LE5 Flashcards

Question

**41. The most frequently affected joints in rheumatoid arthritis are:** A. Wrist B. Distal interphalangeal joints (DIP) C. Proximal interphalangeal joints (PIP) D. Metacarpophalangeal joints (MCP)

Answer 1

D. Metacarpophalangeal joints (MCP) 💡 Rationale: RA primarily affects small joints, especially MCP, PIP, and wrist joints, sparing DIP joints (which are more affected in osteoarthritis).

Answer 2

A. Flexor tenosynovitis 💡 Rationale: Flexor tenosynovitis is a hallmark of RA, leading to stiffness, reduced grip strength, and trigger fingers. Dactylitis, enthesitis, and sacroiliitis are seen in spondyloarthropathies, not RA.

Answer 3

C. Vasculitis 💡 Rationale: RA-associated vasculitis can cause systemic inflammation, fever, and skin ulcers. Pericarditis and pleuritis are common but do not typically cause high fever. Felty’s syndrome presents with neutropenia and splenomegaly, not fever.

Answer 4

B. Normocytic normochromic anemia 💡 Rationale: Anemia of chronic disease (normocytic, normochromic) is the most common hematologic abnormality in RA. Neutropenia is seen in Felty’s syndrome, while leukemia and lymphoma are not primary findings.

Answer 5

B. Increase in length by 4 cm or less 💡 Rationale: A Modified Schober Test increase of ≤4 cm suggests reduced lumbar spinal mobility, a hallmark of ankylosing spondylitis (AS). A normal response is >5 cm.

Answer 6

A. Axial symptoms predominate 💡 Rationale: In juvenile spondyloarthritis (JSpA), peripheral arthritis and enthesitis are more common than axial symptoms, which tend to appear later in adolescence.

Answer 7

C. Low histologic grade 💡 Rationale: High-grade lymphomas are associated with worse prognosis in Sjögren’s syndrome-associated lymphoma. Poor prognostic indicators include lymph node mass >10 cm, B symptoms (fever, weight loss, night sweats), and high histologic grade.

Answer 8

A. True 💡 Rationale: Sjögren’s syndrome causes non-erosive arthritis, meaning it does not destroy joint surfaces. However, it may lead to Jaccoud’s arthropathy, a deforming but non-erosive hand arthritis similar to SLE.

Answer 9

B. Colchicine treatment 💡 Rationale: Colchicine is used for gout treatment and prevention, not as a trigger. Common triggers include dietary excess (purine-rich foods), alcohol, surgery/trauma, and dehydration.

Answer 10

B. Aspiration of joint fluid 💡 Rationale: Synovial fluid aspiration is the gold standard for diagnosing gout by identifying negatively birefringent, needle-shaped monosodium urate crystals. Imaging studies (X-ray, CT, ultrasound) are supportive but not diagnostic.

Answer 11

C. Diuretics 💡 Rationale: Thiazide and loop diuretics decrease uric acid excretion, increasing serum urate levels and precipitating gout attacks. Beta-blockers, ACE inhibitors, and nitrates do not directly trigger gout.

Answer 12

A. Chronic gout 💡 Rationale: Calcium pyrophosphate deposition disease (CPPD, pseudogout) is associated with hypomagnesemia, hyperparathyroidism, and epiphyseal dysplasia, not chronic gout. Gout involves monosodium urate crystals, not CPPD.

Answer 13

A. Knee 💡 Rationale: The knee is the most commonly involved joint in CPPD (pseudogout). The wrist and metacarpophalangeal (MCP) joints are less frequently involved.

Answer 14

D. Hyperthyroidism 💡 Rationale: Apatite deposition disease (e.g., hydroxyapatite arthritis) is linked to hyperparathyroidism, renal failure (milk-alkali syndrome), and connective tissue diseases like systemic sclerosis. Hyperthyroidism is not a known association.

Answer 15

A. Ascorbic acid 💡 Rationale: Vitamin C (ascorbic acid) is metabolized to oxalate, which can lead to oxalate nephropathy and nephrolithiasis in patients with renal failure. Pyridoxine, cholecalciferol, and alpha-tocopherol do not pose this risk.

Answer 16

B. Thick and indurated skin (scleroderma) 💡 Rationale: Scleroderma (thickened, indurated skin) is the hallmark of systemic sclerosis. Joint contractures, interstitial lung disease, and digital ulcers are common but not the defining feature.

Answer 17

B. Raynaud's phenomenon precedes other disease manifestations. 💡 Rationale: Limited cutaneous systemic sclerosis (lcSSc) typically begins with Raynaud's phenomenon, which may precede other symptoms by years. Unlike diffuse SSc (dcSSc), skin involvement remains limited to the face, hands, and forearms.

Answer 18

A. Calcinosis cutis 💡 Rationale: CREST syndrome (a subset of limited systemic sclerosis) includes: Calcinosis cutis Raynaud's phenomenon Esophageal dysmotility Sclerodactyly Telangiectasia

Answer 19

D. Welding fumes 💡 Rationale: Organic solvents, epoxy resin, and hydrocarbons are linked to systemic sclerosis. Welding fumes are not a recognized environmental trigger.

Answer 20

D. Appetite stimulants 💡 Rationale: Appetite suppressants (e.g., fenfluramine) are linked to systemic sclerosis-like conditions, not appetite stimulants. Bleomycin, pentazocine, and cocaine are also implicated.

Answer 21

D. Atherosclerosis 💡 Rationale: Systemic sclerosis is characterized by diffuse microangiopathy, immune dysregulation, and visceral/vascular fibrosis, but not atherosclerosis. Vascular occlusion in SSc is due to fibrosis, not lipid-driven atherosclerosis.

Answer 22

A. Nonspecific interstitial pneumonia (NSIP) 💡 Rationale: NSIP is the most common lung pathology in systemic sclerosis, followed by usual interstitial pneumonia (UIP/pulmonary fibrosis). Pulmonary arterial hypertension (PAH) is also common but is a vascular complication.

Answer 23

A. Raynaud's phenomenon 💡 Rationale: Raynaud’s phenomenon is present in almost 90% of systemic sclerosis cases, making it the most frequent extracutaneous manifestation.

Answer 24

D. Hypothyroidism from Graves' or Hashimoto's disease is common. 💡 Rationale: Thyroid dysfunction is not commonly associated with systemic sclerosis. However, sicca symptoms (dry eyes, dry mouth), erectile dysfunction, and impaired fertility are frequent.

Answer 25

C. Pulmonary arterial hypertension (PAH) 💡 Rationale: PAH is the leading cause of death in systemic sclerosis, followed by interstitial lung disease (ILD). Raynaud’s phenomenon and thromboembolism are complications but not primary causes of mortality.

Answer 26

A. Dermatomyositis 💡 Rationale: Dermatomyositis (DM) presents with a heliotrope rash, Gottron papules, and periungual telangiectasia. It is an autoimmune inflammatory myopathy associated with proximal muscle weakness and malignancies.

Answer 27

C. Antisynthetase syndrome 💡 Rationale: Antisynthetase syndrome (ASS) is an inflammatory myopathy characterized by Raynaud’s phenomenon, nonerosive arthritis, interstitial lung disease (ILD), mechanic’s hands, and myositis. Dermatomyositis and polymyositis can have arthritis but not as commonly with Raynaud’s.

Answer 28

D. None of the above (NOTA) 💡 Rationale: ILD is a common complication of dermatomyositis, polymyositis, and antisynthetase syndrome. Among them, antisynthetase syndrome has the strongest ILD association.

Answer 29

C. Inclusion body myositis 💡 Rationale: Inclusion body myositis (IBM) has been reported in association with Sjögren’s syndrome, while dermatomyositis, polymyositis, and antisynthetase syndrome are less frequently linked to Sjögren’s.

Answer 30

C. Inclusion body myositis 💡 Rationale: Granular lymphocytic leukemia (LGLL) has been associated with inclusion body myositis (IBM) and other autoimmune diseases like Sjögren’s syndrome and RA.

Answer 31

A. Antihistone 💡 Rationale: Antihistone antibodies are found in >90% of drug-induced lupus cases but are less common in idiopathic SLE. Anti-dsDNA and Anti-Sm are more specific for SLE.

Answer 32

A. Anti-dsDNA 💡 Rationale: Anti-dsDNA antibodies are highly specific for SLE and correlate with disease activity, lupus nephritis, and vasculitis.

Answer 33

D. Antiphospholipid 💡 Rationale: Antiphospholipid antibodies (APL) are associated with thrombosis, recurrent fetal loss, and thrombocytopenia, leading to antiphospholipid syndrome (APS).

Answer 34

A. Nonspecific interstitial pneumonia (NSIP) 💡 Rationale: NSIP is the most common pulmonary manifestation in systemic sclerosis, followed by UIP (pulmonary fibrosis). Pulmonary arterial hypertension (PAH) is a leading cause of mortality but is a vascular complication, not an ILD pattern.

Answer 35

C. All of the above 💡 Rationale: Antiphospholipid syndrome (APS) and thrombotic thrombocytopenic purpura (TTP) can mimic vasculitis due to microvascular thrombosis and endothelial injury without true inflammation of vessel walls.

Answer 36

D. Nodular nontoxic goiter 💡 Rationale: Atrial myxoma, lymphoma, and carcinomatosis can produce vasculitis-like syndromes, including constitutional symptoms, embolic events, and immune complex deposition. Nodular goiter does not mimic vasculitis.

Answer 37

A. Necrotizing vasculitis of small arteries and veins with granuloma formation 💡 Rationale: Granulomatosis with polyangiitis (Wegener’s) is characterized by small-vessel necrotizing vasculitis with granulomatous inflammation, primarily affecting the lungs, kidneys, and upper respiratory tract.

Answer 38

B. Technetium 💡 Rationale: Amphetamines, arsenic, and ergot alkaloids can cause vasospasm, thrombosis, and necrotizing vasculopathy, mimicking vasculitis. Technetium (Tc) is used in imaging and does not cause vasculitis-like toxicity.

Answer 39

C. Tissue biopsy in a patient with compatible clinical features 💡 Rationale: Definitive diagnosis requires a biopsy demonstrating necrotizing granulomatous vasculitis. c-ANCA (PR3-ANCA) is highly specific but not diagnostic alone.

Answer 40

C. Subclavian artery 💡 Rationale: Takayasu arteritis primarily affects the aorta and its major branches, with the subclavian artery being most commonly involved, leading to upper limb claudication.

Answer 41

D. It is a pauci-immune vasculitis affecting medium and large-sized blood vessels → ❌ Incorrect, as GPA primarily affects small and medium-sized vessels, not large vessels.

Answer 42

B. Polyarteritis nodosa 💡 Rationale: Polyarteritis nodosa (PAN) is a classic medium-vessel vasculitis that spares capillaries and venules. It is not associated with ANCA and often involves renal, gastrointestinal, and peripheral nervous system vessels.

Answer 43

C. Giant cell arteritis 💡 Rationale: Giant cell arteritis (GCA), also called temporal arteritis, affects the branches of the external carotid artery and is characterized by headaches, jaw claudication, and vision loss.

Answer 44

D. Churg-Strauss Syndrome (Eosinophilic Granulomatosis with Polyangiitis - EGPA) 💡 Rationale: Eosinophilic Granulomatosis with Polyangiitis (EGPA, formerly Churg-Strauss Syndrome) is characterized by eosinophilia, asthma, allergic rhinitis, and vasculitis involving small to medium vessels.

Answer 45

B. Non-pharmacologic treatment is not effective for fibromyalgia. 💡 Rationale: Non-pharmacologic treatments such as exercise, cognitive-behavioral therapy (CBT), and sleep hygiene are effective in managing fibromyalgia. While medications like duloxetine and pregabalin help, a multimodal approach is most effective.

Answer 46

A. 4 kg/cm² 💡 Rationale: The standard pressure applied in a tender point examination is 4 kg/cm², which is equivalent to the pressure needed to blanch the examiner’s fingernail.

Answer 47

D. Infraspinatus 💡 Rationale: Tender points in fibromyalgia are symmetrical and located at specific muscle and tendon junctions. Common sites include the trapezius, upper outer gluteal area, and medial knee. The infraspinatus is NOT a standard tender point.

Answer 48

C. The old ACR criteria required 11 out of 18 tender points to make a diagnosis. 💡 Rationale: The 1990 ACR criteria required ≥11 out of 18 specified tender points to be present. The 2010 ACR criteria introduced the Widespread Pain Index (WPI) and Symptom Severity Score (SSS), requiring pain in at least 4 of 5 body regions.

Answer 49

C. Anticonvulsants such as pregabalin must be avoided. 💡 Rationale: Pregabalin and gabapentin are FDA-approved for fibromyalgia treatment due to their role in neuropathic pain modulation. Other treatment options include SNRIs (Duloxetine, Milnacipran) and Tricyclic Antidepressants (Amitriptyline), while glucocorticoids are ineffective.

Answer 50

A. Polyarthritis and carditis 💡 Rationale: Polyarthritis and carditis are the most common major manifestations of acute rheumatic fever (ARF). Other features like chorea and erythema marginatum are less common.

Answer 51

B. 1–5 weeks 💡 Rationale: Acute rheumatic fever typically occurs 1–5 weeks after a Group A streptococcal pharyngitis infection. Longer latent periods are rare.

Answer 52

B. Thick and indurated skin 💡 Rationale: Skin thickening (scleroderma) is the hallmark of systemic sclerosis, distinguishing it from other connective tissue diseases.

Answer 53

D. Raynaud’s phenomenon precedes other disease manifestations. 💡 Rationale: Raynaud’s phenomenon is often the first symptom in limited cutaneous systemic sclerosis (lcSSc) and may precede other symptoms by years.

Answer 54

D. Welding fumes 💡 Rationale: Exposure to organic solvents, aromatic hydrocarbons, and epoxy resins is associated with systemic sclerosis. Welding fumes are not a well-established risk factor.

Answer 55

A. Nonspecific interstitial pneumonia (NSIP) 💡 Rationale: NSIP is the most common interstitial lung disease (ILD) pattern seen in systemic sclerosis, followed by usual interstitial pneumonia (UIP).

Answer 56

C. Pulmonary arterial hypertension (PAH) 💡 Rationale: PAH is the leading cause of mortality in systemic sclerosis, followed by interstitial lung disease (ILD).

Answer 57

C. Proximal thickening of the skin 💡 Rationale: Proximal skin thickening extending beyond the fingers (proximal to the MCP joints) is a major diagnostic criterion for systemic sclerosis.

Answer 58

C. Raynaud’s Phenomenon 💡 Rationale: Raynaud’s phenomenon is characterized by triphasic color changes (white, blue, red) due to vasospasm and is a hallmark of systemic sclerosis.

Answer 59

A. Cyclophosphamide 💡 Rationale: Cyclophosphamide is the first-line treatment for interstitial lung disease (ILD) in systemic sclerosis, improving lung function and reducing fibrosis progression.

Answer 60

C. Raynaud’s phenomenon

Answer 61

D. Atherosclerosis 💡 Rationale: Systemic sclerosis is driven by diffuse microangiopathy, immune dysregulation, and fibrosis. Atherosclerosis is not a primary mechanism.

Answer 62

A. Management of symptoms without dialysis 💡 Rationale: Conservative management in CKD involves symptom control, lifestyle modifications, and medication use without dialysis or transplantation, often for patients who decline dialysis or are not candidates.

Answer 63

B. Moderate risk (yellow) 💡 Rationale: eGFR 48 mL/min/1.73m² falls in G3a (45-59 mL/min/1.73m²) UPCR (urine protein-to-creatinine ratio) = 100 mg/g falls in A1 (<150 mg/g, normal to mild albuminuria) According to KDIGO heatmap, this places the patient at moderate risk (yellow).

Answer 64

C. High risk (orange) 💡 Rationale: eGFR 46 mL/min/1.73m² → G3a CKD Albuminuria 100 mg/g → A2 CKD (Moderately increased albuminuria: 30-300 mg/g) According to the KDIGO heatmap, a combination of G3a + A2 places the patient in the "High risk" (orange) category.

Answer 65

A. 10 units of regular insulin IV and 50 mL of 50% dextrose 💡 Rationale: In hyperkalemia (K+ >6.5 mmol/L with ECG changes), immediate treatment includes: Insulin + dextrose (shifts K+ into cells) Calcium gluconate (stabilizes cardiac membranes) Beta-agonists (albuterol/salbutamol) Kayexalate (sodium polystyrene sulfonate) and dialysis for definitive K+ removal.

Answer 66

B. Low sodium diet 💡 Rationale: A low sodium diet reduces urinary calcium excretion, lowering the risk of calcium-based kidney stones. High fluid intake (>2.5L/day) is also recommended.

Answer 67

A. 0.9% isotonic saline 💡 Rationale: Isotonic saline (0.9% NaCl) is the preferred resuscitation fluid for trauma patients before blood transfusion. Hypotonic solutions (0.45%, 0.3%, sterile water) worsen hypovolemia.

Answer 68

C. 48-year-old with monoclonal gammopathy from B-cell lymphoma 💡 Rationale: Immunotactoid glomerulonephritis is strongly associated with monoclonal gammopathy (B-cell lymphomas, multiple myeloma).

Answer 69

C. Dehydration secondary to diuretic use 💡 Rationale: FeNa <1% suggests prerenal causes (CHF, cirrhosis, hepatorenal syndrome). Diuretics falsely elevate FeNa (>1%) by promoting natriuresis.

Answer 70

A. Calcineurin-inhibitor nephrotoxicity 💡 Rationale: Chronic calcineurin inhibitor (CNI) nephrotoxicity (tacrolimus, cyclosporine) causes tubulointerstitial disease with "striped fibrosis" on biopsy. 🚀 Exam Must-Know Mnemonic 🔹 "AIN = Inflammation, CTD = Fibrosis!" 🔹 "Eosinophils = Drug-Induced AIN!" 🔹 "Striped fibrosis = CNI nephrotoxicity (CTD)!" 🔹 "Papillary necrosis = NSAIDs or Sickle Cell!"

Answer 71

D. Thrombocytosis 💡 Rationale: The TTP pentad includes: Thrombocytopenia (low platelets) Microangiopathic hemolytic anemia (MAHA) Neurologic abnormalities (confusion, seizures) Fever Renal dysfunction 🔹 Thrombocytosis (high platelets) is NOT a feature of TTP.

Answer 72

B. Potassium (K) and Sodium (Na) 💡 Rationale: Intracellular cation: Potassium (K⁺) is the major cation inside cells. Extracellular cation: Sodium (Na⁺) is the main cation in extracellular fluid (ECF).

Answer 73

C. Interstitial fluid 💡 Rationale: Extracellular fluid (ECF) is divided into: Interstitial fluid (~80%) Plasma (~20%)

Answer 74

A. Chloride 💡 Rationale: Chloride (Cl⁻) is the most abundant extracellular anion, playing a key role in acid-base balance and osmolality.

Answer 75

C. 66% 💡 Rationale: Total body water (TBW) is ~60% of body weight. Intracellular fluid (ICF) makes up ~2/3 (~66%) of TBW. Extracellular fluid (ECF) makes up ~1/3 (~33%) of TBW.

Answer 76

C. 0.45% NSS 💡 Rationale: Post-obstructive diuresis can lead to dehydration and electrolyte imbalances. Hypotonic fluids (0.45% NSS) replace free water while preventing hypernatremia. Isotonic fluids (0.9% NSS) may worsen osmotic diuresis.

Answer 77

E. Acidosis responsive to medical therapy 💡 Rationale: Dialysis is initiated when complications of CKD become refractory to medical treatment, including: Uremic symptoms (encephalopathy, pericarditis) Severe hyperkalemia unresponsive to medical therapy GFR <10-14 mL/min/1.73m² Volume overload unresponsive to diuretics 🔹 If metabolic acidosis is controlled medically, dialysis is not immediately needed.

Answer 78

B. 3 weeks 💡 Rationale: If obstruction is relieved within 2 weeks, kidney function can recover. However, after 3 weeks, irreversible kidney damage is more likely.

Answer 79

C. Alport syndrome 💡 Rationale: Alport syndrome is an X-linked or autosomal inherited disorder characterized by: Microscopic hematuria Sensorineural hearing loss Ocular abnormalities (lenticonus, corneal dystrophy) GBM thickening, attenuation, and splitting on biopsy.

Answer 80

A. Peritoneal Equilibrium Test 💡 Rationale: The Peritoneal Equilibrium Test (PET) assesses peritoneal membrane permeability, guiding dialysis prescription adjustments.

Answer 81

C. Amyloidosis 💡 Rationale: Amyloidosis is characterized by: Nephrotic-range proteinuria (>3.5 g/day) Congo red positivity (apple-green birefringence under polarized light) If AA amyloid, kappa, and lambda light chains are negative, it suggests hereditary amyloidosis rather than secondary (AA) or AL (light chain) amyloidosis.

Answer 82

A. Granulomatosis with polyangiitis (Wegener’s) 💡 Rationale: Granulomatosis with polyangiitis (GPA, formerly Wegener’s) is an ANCA-associated small-vessel vasculitis characterized by: PR3-ANCA positivity Crescentic glomerulonephritis (pauci-immune) Upper and lower respiratory tract involvement (sinusitis, epistaxis, hoarseness, hemoptysis) 🔹 Microscopic polyangiitis also causes pauci-immune glomerulonephritis but lacks granulomas and upper respiratory involvement.

Answer 83

A. >3 g/24 hr proteinuria without hematuria 💡 Rationale: Minimal change disease (MCD) is a primary cause of nephrotic syndrome, presenting with: Massive proteinuria (>3.5 g/day) No hematuria Highly steroid-responsive

Answer 84

A. Hypotonic intravenous fluids 💡 Rationale: Hypotonic fluids (e.g., 0.45% saline, D5W) help correct free water deficit in hypernatremia. Hypertonic fluids would worsen hypernatremia. Isotonic fluids are used for volume resuscitation but do not effectively lower Na+.

Answer 85

A. Bilateral tumors 💡 Rationale: Partial nephrectomy is preferred for small renal masses, bilateral tumors, or patients with a single kidney to preserve renal function.

Answer 86

A. Targeting a urine pH less than 5.5 💡 Rationale: Uric acid stones form in acidic urine (pH <5.5). Urinary alkalinization (target pH >6.5) with potassium citrate helps dissolve uric acid stones. Urine pH clues: pH < 5.5 → Uric acid stones pH > 7.5 → Struvite stones (UTI-related) pH ≥ 6.5 → Calcium phosphate stones

Answer 87

A. Treatment typically involves treating the underlying disease 💡 Rationale: MCD is a primary glomerular disease, usually idiopathic, and does not require treatment of an "underlying disease." First-line treatment: Corticosteroids (highly responsive).

Answer 88

A. Eosinophiluria 💡 Rationale: Renal vein thrombosis (RVT) presents with: Flank pain Hematuria Acute kidney injury (rapid decline in renal function) Nephrotic-range proteinuria 🔹 Eosinophiluria is more characteristic of acute interstitial nephritis, not RVT.

Answer 89

A. Calcium oxalate 💡 Rationale: Calcium oxalate stones account for ~75% of all kidney stones and are associated with: Hypercalciuria, hyperoxaluria, and hypocitraturia Radiopacity (visible on X-ray and CT scan)

Answer 90

C. Consider glomerulonephritis 💡 Rationale: Microscopic hematuria with RBC casts and mild proteinuria suggests a glomerular etiology. Further workup should include: Serologic tests (ANA, ANCA, anti-GBM, complement levels) Renal biopsy if necessary

Answer 91

C. Hyperlipidemia 💡 Rationale: Nephritic syndrome presents with: Hematuria with RBC casts Proteinuria (1-2 g/24 hr, not in nephrotic range) Hypertension and edema 🔹 Hyperlipidemia is a feature of nephrotic syndrome, not nephritic syndrome.

Answer 92

D. Periodic acid-Schiff (PAS) 💡 Rationale: PAS stain highlights mesangial matrix expansion and hypercellularity, useful for diagnosing glomerulonephritis.

Answer 93

E. Class V (Membranous Lupus Nephritis) 💡 High-Yield Rationale: Class V lupus nephritis (Membranous LN) is characterized by: Thickened glomerular basement membranes Subepithelial and subendothelial immune deposits Focal endocapillary proliferation Mild mesangial expansion Nephrotic syndrome features (heavy proteinuria, hypoalbuminemia, edema, hyperlipidemia) 🔹 Key Differentiation: Class III (Focal LN) & Class IV (Diffuse LN) → More active inflammation with significant proliferative changes Class V (Membranous LN) → Predominantly basement membrane thickening rather than extensive cellular proliferation. 🚀 Takeaway: Class V lupus nephritis is the only one with prominent basement membrane thickening and subepithelial deposits, mimicking primary membranous nephropathy.

Answer 94

D. HELLP syndrome (Hemolysis, Elevated Liver enzymes, and Low Platelets) Explanation: This patient presents with hypertension, headache, blurred vision, right upper quadrant pain, moderate edema, and hyperreflexia (3+ deep tendon reflexes) at 31 weeks of gestation. Her laboratory values are also significantly abnormal: Severe thrombocytopenia (Platelets = 42,000/mm³) Elevated liver enzymes (AST = 1300 U/L, ALT = 370 U/L) Hemolysis indicator (LDH = 2000 U/L) These findings strongly suggest HELLP syndrome, which is a severe form of preeclampsia with liver involvement.

Answer 95

B. High calcium diet 💡 Rationale: A high calcium diet actually helps prevent calcium oxalate stones by binding dietary oxalate in the gut and reducing oxalate absorption. Risk factors for nephrolithiasis include: Low fluid intake → Increases urine concentration High animal protein intake → Increases uric acid High doses of Vitamin C → Increases oxalate production

Answer 96

D. Factor X deficiency 💡 Rationale: Atypical HUS (aHUS) is complement-mediated and can be congenital or acquired. It is associated with low C3 and normal C4 levels, due to unregulated alternative complement pathway activation. Factor X deficiency is not related to aHUS; Factor H deficiency is more relevant.

Answer 97

c. uric acid

Answer 98

B. Jones-methenamine silver 💡 Rationale: Jones methenamine silver (JMS) stain is useful in highlighting the basement membrane and is commonly used for detecting glomerular sclerosis (hypocellularity). H&E and PAS stains are more useful for cellular changes.

Answer 99

C. Ischemic acute tubular necrosis (ATN) 💡 Rationale: ATN is the most common cause of intrinsic acute kidney injury (AKI), often due to ischemia or nephrotoxins. Hallmark features include acute kidney injury (↑ creatinine) and hyperkalemia. Seizures can occur due to severe uremia.

Answer 100

C. Iodinated contrast use 💡 Rationale: Contrast-induced nephropathy (CIN) is a common cause of AKI after coronary angiography. Features include a rise in creatinine 24-72 hours after contrast exposure.

Answer 101

B. Duration of the obstruction 💡 Rationale: The longer an obstruction persists, the higher the risk of irreversible renal damage. Recovery is best if the obstruction is relieved within 1-2 weeks.

Answer 102

A. Benign prostatic hyperplasia (BPH) 💡 Rationale: BPH is the most common cause of extrinsic obstruction, especially in older men.

Answer 103

B. Prostate cancer 💡 Rationale: Prostate cancer can cause urinary tract obstruction by compressing the urethra. Bladder and cervical cancer can also cause obstruction but are less common.

Answer 104

A. Monosodium urate crystals 💡 Rationale: Gout results from monosodium urate crystal deposition in joints. Negatively birefringent under polarized light microscopy.

Answer 105

C. Night 💡 Rationale: Gout attacks often occur at night due to lower body temperature and dehydration, leading to crystal precipitation.

Answer 106

C. Aristolochic acid nephropathy 💡 Rationale: Aristolochic acid, found in some Chinese herbal medicines, is nephrotoxic and linked to interstitial fibrosis and urothelial cancer.

Answer 107

C. Lead toxicity 💡 Rationale: Chronic lead exposure can cause tubulointerstitial nephropathy and gout (saturnine gout). Painters and those exposed to old paint are at risk.

Answer 108

B. Idiopathic acute interstitial nephritis (AIN) with delayed recovery 💡 Rationale: Corticosteroids can be used in AIN if renal function does not improve after stopping the offending agent. Lupus nephritis and sarcoidosis-related nephritis typically require other immunosuppressive agents.

Answer 109

C. Anuria 💡 Rationale: TIN typically causes polyuria due to an inability to concentrate urine. Anuria is more common in acute obstructive uropathy or severe acute kidney injury (AKI).

Answer 110

pH: 7.13, PCO₂: 25 mmHg, HCO₃: 9 mEq/L ✅ A. Metabolic acidosis 💡 Rationale: pH <7.35 → Acidosis HCO₃⁻ is low (9 mEq/L) → Primary metabolic acidosis PCO₂ is also low (25 mmHg), indicating respiratory compensation.

Answer 111

A. >3 g/24 hr proteinuria without hematuria 💡 Rationale: Nephrotic syndrome is characterized by massive proteinuria (>3.5 g/day) without hematuria. Minimal change disease is highly steroid-responsive and common in young adults and children.

Answer 112

D. Vancomycin toxicity 💡 Rationale: Vancomycin-induced nephrotoxicity leads to ATN, with granular casts and rising creatinine. Risk factors: Prolonged use, high trough levels (>20 mg/L), and concurrent nephrotoxic drugs.

Answer 113

C. Sorafenib or Sunitinib 💡 Rationale: Metastatic renal cell carcinoma is treated with VEGF inhibitors (e.g., Sunitinib, Sorafenib). Immunotherapy (e.g., IL-2) is used in select cases but is not first-line.

Answer 114

B. IgA nephropathy 💡 Rationale: IgA nephropathy presents with isolated glomerular hematuria (often microscopic) and variable renal function impairment. Proteinuria may be absent or minimal in early stages.

Answer 115

B. IV insulin and glucose 💡 Rationale: Insulin shifts K+ into cells quickly and is the most reliable immediate intervention. Calcium gluconate stabilizes the myocardium but does not lower K+.

Answer 116

C. Chromophobe carcinoma 💡 High-Yield Rationale: **Chromophobe Renal Cell Carcinoma (RCC) originates from the distal tubules/cortical collecting duct. Clear cell RCC and papillary RCC originate from the proximal tubule. Oncocytomas arise from the cortical collecting duct but are benign tumors. 🔹 Key Learning: Chromophobe RCC has a solid/tubular growth pattern and is associated with whole arm losses of chromosomes 1, 2, 6, 10, 13, 17, and 21. It has a better prognosis than clear cell RCC but requires differentiation from oncocytomas. 🚀

Answer 117

C. Sorafenib or Sunitinib 💡 Rationale: Metastatic renal cell carcinoma is treated with VEGF inhibitors (e.g., Sunitinib, Sorafenib). Immunotherapy (e.g., IL-2) is used in select cases but is not first-line.

Answer 118

C. Prostate cancer 💡 Rationale: Prostate cancer can cause obstruction by compressing the prostatic urethra.

Answer 119

C. Decrease in single nephron GFR 💡 Rationale: Post-obstructive diuresis initially leads to transient increases in GFR, but prolonged obstruction leads to nephron injury and decreased function.

Answer 120

A. Plasma osmolality 💡 Rationale: Plasma osmolality determines water movement between compartments and is tightly regulated by ADH.

Answer 121

A. 10 mL of 10% calcium gluconate over 2–3 minutes 💡 Rationale: Calcium gluconate stabilizes cardiac membranes and prevents arrhythmias in hyperkalemia. Insulin/glucose, beta-agonists, and sodium polystyrene sulfonate help lower K+, but calcium gluconate is the first-line intervention in severe hyperkalemia.

Answer 122

C. Ankylosing Spondylitis** **Key Buzzwords & High-Yield Clues:** ✔ **Young male (<40 years old)** ✔ **Morning stiffness >30 minutes, improves with activity** ✔ **Limited lumbar flexion (Modified Schober Test <4 cm)** ✔ **Reduced chest expansion (<1 inch)** ✔ **Bilateral sacroiliitis (early MRI finding)** ✔ **Bamboo spine (late-stage X-ray finding)** ✔ **HLA-B27 positive (90% cases, but not diagnostic)** ✔ **First-line treatment: NSAIDs, TNF inhibitors (if refractory)**

Answer 123

C. Chlamydia trachomatis** Reactive Arthritis (ReA)* **Key Buzzwords & High-Yield Clues:** ✔ **Post-infectious arthritis (after GI or GU infection)** ✔ **"Can't see, can't pee, can't climb a tree" (Triad: Uveitis, Urethritis, Arthritis)** ✔ **Asymmetric oligoarthritis (mainly lower limbs, knee, ankle)** ✔ **Dactylitis ("Sausage digits")** ✔ **Enthesitis (Achilles tendon pain)** ✔ **Keratoderma blennorrhagicum (Hyperkeratotic skin lesions on palms/soles)** ✔ **Circinate balanitis (Painless penile ulcers)** ✔ **HLA-B27 positive in 30-50%** ✔ **Sterile synovial fluid (rule out septic arthritis)** ✔ **First-line treatment: NSAIDs, Treat infection (Azithromycin/Doxycycline for Chlamydia)**

Answer 124

**B. Psoriatic Arthritis** **Key Buzzwords & High-Yield Clues:** ✔ **History of psoriasis (Scaly plaques on extensor surfaces, scalp, nails)** ✔ **DIP joint involvement (Unlike RA, which affects MCP/PIP)** ✔ **Dactylitis ("Sausage digits")** ✔ **Nail pitting, onycholysis (>80% cases)** ✔ **Pencil-in-cup deformity (X-ray)** ✔ **Asymmetric oligoarthritis (Most common pattern)** ✔ **Arthritis mutilans (Severe osteolysis, "telescoping fingers")** ✔ **First-line treatment: NSAIDs → Methotrexate → TNF inhibitors if severe** ---