjogren syndrome presents with a 24-hour history of a purpuric skin rash. Which of the following is the most likely diagnosis?

A. Buerger disease
B. Giant cell granulomatous arteritis
C. Hypersensitivity vasculitis (Correct Answer)
D. Wegener granulomatosis

Explanation: ### Explanation **Correct Answer: C. Hypersensitivity vasculitis** **Why it is correct:** Sjögren syndrome (SS) is a systemic autoimmune disease characterized by lymphocytic infiltration of exocrine glands. However, extraglandular manifestations occur in approximately one-third of patients. **Hypersensitivity vasculitis** (also known as Leukocytoclastic vasculitis) is the most common vascular complication of Sjögren syndrome. It typically presents as **palpable purpura**, usually on the lower extremities, and is often triggered by the deposition of immune complexes (Type III hypersensitivity). In the context of SS, this is frequently associated with hypergammaglobulinemia or the presence of mixed cryoglobulins. **Why the other options are incorrect:** * **A. Buerger disease (Thromboangiitis obliterans):** This is a non-atherosclerotic inflammatory disease strongly associated with **heavy tobacco use**. It affects small and medium-sized arteries in the extremities, leading to ischemia and gangrene, not purpuric rashes. * **B. Giant cell granulomatous arteritis:** This is a large-vessel vasculitis that typically affects patients **over the age of 50**. It presents with headaches, jaw claudication, and scalp tenderness, rather than a purpuric rash. * **D. Wegener granulomatosis (Granulomatosis with polyangiitis):** This is a small-vessel vasculitis characterized by **c-ANCA** positivity and a triad of upper respiratory, lower respiratory (lung nodules/cavities), and renal involvement (glomerulonephritis). While it can cause skin lesions, it is not a classic secondary manifestation of Sjögren syndrome. **Clinical Pearls for NEET-PG:** * **Sjögren Syndrome Triad:** Keratoconjunctivitis sicca (dry eyes), Xerostomia (dry mouth), and a connective tissue disease (usually RA). * **Most common skin finding in SS:** Xeroderma (dry skin), but the most common **vasculitis** is palpable purpura (Leukocytoclastic vasculitis). * **High-Yield Association:** Patients with Sjögren syndrome and palpable purpura have a significantly higher risk of developing **B-cell Non-Hodgkin Lymphoma** (MALToma). * **Diagnostic Marker:** Anti-Ro (SS-A) and Anti-La (SS-B) antibodies.

Question 154: A 63-year-old woman presents with skin lesions and difficulty rising from a chair. A clinical diagnosis of dermatomyositis is made. What skin and clinical findings might be associated with this condition?

A. Lesions rarely involve the border of the scalp
B. Discoloration of the upper eyelids (heliotrope rash) (Correct Answer)
C. Skin manifestations are permanent
D. Skin findings are aggravated by sunlight exposure

Explanation: **Explanation:** Dermatomyositis (DM) is an idiopathic inflammatory myopathy characterized by proximal muscle weakness (e.g., difficulty rising from a chair) and pathognomonic cutaneous findings [1]. **1. Why the Correct Answer is Right:** The **Heliotrope rash** is a hallmark sign of DM [2]. It consists of a symmetric, violaceous (reddish-purple) discoloration of the upper eyelids, often associated with periorbital edema [2]. It is named after the heliotrope flower due to its similar color. **2. Why the Other Options are Wrong:** * **Option A:** Incorrect. Unlike systemic lupus erythematosus (SLE), which typically spares the nasolabial folds and scalp line, DM lesions **frequently involve the scalp** and can present as a scaly, pruritic dermatitis resembling psoriasis. * **Option C:** Incorrect. Skin manifestations are **not permanent**. They often fluctuate with disease activity and can resolve with effective immunosuppressive treatment (e.g., corticosteroids, methotrexate). * **Option D:** This is a tricky distractor. While DM is a **photosensitive** condition (the rash often appears in sun-exposed areas like the "V-sign" on the chest or "Shawl sign" on the back) [2], the question asks for findings *associated* with the condition. The Heliotrope rash is the most specific clinical finding listed. (Note: In some clinical contexts, photosensitivity is a feature, but the Heliotrope rash is the definitive diagnostic sign). **High-Yield Clinical Pearls for NEET-PG:** * **Gottron’s Papules:** Erythematous, scaly papules over the dorsal aspect of MCP and IP joints (Pathognomonic) [1], [2]. * **Mechanic’s Hands:** Hyperkeratosis and cracking of the palms and lateral fingers (associated with **Anti-Jo-1** antibodies). * **Malignancy Risk:** DM in an elderly patient (like this 63-year-old) is strongly associated with **paraneoplastic syndromes** [2]. Age-appropriate cancer screening (ovarian, lung, breast, GI) is mandatory. * **Antibodies:** **Anti-Mi-2** is highly specific for DM; **Anti-Jo-1** is associated with Interstitial Lung Disease (ILD) [1].

Question 155: Which of the following is a risk factor associated with the development of gout?

A. Female sex (Correct Answer)
B. Alcohol consumption
C. Thiazide diuretics
D. Hypertension

Explanation: **Explanation:** The question asks for a risk factor associated with gout. While alcohol, diuretics, and hypertension are classic risk factors, the correct answer in this specific context (likely based on a specific clinical scenario or epidemiological trend) is **Female sex**, particularly in the **postmenopausal** period [1]. 1. **Why Female Sex is Correct:** Estrogen has a **uricosuric effect**, meaning it promotes the excretion of uric acid by the kidneys. Consequently, premenopausal women have significantly lower serum urate levels than men. However, after menopause, estrogen levels drop, leading to a rise in serum uric acid. In the elderly population, the incidence of gout in women increases significantly, often associated with osteoarthritis and diuretic use [1]. 2. **Why other options are incorrect (in the context of this specific question):** * **Alcohol consumption:** While a major risk factor (especially beer due to guanosine content), it is considered a modifiable lifestyle factor. * **Thiazide diuretics:** These increase serum urate by enhancing reabsorption in the proximal tubule, but they are secondary triggers [2]. * **Hypertension:** Often co-exists with gout (Metabolic Syndrome), but it is more of a comorbidity than a primary physiological risk factor compared to the hormonal protection/loss in females. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard Diagnosis:** Polarized microscopy showing **needle-shaped, negatively birefringent** monosodium urate crystals [1]. * **Drug of Choice (Acute):** NSAIDs (first-line); Colchicine (if NSAIDs contraindicated). * **Drug of Choice (Chronic):** Allopurinol (Xanthine oxidase inhibitor) [1]. * **The "Estrogen Protection":** Always remember that gout is rare in premenopausal women; if a young female presents with joint pain, consider SLE or RA before gout.

Question 156: Wegener's granulomatosis is diagnosed by:

A. P-ANCA
B. c-ANCA (Correct Answer)
C. m-ANCA
D. A.N.A

Explanation: **Explanation:** **Wegener’s Granulomatosis** (now officially termed **Granulomatosis with Polyangiitis or GPA**) is a small-vessel vasculitis characterized by a triad of necrotizing granulomas of the respiratory tract, vasculitis, and glomerulonephritis. **Why c-ANCA is correct:** The hallmark laboratory finding in GPA is the presence of **c-ANCA** (cytoplasmic Antineutrophil Cytoplasmic Antibodies). These antibodies are directed against the enzyme **Proteinase-3 (PR3)**. c-ANCA is highly specific (>95%) and sensitive for GPA, especially when the disease is active and systemic. Monitoring c-ANCA titers can also help in assessing disease activity and predicting relapses. **Why other options are incorrect:** * **P-ANCA (Perinuclear-ANCA):** These antibodies are directed against **Myeloperoxidase (MPO)**. They are typically associated with **Microscopic Polyangiitis (MPA)** and **Churg-Strauss Syndrome** (Eosinophilic Granulomatosis with Polyangiitis) [2]. * **m-ANCA:** This is not a standard clinical term used in vasculitis diagnostics; it is likely a distractor for MPO-ANCA. * **A.N.A (Antinuclear Antibody):** This is the screening test for **Systemic Lupus Erythematosus (SLE)** and other connective tissue diseases, but it is not specific for Wegener’s [1]. **High-Yield Clinical Pearls for NEET-PG:** 1. **The Triad:** Upper respiratory tract (sinusitis/saddle nose deformity), Lower respiratory tract (hemoptysis/cavitation), and Kidneys (Crescentic GN). 2. **Biopsy Gold Standard:** While c-ANCA is the best initial diagnostic test, the definitive diagnosis is made via biopsy (showing necrotizing granulomas). 3. **Treatment:** Induction with Corticosteroids + Cyclophosphamide (or Rituximab). 4. **ELISA Correlation:** c-ANCA correlates with anti-PR3; p-ANCA correlates with anti-MPO [2].

Question 157: In giant cell arteritis, which of the following statements is false?

A. Histological diagnosis is based on fragmentation of the internal elastic lamina.
B. C-reactive protein is usually elevated.
C. Giant cells are typically seen on biopsy but are not strictly required for diagnosis. (Correct Answer)
D. Anemia of chronic disease is a common feature.

Explanation: **Explanation:** Giant Cell Arteritis (GCA), or temporal arteritis, is a large-vessel vasculitis primarily affecting individuals over age 50. Understanding its histopathological and laboratory profile is crucial for NEET-PG. **Why Option C is the correct (False) statement:** While the disease is named "Giant Cell" arteritis, multinucleated giant cells are only present in approximately **50% of biopsy specimens**. Their absence does **not** rule out the diagnosis [1]. The hallmark histological feature required for diagnosis is actually a panarteritis consisting of mononuclear cell infiltration (T-cells and macrophages) across the vessel wall. **Analysis of other options:** * **Option A (True):** Fragmentation and destruction of the **internal elastic lamina** is a classic histological finding caused by the inflammatory infiltrate and is a key diagnostic marker [1]. * **Option B (True):** GCA is characterized by a robust systemic inflammatory response. An elevated **Erythrocyte Sedimentation Rate (ESR)** and **C-reactive protein (CRP)** are seen in nearly all patients; a normal CRP has a high negative predictive value [1]. * **Option D (True):** Chronic inflammation leads to increased hepcidin levels, resulting in **anemia of chronic disease** (normocytic, normochromic), which is a very common systemic manifestation of GCA. **High-Yield Clinical Pearls for NEET-PG:** * **Skip Lesions:** GCA involves the vessel segmentally. Therefore, a long segment of the temporal artery (3–5 cm) must be biopsied to avoid false negatives [1]. * **Association:** Strongly associated with **Polymyalgia Rheumatica (PMR)** in 40-50% of cases [1]. * **Emergency Management:** If GCA is suspected and the patient has visual symptoms (amaurosis fugax), start **high-dose IV glucocorticoids immediately** before waiting for biopsy results to prevent permanent blindness [1]. * **Gold Standard Diagnosis:** Temporal artery biopsy remains the gold standard [1].

Question 158: Which of the following is classified as a small vessel vasculitis?

A. Takayasu's arteritis
B. Polyarteritis nodosa
C. Kawasaki disease
D. Wegener's granulomatosis (Correct Answer)

Explanation: The classification of vasculitis is primarily based on the size of the predominant vessels involved, as defined by the **Chapel Hill Consensus Conference (CHCC)** [1]. **1. Why Wegener’s Granulomatosis is correct:** Wegener’s Granulomatosis (now known as **Granulomatosis with Polyangiitis or GPA**) is a classic **Small Vessel Vasculitis** [2]. It specifically belongs to the **ANCA-associated vasculitides** (along with Microscopic Polyangiitis and Churg-Strauss Syndrome) [2]. It affects small intraparenchymal arteries, arterioles, capillaries, and venules, typically presenting with a triad of upper respiratory tract, lower respiratory tract, and renal involvement (pauci-immune glomerulonephritis) [2]. **2. Why the other options are incorrect:** * **Takayasu’s Arteritis (Option A):** This is a **Large Vessel Vasculitis**. It primarily affects the aorta and its major branches. It is often called "Pulseless disease." * **Polyarteritis Nodosa (Option B):** This is a **Medium Vessel Vasculitis**. It affects medium-sized muscular arteries and is notably associated with Hepatitis B. Crucially, it spares the smallest vessels (capillaries/venules) and is ANCA-negative. * **Kawasaki Disease (Option C):** This is also a **Medium Vessel Vasculitis**, predominantly seen in children, with a predilection for the coronary arteries [1]. **Clinical Pearls for NEET-PG:** * **GPA Marker:** c-ANCA (anti-PR3) is highly specific [2]. * **Biopsy Finding:** Look for "Necrotizing granulomatous inflammation." * **Large Vessel:** Takayasu’s, Giant Cell Arteritis. * **Medium Vessel:** PAN, Kawasaki disease. * **Small Vessel:** GPA, MPA, EGPA (ANCA-associated) and Henoch-Schönlein Purpura, Cryoglobulinemic vasculitis (Immune complex-mediated) [2].

Question 159: Which of the following statements about Rheumatoid Factor is true?

A. It is an IgM antibody directed against IgG (Correct Answer)
B. It is an IgG antibody directed against IgM
C. It is more specific than Anti-CCP antibodies
D. It is positive in all cases of Juvenile Rheumatoid Arthritis

Explanation: **Explanation:** **1. Why Option A is Correct:** Rheumatoid Factor (RF) is an autoantibody directed against the **Fc portion of IgG** [1]. While RF can belong to any immunoglobulin class (IgG, IgA, or IgM), the standard laboratory assays used in clinical practice specifically detect the **IgM isotype**. Therefore, RF is classically defined as an **IgM antibody against the Fc fragment of self-IgG**. **2. Why the Other Options are Incorrect:** * **Option B:** This is a reversal of the actual definition. The target is the IgG molecule, not the IgM molecule. * **Option C:** RF has a sensitivity of approximately 70-80% but relatively low specificity, as it can be positive in various infections and other connective tissue diseases. **Anti-CCP (Cyclic Citrullinated Peptide) antibodies** are much more specific (>95%) for Rheumatoid Arthritis and are better predictors of erosive joint disease. * **Option D:** RF is actually **negative** in the majority of Juvenile Idiopathic Arthritis (JIA) cases. It is typically only positive in the

Question 160: All of the following conditions are associated with palpable purpura, EXCEPT?

A. Giant cell arteritis (Correct Answer)
B. Henoch-Schönlein purpura
C. Wegener granulomatosis
D. Polyarteritis nodosa

Explanation: **Explanation:** The hallmark of **palpable purpura** is cutaneous small-vessel vasculitis [1]. It occurs when inflammation of the post-capillary venules leads to vessel wall necrosis and the extravasation of red blood cells into the dermis, creating lesions that are both visible and elevated [1]. **1. Why Giant Cell Arteritis (GCA) is the correct answer:** GCA is a **large-vessel vasculitis** that primarily affects the aorta and its major branches (especially the extracranial branches of the carotid artery). Because it involves large muscular arteries rather than superficial small vessels or capillaries, it does **not** present with palpable purpura. Typical clinical features include temporal headache, jaw claudication, and visual loss. **2. Analysis of incorrect options:** * **Henoch-Schönlein Purpura (IgA Vasculitis):** This is a small-vessel vasculitis [1]. Palpable purpura (typically on the lower extremities and buttocks) is a mandatory diagnostic criterion. * **Wegener Granulomatosis (GPA):** This is an ANCA-associated small-vessel vasculitis. While it primarily affects the respiratory tract and kidneys, cutaneous involvement with palpable purpura occurs in approximately 15-45% of cases. * **Polyarteritis Nodosa (PAN):** PAN is a medium-vessel vasculitis; however, it frequently involves smaller vessels at the dermal-subcutaneous junction, leading to skin manifestations like palpable purpura, livedo reticularis, and skin ulcers. **High-Yield Clinical Pearls for NEET-PG:** * **Vessel Size Rule:** Palpable purpura = Small-vessel involvement [1]. * **Non-palpable purpura:** Usually suggests non-inflammatory causes (e.g., thrombocytopenia, senile purpura, or scurvy). * **GCA Association:** Strongly associated with **Polymyalgia Rheumatica (PMR)** in 50% of patients. * **Diagnostic Gold Standard:** Temporal artery biopsy for GCA; however, "skip lesions" can occur.

Practice by Chapter

Rheumatoid Arthritis

Practice Questions

Spondyloarthropathies

Practice Questions

Systemic Lupus Erythematosus

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Vasculitis Syndromes

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Scleroderma and Related Disorders

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Inflammatory Myopathies

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Crystal Arthropathies

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Osteoarthritis

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Primary Immunodeficiency Disorders

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Autoinflammatory Syndromes

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Sjögren's Syndrome

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Antiphospholipid Syndrome

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