A 19-year-old engineering student is admitted with meningococcal meningitis, confirmed by culture. Two years ago he had meningococcal septicaemia. He has no other history of infection, and HIV test and immunoglobulin levels are normal. Which test should be done next to look for the underlying defect?

CH50 (total haemolytic complement) assay

A 19-year-old girl has had several episodes of non-itchy swelling of the lips, hands and once the larynx, each lasting 2-4 days, with no wheals. Antihistamines and steroids did not help. Her father has similar episodes. Which is the best screening blood test?

CH50 (total haemolytic complement)

Rheumatology and connective tissue disease

22 NEET-PG practice questions on Rheumatology and connective tissue disease, part of General Medicine. The first 22 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Medium
A 23-year-old woman from Lucknow has had fatigue and aching of the left arm on use for 6 months. The left radial pulse is feeble, BP is 150/90 mmHg in the right arm and 104/70 mmHg in the left, and a bruit is heard over the left subclavian artery and the abdomen. ESR is 48 mm/h. What is the most likely diagnosis?
1. APolyarteritis nodosa
2. BFibromuscular dysplasia
3. CTakayasu arteritis
4. DCoarctation of the aorta
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Answer: C · Takayasu arteritis
A young woman with limb claudication, an absent or weak pulse, a BP difference between the arms and arterial bruits has Takayasu arteritis, a granulomatous large-vessel vasculitis of the aorta and its main branches that is relatively common in India and other Asian countries. Indian patients often have abdominal aortic and renal artery disease, which causes renovascular hypertension. CT or MR angiography shows stenoses and wall thickening. Treatment is with glucocorticoids and a steroid-sparing agent, with revascularisation for critical stenoses once inflammation settles.
- A: PAN affects medium arteries of gut, kidney and nerves and does not cause pulselessness of the arm.
- B: Fibromuscular dysplasia is non-inflammatory and mainly affects renal and carotid arteries, without a raised ESR.
- D: Coarctation causes upper-limb hypertension with weak femoral pulses, not an arm-to-arm difference with a raised ESR.
Question 2 · Medium
A 19-year-old engineering student is admitted with meningococcal meningitis, confirmed by culture. Two years ago he had meningococcal septicaemia. He has no other history of infection, and HIV test and immunoglobulin levels are normal. Which test should be done next to look for the underlying defect?
1. ACH50 (total haemolytic complement) assay
2. BSerum IgG subclass levels
3. CCD4 and CD8 counts
4. DNitroblue tetrazolium test
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Answer: A · CH50 (total haemolytic complement) assay
Recurrent Neisseria infection, especially meningococcal disease, is the hallmark of deficiency of the terminal complement components C5-C9, which form the membrane attack complex needed to lyse Neisseria. Properdin deficiency gives a similar picture. The CH50 assay screens the classical pathway and is very low or absent in terminal component deficiency; individual components are measured afterwards. Patients need meningococcal vaccination, and close relatives should be tested.
- B: IgG subclass deficiency causes recurrent sinopulmonary infections, not repeated meningococcal disease.
- C: T-cell counts screen for cellular immunodeficiency, which causes viral and fungal infections.
- D: The NBT test screens for chronic granulomatous disease, which causes catalase-positive infections.
Question 3 · Easy
A 19-year-old girl has had several episodes of non-itchy swelling of the lips, hands and once the larynx, each lasting 2-4 days, with no wheals. Antihistamines and steroids did not help. Her father has similar episodes. Which is the best screening blood test?
1. ASerum total IgE
2. BSerum C4 level
3. CSerum tryptase
4. DCH50 (total haemolytic complement)
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Answer: B · Serum C4 level
Recurrent angioedema without urticaria, unresponsive to antihistamines and steroids, with an autosomal dominant family history suggests hereditary angioedema from C1 esterase inhibitor deficiency. Uncontrolled activation of the classical pathway consumes C4, so a low C4 is the best screening test, and it is usually low even between attacks. The diagnosis is confirmed by a low C1-inhibitor level (type 1) or low C1-inhibitor function (type 2). The swelling is driven by bradykinin, not histamine.
- A: IgE is raised in allergy, which gives itchy urticaria and responds to antihistamines.
- C: Tryptase rises in mast-cell (anaphylactic) reactions, not bradykinin angioedema.
- D: CH50 screens for complement deficiency in general but is less specific for C1-inhibitor deficiency.
Question 4 · Medium
A 24-year-old woman with SLE (malar rash, arthritis, ANA and anti-dsDNA positive) has new pedal oedema. BP 150/96 mmHg, urine protein 3+, urine microscopy shows dysmorphic RBCs and RBC casts, 24-hour urine protein 2.8 g, serum creatinine 1.4 mg/dL, C3 and C4 low. Which investigation will best guide her treatment?
1. AAnti-dsDNA titre
2. BRenal biopsy
3. CSerum cystatin C
4. DRenal Doppler ultrasound
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Answer: B · Renal biopsy
Active sediment, proteinuria and rising creatinine in SLE mean lupus nephritis. A renal biopsy is needed because the histological class (ISN/RPS) and the activity and chronicity indices decide therapy: proliferative nephritis (class III or IV) needs induction with glucocorticoids plus mycophenolate or cyclophosphamide, while other classes are managed differently. Biopsy also excludes other causes such as thrombotic microangiopathy from antiphospholipid antibodies. All patients receive hydroxychloroquine and blood-pressure control with an ACE inhibitor or ARB.
- A: Anti-dsDNA tracks activity but cannot show the class or chronicity of nephritis.
- C: Cystatin C estimates GFR but does not classify the lesion.
- D: Doppler ultrasound shows renal size and vessels, not glomerular pathology.
Question 5 · Easy
Which autoantibody is the most specific for systemic lupus erythematosus?
1. AAnti-Ro (SS-A) antibody
2. BAnti-histone antibody
3. CAntinuclear antibody
4. DAnti-Smith antibody
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Answer: D · Anti-Smith antibody
Anti-Sm antibodies, directed against small nuclear ribonucleoproteins, are almost exclusive to SLE but are present in only about a quarter to a third of patients. Anti-dsDNA is also highly specific, and its titre rises with disease activity, especially nephritis. ANA is the most sensitive test (positive in nearly all patients) and is used for screening, not confirmation. A negative ANA makes SLE very unlikely.
- A: Anti-Ro occurs in Sjogren syndrome and subacute cutaneous and neonatal lupus.
- B: Anti-histone antibodies are typical of drug-induced lupus.
- C: ANA is the most sensitive test, but it is found in many other conditions.
Question 6 · Easy
A 24-year-old man has had low back pain for a year. It is worst in the early morning with stiffness for over an hour, wakes him in the second half of the night and eases with exercise but not rest. Chest expansion is reduced. In this disease, which joints show the earliest radiographic changes?
1. AHip joints
2. BLumbar facet joints
3. CSacroiliac joints
4. DCostovertebral joints
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Question 7 · Hard
A 21-year-old man has had recurrent swelling of the hands, face and once the throat since adolescence, and two episodes of severe colicky abdominal pain with vomiting. His mother has the same problem; his C4 is low. Consider these statements about his condition: 1. It is usually inherited as an autosomal dominant trait. 2. Attacks do not respond to antihistamines or steroids. 3. Itchy wheals usually accompany the swelling. 4. Icatibant, a bradykinin B2 receptor antagonist, can treat an acute attack. Which statements are correct?
1. A1 and 2 only
2. B2, 3 and 4 only
3. C1, 2, 3 and 4
4. D1, 2 and 4 only
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Question 8 · Medium
A 44-year-old man with scaly plaques on both elbows for 10 years now has painful swelling of the distal interphalangeal joints of several fingers and a sausage-shaped right second toe. His nails show pitting and onycholysis. Rheumatoid factor and anti-CCP are negative. Which X-ray finding is most typical of his condition?
1. APeriarticular osteopenia with MCP erosions
2. BHeberden's nodes with joint-space narrowing
3. CPunched-out erosions with overhanging edges
4. DPencil-in-cup deformity of the DIP joints
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Question 9 · Easy
A 38-year-old schoolteacher from Thrissur has had pain and swelling of both wrists and several MCP and PIP joints for 4 months, with morning stiffness lasting about 2 hours. Rheumatoid factor is weakly positive. Which antibody is most specific for her likely diagnosis?
1. AAnti-histone antibody
2. BAntinuclear antibody
3. CIgM rheumatoid factor
4. DAnti-CCP antibody
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Question 10 · Hard
A 27-year-old woman with SLE on prednisolone 10 mg and mycophenolate is admitted with fever of 38.9°C and joint pains for 4 days. The team must decide between a lupus flare and an infection. Consider these results: 1. C3 and C4 have fallen since her last visit. 2. Anti-dsDNA titre has doubled. 3. CRP is 140 mg/L (normal below 5) with no serositis. 4. WBC 2,600/µL with lymphocytes 500/µL. Which results favour a lupus flare?
1. A1, 2 and 3 only
2. B1, 2, 3 and 4
3. C1 and 2 only
4. D1, 2 and 4 only
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Question 11 · Hard
A 45-year-old truck driver has had weight loss, fever, calf pain and a right foot drop for 2 months, then left wrist drop. He has testicular pain, livedo reticularis and new hypertension of 170/100 mmHg. Creatinine 1.8 mg/dL, urine shows mild proteinuria without RBC casts, HBsAg is positive and ANCA is negative. Chest X-ray is clear. Which investigation is most likely to confirm the diagnosis without a tissue biopsy?
1. AHigh-resolution CT of the chest
2. BMesenteric and renal angiography
3. CNerve conduction study alone
4. DAnti-GBM antibody assay
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Question 12 · Medium
A 46-year-old man on isoniazid-containing treatment for pulmonary TB for 5 months develops fever, joint pains and pleuritic chest pain with a small pleural effusion. ANA is positive, anti-dsDNA negative, complement normal, urine normal. Which antibody would best support the likely diagnosis?
1. AAnti-Jo-1 antibody
2. BAnti-centromere antibody
3. CAnti-Smith antibody
4. DAnti-histone antibody
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Question 13 · Medium
A 74-year-old woman develops a painful, warm, swollen right knee on the second day after surgery for a fractured neck of femur. Temperature 38.1°C. Knee X-ray shows linear calcification of the menisci. Synovial fluid has 18,000 WBC/µL, Gram stain shows no organisms, and polarised microscopy shows rhomboid, weakly positively birefringent crystals. What is the most likely diagnosis?
1. ASeptic arthritis of the knee
2. BCalcium pyrophosphate arthritis
3. CHaemarthrosis after the fall
4. DAcute gouty arthritis
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Question 14 · Hard
A 30-year-old primigravida at 18 weeks attends the antenatal clinic. For 2 years she has had gritty dry eyes and needs water to swallow dry food; Schirmer test is positive. She is ANA positive with anti-Ro (SS-A) and anti-La (SS-B) antibodies. Which fetal complication should be specifically watched for with serial fetal echocardiography?
1. ACongenital complete heart block
2. BFetal supraventricular tachycardia
3. CTransposition of the great arteries
4. DEbstein anomaly
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Question 15 · Medium
A 58-year-old man with recurrent gout takes allopurinol 300 mg daily. He is started on azathioprine 100 mg daily for autoimmune hepatitis. Three weeks later he has fever and mouth ulcers; haemoglobin 7.8 g/dL, WBC 1,100/µL and platelets 42,000/µL. What explains this toxicity?
1. AAllopurinol displaced azathioprine from albumin
2. BAzathioprine induced allopurinol metabolism
3. CAllopurinol blocked the breakdown of azathioprine
4. DBoth drugs cause marrow aplasia by an immune reaction
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Question 16 · Medium
A 47-year-old man has had blood-stained nasal discharge and sinus pain for 3 months, and now has cough with haemoptysis. Chest X-ray shows multiple nodules, some cavitating. Urine shows RBC casts; serum creatinine has risen from 1.0 to 2.6 mg/dL in 2 weeks. Which antibody test is most likely to be positive?
1. Ap-ANCA against myeloperoxidase
2. BAnti-dsDNA antibody
3. CAnti-glomerular basement membrane antibody
4. Dc-ANCA against proteinase 3
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Question 17 · Medium
A 72-year-old retired teacher has had a new headache over the right temple for 3 weeks, pain in the jaw while chewing and aching stiffness of both shoulders. This morning she had a brief blurring of vision in the right eye. The right temporal artery is tender with a weak pulse. ESR is 96 mm/h. What is the next best step?
1. ARefer for MRI brain with contrast
2. BStart aspirin and review with ESR in a week
3. CStart high-dose glucocorticoids today
4. DArrange temporal artery biopsy before any treatment
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Question 18 · Medium
A 62-year-old woman with rheumatoid arthritis has taken methotrexate 15 mg once weekly for 3 years. A local practitioner prescribed cotrimoxazole for a urinary infection 10 days ago. She now has painful mouth ulcers, fever and bruising; haemoglobin 8.2 g/dL, WBC 900/µL and platelets 30,000/µL. Besides stopping both drugs, which drug should be given?
1. ACyanocobalamin
2. BFolinic acid
3. CFilgrastim alone
4. DFolic acid
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Question 19 · Medium
A 29-year-old woman has had three consecutive miscarriages before 10 weeks and a left leg DVT last year. Her aPTT is prolonged and does not correct on mixing with normal plasma; lupus anticoagulant and anticardiolipin IgG are positive on two occasions 12 weeks apart. She is now 6 weeks pregnant. What is the best management?
1. ARivaroxaban throughout pregnancy
2. BTherapeutic LMWH with low-dose aspirin
3. CLow-dose aspirin alone
4. DWarfarin with low-dose aspirin
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Question 20 · Easy
A 52-year-old businessman wakes at 3 a.m. after a wedding feast with excruciating pain, redness and swelling of the right first metatarsophalangeal joint; even the bedsheet hurts. The joint is aspirated in casualty. What will polarised light microscopy of the fluid most likely show?
1. AFlat, notched rectangular plates
2. BNeedle-shaped, strongly negatively birefringent crystals
3. CMaltese-cross shaped lipid droplets
4. DRhomboid, weakly positively birefringent crystals
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Question 21 · Medium
A 26-year-old man comes to the OPD with a painful swollen left knee and right ankle and pain in both heels. Three weeks ago he had bloody diarrhoea that settled on its own. He has red eyes and painless shallow ulcers around the urethral meatus. Joint fluid culture is sterile. What is the most likely diagnosis?
1. AReactive arthritis
2. BEnteropathic arthritis of ulcerative colitis
3. CSeptic arthritis
4. DDisseminated gonococcal infection
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Question 22 · Hard
A 36-year-old woman with diffuse cutaneous systemic sclerosis diagnosed 8 months ago (anti-RNA polymerase III positive) was started on prednisolone 40 mg daily for myositis 3 weeks ago. She now has severe headache and blurred vision. BP 210/124 mmHg; creatinine has risen from 0.8 to 2.9 mg/dL; haemoglobin 9.1 g/dL with schistocytes on the smear and platelets 82,000/µL. Which drug is the cornerstone of treatment?
1. AAmlodipine
2. BIntravenous labetalol
3. CIntravenous methylprednisolone
4. DCaptopril
Answer and explanation in LearnFree account

Rheumatology and connective tissue disease

A 19-year-old girl has had several episodes of non-itchy swelling of the lips, hands and once the larynx, each lasting 2-4 days, with no wheals. Antihistamines and steroids did not help. Her father has similar episodes. Which is the best screening blood test?

Which autoantibody is the most specific for systemic lupus erythematosus?

A 24-year-old man has had low back pain for a year. It is worst in the early morning with stiffness for over an hour, wakes him in the second half of the night and eases with exercise but not rest. Chest expansion is reduced. In this disease, which joints show the earliest radiographic changes?

A 38-year-old schoolteacher from Thrissur has had pain and swelling of both wrists and several MCP and PIP joints for 4 months, with morning stiffness lasting about 2 hours. Rheumatoid factor is weakly positive. Which antibody is most specific for her likely diagnosis?

A 46-year-old man on isoniazid-containing treatment for pulmonary TB for 5 months develops fever, joint pains and pleuritic chest pain with a small pleural effusion. ANA is positive, anti-dsDNA negative, complement normal, urine normal. Which antibody would best support the likely diagnosis?

A 58-year-old man with recurrent gout takes allopurinol 300 mg daily. He is started on azathioprine 100 mg daily for autoimmune hepatitis. Three weeks later he has fever and mouth ulcers; haemoglobin 7.8 g/dL, WBC 1,100/µL and platelets 42,000/µL. What explains this toxicity?

A 52-year-old businessman wakes at 3 a.m. after a wedding feast with excruciating pain, redness and swelling of the right first metatarsophalangeal joint; even the bedsheet hurts. The joint is aspirated in casualty. What will polarised light microscopy of the fluid most likely show?