Rheumatology and Immunology — MCQs

A 29-year-old man presents with a 3-day history of burning pain on urination and urethral discharge. ELISA testing of the urethral exudate is positive for Chlamydia trachomatis. Three weeks later, he develops increasing stiffness of his knees and ankles and lower back pain. Radiographs of his lumbar spine reveal narrowing and sclerosis of the sacroiliac joints. One month later, he experiences painful erythema of the glans penis, and his conjunctivae become red. A follow-up examination reveals a slightly irregular heart rate and a murmur suggestive of aortic regurgitation. The back pain recurs intermittently for 5 more months. Which of the following test results is most likely to be positive in this man?

Q35Medium

Which of the following statements is FALSE about reactive arthritis?

Q36Easy

Which of the following is NOT a minor Jones criterion?

Q37Easy

HLA-B27 antigen is associated with all of the following conditions except?

Q38Easy

Which of the following are characteristics of Sjögren's syndrome?

Q39Medium

Palpable purpura is seen in which of the following conditions?

Q40Easy

In a case of undifferentiated arthritis, the presence of anti-cyclic citrullinated peptide (anti-CCP) antibodies strongly indicates the possibility of which of the following conditions?

Rheumatology and Immunology Indian Medical PG Practice Questions and MCQs

Question 31: Thymoma with hypogammaglobulinemia is also known as:

A. Good's syndrome (Correct Answer)
B. Capgras syndrome
C. Fregoli syndrome
D. Todd syndrome

Explanation: **Explanation:** **1. Correct Answer: Good’s Syndrome** Good’s syndrome is a rare secondary immunodeficiency characterized by the triad of **thymoma, hypogammaglobulinemia, and low or absent B-cells**. It typically presents in the 4th or 5th decade of life. The underlying pathophysiology involves a defect in hematopoietic stem cells, leading to reduced humoral and cell-mediated immunity. Patients are highly susceptible to opportunistic infections (fungal, viral, and bacterial) and sinopulmonary infections. Unlike Myasthenia Gravis, surgical removal of the thymoma does not usually reverse the hypogammaglobulinemia. **2. Analysis of Incorrect Options:** * **Capgras Syndrome:** A psychiatric delusional misidentification syndrome where a person believes that a friend, spouse, or close family member has been replaced by an identical-looking impostor. * **Fregoli Syndrome:** Another psychiatric delusion where the patient believes that different people are actually a single person in disguise who is following or persecuting them. * **Todd Syndrome (Alice in Wonderland Syndrome):** A neurological condition characterized by distorted perception (metamorphopsia), where objects or body parts appear much larger (macropsia) or smaller (micropsia) than they are. It is often associated with migraines or epilepsy. **3. High-Yield Clinical Pearls for NEET-PG:** * **Classic Triad:** Thymoma + Hypogammaglobulinemia + Low B-cells. * **Associated Conditions:** Thymoma is most commonly associated with **Myasthenia Gravis** (30-45% of cases) [1], but Good’s syndrome occurs in only about 5% of thymoma patients. * **Immunology:** Look for low serum IgG, IgA, and IgM levels and a reversed CD4/CD8 T-cell ratio. * **Management:** Treatment involves IVIG (Intravenous Immunoglobulin) replacement and management of the thymoma [1].

Question 32: Which vasculitis is positive for pANCA?

A. Wegener's granulomatosis
B. Churg-Strauss syndrome (Correct Answer)
C. Polyarteritis nodosa
D. All of the above

Explanation: The correct answer is **Churg-Strauss syndrome** (now known as Eosinophilic Granulomatosis with Polyangiitis or EGPA). **1. Why Churg-Strauss syndrome is correct:** ANCA-associated vasculitides are characterized by the presence of Antineutrophil Cytoplasmic Antibodies. **pANCA** (perinuclear) primarily targets the enzyme **myeloperoxidase (MPO)**. Approximately 40–60% of patients with Churg-Strauss syndrome are pANCA positive [1]. It is clinically defined by the triad of asthma, hypereosinophilia, and necrotizing vasculitis [1]. **2. Why the other options are incorrect:** * **Wegener’s granulomatosis (GPA):** This is classically associated with **cANCA** (cytoplasmic), which targets **Proteinase-3 (PR3)**. While pANCA can rarely occur, cANCA is the hallmark (90% sensitivity in active disease). * **Polyarteritis nodosa (PAN):** PAN is a medium-vessel vasculitis that is characteristically **ANCA-negative**. Its pathogenesis is often linked to Hepatitis B surface antigen, not antineutrophil antibodies. * **All of the above:** Incorrect because PAN is ANCA-negative and Wegener’s is predominantly cANCA-positive. **3. NEET-PG High-Yield Clinical Pearls:** * **pANCA (MPO-ANCA) Positive:** Churg-Strauss syndrome, Microscopic Polyangiitis (MPA), and Primary Sclerosing Cholangitis (PSC). * **cANCA (PR3-ANCA) Positive:** Granulomatosis with Polyangiitis (Wegener’s). * **Rule of Thumb:** If a question mentions "pauci-immune glomerulonephritis" with lung involvement, think of ANCA-associated vasculitis. * **Churg-Strauss Key Feature:** Look for "Asthma" or "Eosinophilia" in the clinical vignette to differentiate it from MPA or Wegener’s [1].

Question 33: What is the typical sequence of color changes observed in Raynaud's disease?

A. Red, blue, white
B. White, blue, red (Correct Answer)
C. Blue, red, white
D. White, red, blue

Explanation: **Explanation:** Raynaud’s phenomenon is a reversible vasospastic disorder of the digital arteries, typically triggered by cold exposure or emotional stress. The classic "triphasic" color change follows a specific physiological sequence: 1. **White (Pallor):** This is the initial phase caused by intense **vasoconstriction** of the precapillary arterioles, leading to a lack of blood flow (ischemia) to the digits. 2. **Blue (Cyanosis):** As the ischemia persists, the stagnant blood in the capillaries and venules becomes deoxygenated, resulting in a bluish discoloration. 3. **Red (Rubor):** Once the stimulus is removed, the vasospasm resolves, leading to **reactive hyperemia** (sudden reperfusion). The rapid return of oxygenated blood causes the digits to turn bright red, often accompanied by throbbing or pain. **Analysis of Incorrect Options:** * **Options A, C, and D:** These sequences are incorrect because they do not follow the physiological progression from ischemia (white) to deoxygenation (blue) and finally to reperfusion (red). **NEET-PG High-Yield Pearls:** * **Primary Raynaud’s (Disease):** Usually idiopathic, symmetric, and lacks underlying tissue damage (gangrene). * **Secondary Raynaud’s (Phenomenon):** Often associated with connective tissue diseases, most commonly **Systemic Sclerosis (Scleroderma)**. * **Drug of Choice:** Calcium Channel Blockers (specifically **Nifedipine**) are the first-line treatment. * **Capillaroscopy:** Used to differentiate primary from secondary; "giant capillaries" or "dropout areas" suggest an underlying systemic disease.

Question 34: A 29-year-old man presents with a 3-day history of burning pain on urination and urethral discharge. ELISA testing of the urethral exudate is positive for Chlamydia trachomatis. Three weeks later, he develops increasing stiffness of his knees and ankles and lower back pain. Radiographs of his lumbar spine reveal narrowing and sclerosis of the sacroiliac joints. One month later, he experiences painful erythema of the glans penis, and his conjunctivae become red. A follow-up examination reveals a slightly irregular heart rate and a murmur suggestive of aortic regurgitation. The back pain recurs intermittently for 5 more months. Which of the following test results is most likely to be positive in this man?

A. ANCA
B. ANA
C. HLA-B27 genotype (Correct Answer)
D. Anti-Borrelia antibodies

Explanation: ### Explanation The clinical presentation describes a classic case of **Reactive Arthritis** (formerly known as Reiter’s Syndrome), characterized by the triad of **Urethritis, Conjunctivitis, and Arthritis** ("Can't see, can't pee, can't climb a tree") [3]. **Why HLA-B27 is the correct answer:** Reactive arthritis is a member of the **Seronegative Spondyloarthritides** group. It typically occurs 1–4 weeks following a urogenital (e.g., *Chlamydia trachomatis*) or gastrointestinal (e.g., *Salmonella, Shigella, Campylobacter*) infection [1], [3]. This patient exhibits classic features: asymmetric oligoarthritis (knees/ankles), sacroiliitis (back pain/sclerosis) [2], and extra-articular manifestations like **circinate balanitis** (painful erythema of the glans penis) and **aortic regurgitation** (due to aortitis). Approximately **60–80%** of patients with Reactive Arthritis are positive for the **HLA-B27 genotype**, which is strongly associated with axial involvement (sacroiliitis) and chronicity [1]. **Why other options are incorrect:** * **ANCA (Anti-Neutrophil Cytoplasmic Antibodies):** Associated with small-vessel vasculitides (e.g., Granulomatosis with polyangiitis), not spondyloarthropathies. * **ANA (Anti-Nuclear Antibody):** A screening test for Systemic Lupus Erythematosus (SLE) and other connective tissue diseases. Reactive arthritis is "seronegative," meaning RF and ANA are typically negative. * **Anti-Borrelia antibodies:** Used to diagnose Lyme disease. While Lyme can cause arthritis (usually a large joint like the knee), it does not typically cause urethritis, sacroiliitis, or circinate balanitis. **High-Yield Clinical Pearls for NEET-PG:** * **Mnemonic for Spondyloarthropathies (PEAR):** **P**soriatic arthritis, **E**nteropathic arthritis, **A**nkylosing spondylitis, **R**eactive arthritis. All are linked to HLA-B27. * **Keratoderma Blennorrhagicum:** Hyperkeratotic skin lesions on palms/soles, pathognomonic for Reactive Arthritis [3]. * **Cardiac involvement:** Aortitis leading to aortic regurgitation and conduction defects (heart block) are rare but high-yield complications. * **Treatment:** NSAIDs are first-line; antibiotics treat the underlying infection but do not usually resolve the arthritis once it has started.

Question 35: Which of the following statements is FALSE about reactive arthritis?

A. Most common among young men
B. Linked to HLA-B27
C. Painful asymmetric oligoarthritis is a feature
D. Migratory polyarthritis (Correct Answer)

Explanation: **Explanation:** Reactive arthritis (formerly Reiter’s Syndrome) is an **asymmetric inflammatory oligoarthritis** that develops following an extra-articular infection, typically of the gastrointestinal (e.g., *Salmonella, Shigella, Campylobacter*) or genitourinary tract (e.g., *Chlamydia trachomatis*) [1]. **Why Option D is the correct (False) statement:** Reactive arthritis characteristically presents as an **additive, asymmetric oligoarthritis** (affecting 2–4 joints), primarily involving the large weight-bearing joints of the lower extremities (knees and ankles) [1]. **Migratory polyarthritis** is a classic feature of **Acute Rheumatic Fever** or disseminated gonococcal infection, not reactive arthritis. **Analysis of other options:** * **Option A:** It is most common among young men (aged 20–40), particularly the post-venereal form associated with *Chlamydia* [1]. * **Option B:** There is a strong genetic predisposition; approximately **30–50%** of patients are **HLA-B27 positive** [1]. This association is even stronger in patients with sacroiliitis or uveitis. * **Option C:** The hallmark clinical presentation is a painful, asymmetric oligoarthritis, often accompanied by enthesitis (e.g., Achilles tendonitis) and dactylitis ("sausage digits") [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Classic Triad:** "Can't see (Uveitis/Conjunctivitis), can't pee (Urethritis), can't climb a tree (Arthritis)" [1]. * **Dermatological findings:** Look for **Keratoderma blennorrhagicum** (vesicular/pustular lesions on palms/soles) and **Circinate balanitis** [1]. * **Synovial Fluid:** Culture is typically **negative** (hence "reactive"), distinguishing it from septic arthritis. * **Treatment:** NSAIDs are first-line; antibiotics treat the triggering infection but do not usually resolve the arthritis itself.

Question 36: Which of the following is NOT a minor Jones criterion?

A. Arthralgia
B. Fever
C. Prolonged PR interval
D. Chorea (Correct Answer)

Explanation: The **Jones Criteria** are used to diagnose the first episode of **Acute Rheumatic Fever (ARF)**, a non-suppurative sequela of Group A Streptococcal (GAS) pharyngitis [1]. The criteria are divided into Major and Minor categories based on their diagnostic specificity. ### Why Chorea is the Correct Answer **Chorea (Sydenham’s Chorea)** is a **Major Jones Criterion**, not a minor one. It is characterized by rapid, purposeless, involuntary movements and emotional lability [1]. It often has a long latent period (months) after the initial infection and can be the sole manifestation of ARF. ### Explanation of Incorrect Options (Minor Criteria) The following are classified as **Minor Criteria** because they are non-specific and can occur in many inflammatory conditions: * **A. Arthralgia:** Joint pain without objective findings (swelling or redness). Note: If polyarthritis is used as a major criterion, arthralgia cannot be counted as a minor criterion. * **B. Fever:** Usually $\geq 38.5^\circ\text{C}$ in low-risk populations [2]. * **C. Prolonged PR interval:** Evidence of first-degree heart block on ECG (unless carditis is used as a major criterion). * *Other Minor Criteria include elevated acute phase reactants (ESR $\geq 60$ mm/hr or CRP $\geq 3.0$ mg/dL).* ### NEET-PG High-Yield Pearls * **Diagnosis Requirement:** 2 Major OR 1 Major + 2 Minor criteria, **PLUS** evidence of preceding GAS infection (e.g., elevated ASO titer, positive throat culture, or Rapid Antigen Test) [1]. * **Mnemonic for Major Criteria (J♥NES):** * **J** - Joints (Migratory Polyarthritis) * **♥** - Carditis (Pancarditis) [1] * **N** - Nodules (Subcutaneous) * **E** - Erythema Marginatum * **S** - Sydenham’s Chorea * **Most Common Manifestation:** Arthritis. * **Most Serious Manifestation:** Carditis (can lead to chronic Rheumatic Heart Disease, most commonly affecting the **Mitral Valve**).

Question 37: HLA-B27 antigen is associated with all of the following conditions except?

A. Ankylosing spondylitis
B. Reiter's syndrome
C. Psoriatic arthropathy
D. Rheumatoid arthritis (Correct Answer)

Explanation: **Explanation:** The association between HLA-B27 and specific inflammatory conditions is a classic high-yield topic in Rheumatology. HLA-B27 is a Class I surface antigen of the Major Histocompatibility Complex (MHC) strongly linked to the **Seronegative Spondyloarthropathies (SpA)** [1]. **Why Rheumatoid Arthritis (Option D) is the correct answer:** Rheumatoid Arthritis (RA) is **not** part of the Seronegative Spondyloarthropathy group. Instead of HLA-B27, RA is strongly associated with **HLA-DR4** (specifically the "shared epitope" on the DRB1 allele). RA is characterized by symmetric small joint involvement and the presence of Rheumatoid Factor (RF) or Anti-CCP antibodies, whereas HLA-B27-associated diseases are typically RF-negative. **Analysis of Incorrect Options (HLA-B27 Associated):** The mnemonic **"PEAR"** is commonly used to remember the Seronegative Spondyloarthropathies associated with HLA-B27: * **Psoriatic arthropathy (Option C):** Approximately 40-50% of patients with axial involvement are HLA-B27 positive [1]. * **Enteropathic arthritis:** Associated with Inflammatory Bowel Disease (UC/Crohn’s). * **Ankylosing spondylitis (Option A):** Has the strongest association; >90% of patients are HLA-B27 positive [1]. * **Reiter's syndrome / Reactive Arthritis (Option B):** Typically follows a GI or GU infection; 60-80% association with HLA-B27 [1]. **NEET-PG Clinical Pearls:** 1. **Strongest Association:** Ankylosing Spondylitis has the highest correlation with HLA-B27 (>90%) [1]. 2. **Common Features:** These conditions share clinical features like sacroiliitis, enthesitis (inflammation at tendon insertion sites), and uveitis [1]. 3. **HLA-DR4:** Always remember DR4 for Rheumatoid Arthritis to differentiate it from the B27 group. 4. **B27 Subtypes:** While there are many subtypes, **B*2705** is the most common globally associated with disease.

Question 38: Which of the following are characteristics of Sjögren's syndrome?

A. Dry eyes
B. Dry mouth
C. Rheumatoid arthritis
D. All of the above (Correct Answer)

Explanation: Sjögren's syndrome (SS) is a chronic, systemic autoimmune disorder characterized by lymphocytic infiltration of exocrine glands, primarily the lacrimal and salivary glands. 1. **Dry Eyes (Keratoconjunctivitis Sicca):** Lymphocytic infiltration leads to decreased tear production [1]. Patients often complain of a "gritty" or "sandy" sensation in the eyes. 2. **Dry Mouth (Xerostomia):** Reduced salivary flow leads to difficulty swallowing dry food, dental caries, and oral candidiasis. 3. **Rheumatoid Arthritis (RA):** Sjögren's syndrome is classified into two types: * **Primary SS:** Occurs in isolation. * **Secondary SS:** Occurs in association with another autoimmune disease, most commonly **Rheumatoid Arthritis** [1], but also SLE or Scleroderma. Since Sjögren's syndrome encompasses both the "sicca complex" (dry eyes/mouth) and can frequently occur secondary to Rheumatoid Arthritis, **Option D (All of the above)** is the correct answer. **High-Yield Clinical Pearls for NEET-PG:** * **Antibodies:** Anti-Ro (SS-A) and Anti-La (SS-B) are the most specific markers. * **Diagnosis:** The **Schirmer’s test** measures tear production (positive if <5mm in 5 mins). The gold standard for diagnosis is a **minor salivary gland biopsy** showing lymphocytic aggregates (Focus score ≥1). * **Malignancy Risk:** Patients with Sjögren's have a 40-fold increased risk of developing **B-cell Non-Hodgkin Lymphoma** (MALToma). * **Extraglandular features:** May include Raynaud’s phenomenon, cutaneous vasculitis, and interstitial nephritis.

Question 39: Palpable purpura is seen in which of the following conditions?

A. Idiopathic thrombocytopenic purpura (ITP)
B. Scurvy
C. Henoch-Schönlein Purpura (Correct Answer)
D. Monoclonal cryoglobulinemia

Explanation: The hallmark of **small-vessel vasculitis** is **palpable purpura**. This occurs because inflammation of the vessel wall (vasculitis) leads to increased vascular permeability and the extravasation of red blood cells into the dermis. Unlike simple hemorrhages, the associated inflammatory edema and cellular infiltrate make the lesions elevated and palpable. **1. Why Henoch-Schönlein Purpura (HSP) is correct:** HSP (now termed IgA Vasculitis) is a systemic small-vessel vasculitis characterized by the deposition of **IgA-dominant immune complexes**. It typically presents with the classic tetrad of palpable purpura (usually on the lower extremities/buttocks), arthralgia, abdominal pain, and renal involvement (hematuria). **2. Why the other options are incorrect:** * **Idiopathic Thrombocytopenic Purpura (ITP):** This is caused by a low platelet count. Thrombocytopenic purpura is **non-palpable (flat)** because there is no underlying vessel wall inflammation or edema. * **Scurvy (Vitamin C deficiency):** Presents with "perifollicular hemorrhages" and corkscrew hairs. While the skin lesions are distinct, they are due to defective collagen synthesis leading to capillary fragility, not vasculitis; hence, they are generally not considered "palpable purpura." * **Monoclonal Cryoglobulinemia (Type I):** This typically causes hyperviscosity and vascular occlusion, leading to Raynaud’s phenomenon or digital ischemia. **Mixed Cryoglobulinemia (Types II and III)** is what typically causes small-vessel vasculitis and palpable purpura. **High-Yield Clinical Pearls for NEET-PG:** * **Rule of Thumb:** If purpura is palpable, think **Vasculitis** (e.g., HSP, Microscopic Polyangiitis). If purpura is flat/non-palpable, think **Platelet disorders** (ITP) or **Vascular fragility** (Senile purpura, Scurvy). * **HSP Trigger:** Often follows an Upper Respiratory Tract Infection (URTI). * **Biopsy:** Skin biopsy in HSP shows **Leukocytoclastic vasculitis** with IgA deposits on immunofluorescence.

Question 40: In a case of undifferentiated arthritis, the presence of anti-cyclic citrullinated peptide (anti-CCP) antibodies strongly indicates the possibility of which of the following conditions?

A. Rheumatoid arthritis (Correct Answer)
B. Systemic lupus erythematosus
C. Mixed connective tissue disorder
D. Reactive arthritis

Explanation: The presence of **anti-cyclic citrullinated peptide (anti-CCP)** antibodies in a patient with undifferentiated arthritis is highly predictive of **Rheumatoid Arthritis (RA)**. 1. **Why Rheumatoid Arthritis is correct:** Anti-CCP antibodies are produced against proteins containing citrulline, an amino acid formed by the post-translational modification of arginine [3]. While Rheumatoid Factor (RF) is sensitive, it lacks specificity. In contrast, anti-CCP has a **specificity of >95%** for RA. Its presence in early or undifferentiated arthritis is a strong predictor of progression to erosive RA and is now included in the **ACR/EULAR 2010 classification criteria**. 2. **Why the other options are incorrect:** * **Systemic Lupus Erythematosus (SLE):** The hallmark autoantibody is **Anti-dsDNA** (specific) and ANA (sensitive). While SLE can cause arthritis, anti-CCP is rarely positive unless there is "Rhupus" overlap [1]. * **Mixed Connective Tissue Disorder (MCTD):** This is characterized specifically by high titers of **Anti-U1 RNP** antibodies [1]. * **Reactive Arthritis:** This is a seronegative spondyloarthropathy. It is typically associated with **HLA-B27** and occurs following a gastrointestinal or urogenital infection; autoantibodies like anti-CCP are absent. **High-Yield Pearls for NEET-PG:** * **Most Specific Marker for RA:** Anti-CCP (Anti-citrullinated protein antibody/ACPA). * **Best Initial Test for RA:** Rheumatoid Factor (RF). * **Prognostic Value:** High titers of anti-CCP correlate with a higher risk of **radiographic joint damage** and extra-articular manifestations [2]. * **Smoking Link:** Smoking is a major environmental risk factor that promotes the citrullination of proteins in the lungs, triggering anti-CCP production in genetically susceptible individuals (HLA-DRB1 "shared epitope").

Practice by Chapter

Rheumatoid Arthritis

Practice Questions

Spondyloarthropathies

Practice Questions

Systemic Lupus Erythematosus

Practice Questions

Vasculitis Syndromes

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Scleroderma and Related Disorders

Practice Questions

Inflammatory Myopathies

Practice Questions

Crystal Arthropathies

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Osteoarthritis

Practice Questions

Primary Immunodeficiency Disorders

Practice Questions

Autoinflammatory Syndromes

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Sjögren's Syndrome

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Antiphospholipid Syndrome

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