Rheumatology and Immunology Practice Questions

Q: Which of the following is true about Systemic Lupus Erythematosus (SLE)?

All of the above are true.. Systemic Lupus Erythematosus (SLE) is a chronic, multisystem autoimmune disease characterized by the production of autoantibodies against nuclear antigens, leading to widespread inflammation and tissue damage. [1] **Explanation of Options:** * **Option A (Autoimmune Disease):** SLE is the prototype of systemic autoimmune diseases. It involves a loss of self-tolerance where B-cells and T-cells become hyperactive, leading to the formation of immune complexes that deposit in organs like the kidneys, skin, and joints (Type III Hypersensitivity). * **Option B (Childhood vs. Adult SLE):** Pediatric-onset SLE (cSLE) typically presents with a more aggressive clinical course than adult-onset SLE. Children have a higher prevalence of major organ involvement, particularly **Lupus Nephritis** and central nervous system (CNS) disease, leading to higher morbidity and a poorer long-term prognosis. * **Option C (ANA Presence):** Antinuclear antibodies (ANA) are the hallmark of SLE. They are present in >95% of patients, making ANA the **best initial screening test** due to its high sensitivity. [2] **NEET-PG High-Yield Clinical Pearls:** 1. **Most Specific Antibodies:** While ANA is most sensitive, **Anti-dsDNA** and **Anti-Smith (Anti-Sm)** antibodies are the most specific for SLE. [2] Anti-dsDNA levels also correlate with disease activity and lupus nephritis. 2. **Drug-Induced Lupus (DIL):** Characterized by **Anti-Histone antibodies**. Common triggers include Hydralazine, Procainamide, and Isoniazid. It rarely involves the CNS or kidneys. 3. **Complement Levels:** During active flares (especially renal), C3 and C4 levels are typically **decreased** due to consumption. 4. **Libman-Sacks Endocarditis:** A classic cardiac manifestation involving small, sterile vegetations on both sides of the heart valves.

Q: All of the following are increased in rheumatoid arthritis, except?

Synovial fluid viscosity. **Explanation:** In Rheumatoid Arthritis (RA), the hallmark of joint involvement is **inflammatory synovitis**. This inflammatory process directly alters the composition of synovial fluid, leading to a **decrease in synovial fluid viscosity** [1]. 1. **Why Synovial Fluid Viscosity is Decreased:** Normal synovial fluid is highly viscous due to a high concentration of **Hyaluronan (Hyaluronic acid)**. In RA, the inflamed synovium produces inflammatory cytokines and enzymes that degrade hyaluronan [1]. Additionally, the rapid influx of neutrophils and increased fluid volume (effusion) dilutes the hyaluronan. This results in "watery" synovial fluid that fails the "string sign" test, making it the correct answer as it decreases rather than increases. 2. **Analysis of Other Options:** * **ESR (Erythrocyte Sedimentation Rate):** This is an acute-phase reactant. In active RA, systemic inflammation leads to increased production of fibrinogen, which causes RBCs to stack (rouleaux formation), thereby **increasing** the ESR [2]. * **Rheumatoid Factor (RF):** An autoantibody (usually IgM) directed against the Fc portion of IgG [3]. It is **increased** (positive) in approximately 70-80% of RA patients [2]. * **Anti-CCP Antibodies:** These are highly specific for RA. Their levels are **increased** and are often used for early diagnosis and predicting aggressive disease [2]. **Clinical Pearls for NEET-PG:** * **Synovial Fluid Analysis:** In RA, the fluid is inflammatory (WBC count typically 2,000–50,000/mm³). * **Most Specific Marker:** Anti-CCP (Cyclic Citrullinated Peptide) is more specific for RA than RF [2]. * **Poor Prognostic Factors:** High titers of RF/Anti-CCP, presence of HLA-DR4, and early erosions on X-ray. * **String Sign:** Normal synovial fluid forms a 3–5 cm string; in RA, this string breaks immediately due to low viscosity.

Q: All of the following are true about Drug Induced Lupus, except?

Renal involvement. **Explanation:** Drug-Induced Lupus (DIL) is a syndrome that mimics Systemic Lupus Erythematosus (SLE) but is triggered by specific medications. The key to answering this question lies in distinguishing the clinical and serological profile of DIL from idiopathic SLE. **Why "Renal Involvement" is the correct answer:** Unlike idiopathic SLE, **Drug-Induced Lupus typically spares the kidneys and the Central Nervous System (CNS).** Renal involvement and malar rash are characteristically absent or extremely rare in DIL. If a patient presents with significant proteinuria or seizures, idiopathic SLE is a much more likely diagnosis. **Analysis of other options:** * **A. Anti-histone antibody:** This is the hallmark of DIL, present in >95% of cases. While not 100% specific (it can appear in idiopathic SLE), its presence in the absence of other antibodies is highly suggestive of DIL. * **B. Rare anti-dsDNA:** Anti-dsDNA antibodies, which are highly specific for idiopathic SLE, are characteristically absent in DIL (except in cases induced by TNF-alpha inhibitors). * **D. Serositis:** DIL frequently presents with systemic symptoms like fever, arthralgia, and **serositis** (pleuritis or pericarditis). These are common clinical manifestations of the condition. **NEET-PG High-Yield Pearls:** 1. **Most Common Drugs:** Procainamide (highest risk), Hydralazine (most common cause), Isoniazid, Phenytoin, and Quinidine. 2. **Genetic Predisposition:** "Slow acetylators" (deficiency in N-acetyltransferase) are at a higher risk of developing DIL. 3. **Prognosis:** Symptoms usually resolve within weeks of discontinuing the offending drug. 4. **Complement levels:** Unlike idiopathic SLE, complement levels (C3, C4) are usually **normal** in DIL.

Q: This lesion is most commonly seen in which disease?

Psoriatic Arthritis. ***Psoriatic Arthritis*** - **Psoriatic plaques** with silvery-white scales on an erythematous base are the classic skin manifestation strongly associated with psoriatic arthritis. - **Nail pitting** and **onycholysis** (nail separation) are characteristic nail changes that occur in up to 80% of patients with psoriatic arthritis. *Rheumatoid Arthritis* - Does not typically present with **psoriatic skin lesions** or characteristic nail changes. - Skin manifestations are limited to **rheumatoid nodules** over bony prominences, not scaly plaques. *Ankylosing spondylitis* - Primarily affects the **axial skeleton** without characteristic skin lesions like psoriatic plaques. - May have **uveitis** or **inflammatory bowel disease** associations, but not dermatological manifestations. *Gout* - Characteristic lesions are **tophi** (uric acid crystal deposits), not psoriatic plaques. - Skin changes include **chalky white deposits** around joints, particularly the ears and fingers, distinct from scaly erythematous plaques.

Q: What is the first-choice disease-modifying antirheumatic drug (DMARD) in rheumatoid arthritis?

Methotrexate. **Explanation:** **Methotrexate (MTX)** is the "Anchor Drug" and the first-line Disease-Modifying Antirheumatic Drug (DMARD) for Rheumatoid Arthritis (RA). Its status as the gold standard is due to its proven efficacy, favorable safety profile, low cost, and ability to reduce radiological progression of the disease. * **Mechanism:** It is a folate antimetabolite that inhibits the enzyme **dihydrofolate reductase**. In RA, its anti-inflammatory effect is primarily mediated by increasing extracellular **adenosine** levels, which inhibits T-cell activation. * **Administration:** It is typically started at 7.5–15 mg once weekly (never daily) along with Folic acid supplementation to reduce gastrointestinal and mucosal side effects. **Why other options are incorrect:** * **Gold salts & Penicillamine:** These are "historical DMARDs." While effective, they are rarely used today due to significant toxicities (e.g., nephrotic syndrome, bone marrow suppression) and the availability of safer alternatives. * **Sulfasalazine:** While a valid conventional synthetic DMARD (csDMARD), it is generally considered second-line or used as part of "Triple Therapy" (Methotrexate + Sulfasalazine + Hydroxychloroquine). It is often the preferred choice in pregnant patients where MTX is contraindicated. **High-Yield Clinical Pearls for NEET-PG:** * **Monitoring:** Baseline CBC, LFTs, and Renal Function Tests are mandatory. Watch for **hepatotoxicity** (fibrosis) and **pneumonitis**. * **Contraindications:** Pregnancy (Category X - Teratogenic), chronic liver disease, and severe renal failure. * **Fastest Acting:** Among conventional DMARDs, MTX has a relatively quick onset (4–6 weeks). * **Leflunomide** is the best alternative if a patient is intolerant to Methotrexate.

Question 1

Which of the following is true about Systemic Lupus Erythematosus (SLE)?

Accepted Answer

All of the above are true.

Answer

It is an autoimmune disease.

Answer

Childhood SLE has a poorer prognosis than adult SLE.

Answer

Antinuclear antibodies (ANA) are often present.

Question 2

All of the following are increased in rheumatoid arthritis, except?

Accepted Answer

Synovial fluid viscosity

Answer

ESR levels

Answer

Rheumatoid factor

Answer

Anti-CCP Antibodies

Question 3

During the winter months, a 65-year-old man presents with livedo reticularis and purple fingertips. Other symptoms include arthralgia and weakness. Renal impairment is present on laboratory testing. Which of the following is the most likely diagnosis?

Accepted Answer

cryoglobulinemia

Answer

cold agglutinin disease

Answer

Henoch-Schonlein purpura

Answer

antiphospholipid antibody syndrome

Question 4

All of the following are true about Drug Induced Lupus, except?

Accepted Answer

Renal involvement

Answer

Anti-histone antibody

Answer

Rare anti-ds DNA

Answer

Serositis

Question 5

Which of the following conditions does NOT typically cause bone erosion?

Accepted Answer

Systemic Lupus Erythematosus (SLE)

Answer

Psoriasis

Answer

Rheumatoid Arthritis (RA)

Answer

Gout

Question 6

A 19-year-old man has a chronic papulosquamous skin disorder involving his knees and elbows. He now has dull low back pain and morning stiffness that lasts a few hours. On examination, forward flexion at the lumbar spine is reduced, but neck movements are normal. There is stress tenderness of both sacroiliac joints. Which of the following is the most likely diagnosis?

Accepted Answer

Psoriatic arthritis

Answer

Rheumatoid arthritis

Answer

Ankylosing spondylitis

Answer

Reactive arthritis

Question 7

In giant cell arteritis, which of the following is true?

Accepted Answer

Giant cells are needed for diagnosis.

Answer

Histological diagnosis is based on fragmentation of the internal elastic lamina.

Answer

C-reactive protein is always raised.

Answer

Anemia is a feature.

Question 8

A 25-year-old normotensive patient presents to the emergency department with breathlessness and palpitations. The patient has a history of allergy to peanuts and accidentally ingested them. On examination, the patient's heart rate is 120/min and blood pressure is 100/60 mm Hg. An urgent X-ray was performed. What is the most likely diagnosis?

Accepted Answer

Non-cardiogenic pulmonary edema

Answer

Cardiogenic pulmonary edema

Answer

Pulmonary embolism

Answer

Atrial septal defect

Question 9

This lesion is most commonly seen in which disease?

Accepted Answer

Psoriatic Arthritis

Answer

Rheumatoid Arthritis

Answer

Ankylosing spondylitis

Answer

Gout

Question 10

What is the first-choice disease-modifying antirheumatic drug (DMARD) in rheumatoid arthritis?

Accepted Answer

Methotrexate

Answer

Gold salts

Answer

Penicillamine

Answer

Sulfasalazine

Rheumatology and Immunology — MCQs

Rheumatology and Immunology — MCQs

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