Nephrology Practice Questions

Q: Systemic eosinophilia with renal failure is found in all of the following except:

Chronic interstitial nephritis. ### Explanation The presence of **systemic eosinophilia** in the context of renal failure is a significant diagnostic clue pointing toward hypersensitivity, embolic, or vasculitic processes. **Why Chronic Interstitial Nephritis (CIN) is the correct answer:** Chronic Interstitial Nephritis is characterized by progressive interstitial fibrosis and tubular atrophy [2]. Unlike the acute form, the inflammatory infiltrate in CIN is predominantly mononuclear (lymphocytes and macrophages) rather than eosinophilic. Because it is a chronic, scarring process rather than an active hypersensitivity reaction, it is **not** associated with systemic eosinophilia or eosinophiluria. **Analysis of Incorrect Options:** * **Drug-induced Acute Interstitial Nephritis (AIN):** This is a classic Type IV hypersensitivity reaction. Systemic eosinophilia is seen in approximately 30–50% of cases, often accompanied by a skin rash and fever [3]. * **Atherosclerotic Renal Failure (Atheroembolic Disease):** Following vascular procedures, cholesterol crystals can dislodge and cause distal ischemia [1]. This triggers a systemic inflammatory response, and **eosinophilia** is a hallmark laboratory finding in about 60–80% of these patients [1]. * **Polyarteritis Nodosa (PAN):** As a systemic necrotizing vasculitis, PAN (especially when associated with certain triggers or overlapping with eosinophilic granulomatosis with polyangiitis) can present with significant peripheral eosinophilia and multi-organ failure, including the kidneys [3]. **NEET-PG High-Yield Pearls:** 1. **Hansel’s Stain:** The preferred stain to detect eosinophils in urine (more sensitive than Wright’s stain). 2. **Triad of AIN:** Fever, rash, and arthralgia (though all three are present in <10% of patients). 3. **Atheroembolic Clue:** Look for "blue toe syndrome" or livedo reticularis following a cardiac catheterization in a patient with rising creatinine and eosinophilia [1].

Q: A 25-year-old man presents with renal failure. His uncle died of renal failure 3 years ago. On slit lamp examination, keratoconus is present. What is the most likely diagnosis?

Alport syndrome. **Explanation:** The clinical triad of **hereditary renal failure**, a positive **family history**, and specific **ocular abnormalities** (like keratoconus) is classic for **Alport Syndrome** [1]. **1. Why Alport Syndrome is correct:** Alport syndrome is caused by mutations in the genes encoding the **alpha chains of Type IV collagen** (COL4A3, COL4A4, COL4A5) [1]. Since Type IV collagen is a structural component of basement membranes, its defect affects: * **Kidneys:** Leads to progressive glomerulonephritis and renal failure. * **Eyes:** Causes **Anterior Lenticonus** (pathognomonic), **Keratoconus**, and maculopathy. * **Ears:** Results in Sensorineural Hearing Loss (SNHL). The mention of the uncle's death suggests an X-linked dominant inheritance pattern (the most common form), though autosomal forms exist. **2. Why other options are incorrect:** * **ADPCKD:** While it causes renal failure and has a strong family history, it typically presents in the 4th-5th decade and is associated with extra-renal manifestations like hepatic cysts and berry aneurysms, not keratoconus [2]. * **ARPCKD:** Usually presents in infancy or childhood with bilateral flank masses and pulmonary hypoplasia; it is associated with congenital hepatic fibrosis, not ocular defects. * **Denys-Drash Syndrome:** Characterized by the triad of Wilms tumor, pseudohermaphroditism, and early-onset nephropathy. It does not feature a family history of renal failure or keratoconus. **Clinical Pearls for NEET-PG:** * **Pathognomonic Eye Sign:** Anterior Lenticonus (conical protrusion of the lens). * **Electron Microscopy (EM):** Shows a characteristic **"Basket-weave appearance"** due to irregular thinning and thickening of the Glomerular Basement Membrane (GBM) [1]. * **Inheritance:** 80% are X-linked Dominant (mutations in *COL4A5*). * **Rule of thumb:** If a young male has hematuria, hearing loss, and eye signs—think Alport Syndrome.

Q: Which complication following kidney transplantation is caused by Cytomegalovirus (CMV)?

Pyelonephritis. **Explanation:** Cytomegalovirus (CMV) is the most common opportunistic viral infection following solid organ transplantation, typically occurring 1–6 months post-transplant. In the context of kidney transplantation, CMV has a specific tropism for the allograft. **Why Pyelonephritis is correct:** CMV infection in a renal transplant recipient often manifests as **CMV Nephritis** (a form of viral pyelonephritis). The virus causes direct tissue injury to the renal parenchyma, leading to graft dysfunction, fever, and histological changes such as "owl’s eye" intranuclear inclusions. It is a significant cause of morbidity and can predispose the patient to secondary bacterial pyelonephritis or acute rejection. **Analysis of Incorrect Options:** * **A. Parotitis:** While CMV can be isolated from saliva, acute parotitis is more commonly associated with Mumps or bacterial infections (Staph. aureus) in dehydrated post-operative patients. * **B. Cholecystitis:** CMV can cause "Acalculous Cholecystitis" in immunocompromised states, but it is a rare manifestation compared to the high incidence of renal involvement in kidney transplant patients. * **D. Gastrointestinal Necrosis and stricture:** CMV is a common cause of GI ulceration and bleeding (especially in the colon), but frank necrosis and stricture formation are more characteristic of ischemic bowel disease or advanced necrotizing enterocolitis. **High-Yield Pearls for NEET-PG:** * **Timing:** CMV typically appears in the "middle period" (1–6 months) post-transplant. * **Diagnosis:** PCR for CMV DNA is the gold standard for monitoring. * **Prophylaxis/Treatment:** **Valganciclovir** is used for prophylaxis; **Ganciclovir** is the treatment of choice for active infection. * **Biopsy:** Look for "Owl’s eye" inclusion bodies in the renal tubular epithelial cells.

Q: What is the best initial test for determining the stage of renal insufficiency?

Serum creatinine. **Explanation:** **1. Why Serum Creatinine is the Correct Answer:** Serum creatinine is considered the **best initial test** because it is simple, inexpensive, and widely available [1]. In clinical practice, the staging of Chronic Kidney Disease (CKD) is primarily based on the **Estimated Glomerular Filtration Rate (eGFR)**, which is calculated using formulas (like MDRD or CKD-EPI) that rely predominantly on the **serum creatinine** value [1]. It serves as the fundamental baseline biomarker for assessing renal function in an initial workup. **2. Analysis of Incorrect Options:** * **Creatinine Clearance (CrCl):** While more accurate than serum creatinine alone, it requires a cumbersome **24-hour urine collection**, making it impractical as an "initial" test [2]. It is usually reserved for specific scenarios like pregnancy, extremes of body size, or prior to dosing highly toxic drugs. * **Glomerular Filtration Rate (GFR):** This is the "Gold Standard" for determining the *actual* stage of renal insufficiency [2]. However, true GFR measurement requires the infusion of exogenous markers like **Inulin** (the physiological gold standard) or radioisotopes (Iothalamate) [1]. These are complex and expensive, hence not the "initial" test. * **Serum Urea:** This is an unreliable marker for staging because levels are significantly influenced by non-renal factors such as high-protein diet, GI bleed, dehydration, and steroid use. **3. Clinical Pearls for NEET-PG:** * **Gold Standard for GFR:** Inulin clearance [2]. * **Most accurate formula for eGFR:** CKD-EPI (preferred over MDRD) [1]. * **Creatinine Lag:** Serum creatinine may not rise until **50% of nephron function** is lost, making it a late marker in acute settings but the standard for staging chronic insufficiency. * **Cockcroft-Gault Formula:** Used for drug dosing; it incorporates Age, Weight, and Serum Creatinine.

Q: Absent P waves with wide QRS complex indicates serum potassium of what level?

More than 8 meq/L. **Explanation:** Hyperkalemia is a critical electrolyte abnormality that causes progressive changes in cardiac conduction [1]. The ECG manifestations follow a predictable sequence as serum potassium levels rise: 1. **Serum K+ 5.5–6.5 mEq/L:** The earliest sign is the appearance of **Tall, peaked T waves** (narrow base, "tent-shaped") in most leads [1]. 2. **Serum K+ 6.5–8.0 mEq/L:** As levels increase, there is paralysis of the atria [1]. This leads to **prolongation of the PR interval**, flattening/decreased amplitude of the P wave, and eventually **disappearance of the P wave**. Concurrently, the **QRS complex begins to widen** [1]. 3. **Serum K+ >8.0 mEq/L:** At this severe level, the P wave is typically **absent**, and the QRS complex becomes **markedly wide**, eventually merging with the T wave to form a **Sine Wave pattern**. This is a pre-terminal rhythm that can rapidly progress to ventricular fibrillation or asystole. **Analysis of Options:** * **Option A (5.4 mEq/L):** This is near the upper limit of normal; ECG is usually normal or shows very mild T-wave peaking. * **Option B (6.5 mEq/L):** At this level, peaked T waves are prominent, but P waves are usually still present, and QRS widening is just beginning. * **Option D (>10 mEq/L):** While ECG changes would be severe here, the classic threshold for the disappearance of P waves and significant QRS widening in medical literature and exams is >8 mEq/L. **Clinical Pearls for NEET-PG:** * **Treatment Priority:** The first step in managing hyperkalemia with ECG changes is **Intravenous Calcium Gluconate** (to stabilize the cardiac membrane), followed by agents to shift K+ intracellularly (Insulin+Dextrose, Salbutamol). * **Pseudohyperkalemia:** Always rule out hemolysis during blood collection if ECG is normal despite high lab values. * **Hypokalemia:** Look for U waves, flattened T waves, and ST depression.

Q: What is the definitive treatment for hypermagnesemia?

Hemodialysis. **Explanation:** Hypermagnesemia is a rare but potentially life-threatening electrolyte imbalance, typically occurring in patients with advanced chronic kidney disease (CKD) who ingest magnesium-containing medications. **Why Hemodialysis is the Correct Answer:** While initial management involves stopping magnesium intake and promoting excretion, **Hemodialysis** is the **definitive treatment**. Magnesium is primarily an intracellular cation, but its serum levels are effectively reduced by dialysis because the kidneys are the only natural route for significant magnesium clearance. In patients with severe renal failure or those with life-threatening symptoms (e.g., respiratory depression, coma, or cardiac arrhythmias), dialysis is the only way to rapidly and reliably remove the excess magnesium load from the body [2]. **Analysis of Incorrect Options:** * **A. Calcium Gluconate:** This is the **immediate first-line treatment** for symptomatic hypermagnesemia [1]. It acts as a physiological antagonist to magnesium at the neuromuscular junction and cardiac membrane, protecting the heart. However, it does not remove magnesium from the body; it only stabilizes the membrane. * **B. IV Fluids:** Saline diuresis (with or without loop diuretics) can enhance magnesium excretion in patients with **normal renal function**. It is not definitive in the setting of renal failure. * **C. Exchange Resins:** These (like Sodium Polystyrene Sulfonate) are used for hyperkalemia, not hypermagnesemia. There is no specific exchange resin for magnesium. **High-Yield Clinical Pearls for NEET-PG:** * **Early Sign:** Loss of deep tendon reflexes (DTRs) occurs at levels of 4–6 mEq/L. * **Late Signs:** Respiratory paralysis and heart block occur at levels >10 mEq/L. * **Antidote:** 10% Calcium Gluconate (10 mL IV over 10 mins) [1]. * **Classic Scenario:** An elderly patient with CKD taking magnesium-containing antacids or laxatives.

Q: What is the earliest finding in diabetic nephropathy?

Urine albumin > 300 mg/24 hours. **Explanation:** Diabetic Nephropathy (DN) is a progressive microvascular complication of diabetes. The earliest **clinically detectable** sign of DN is an increase in urinary albumin excretion [1]. **1. Why Option D is Correct:** The natural history of DN begins with **Hyperfiltration** (increased GFR), followed by **Microalbuminuria** (30–300 mg/24h) [1], [2]. However, in the context of standard clinical testing and the options provided, the progression to **Macroalbuminuria** (Urine albumin >300 mg/24 hours), also known as "Overt Nephropathy," marks the definitive clinical stage of the disease. It is the first sign that signifies established glomerular damage and a high risk of progression to end-stage renal disease (ESRD). **2. Why Other Options are Incorrect:** * **A. Shrunken kidney:** Unlike most chronic kidney diseases, diabetic nephropathy characteristically presents with **normal-sized or enlarged kidneys** even in advanced stages. * **B. Fibrin caps:** These are hyaline deposits in the glomerular capillaries. While characteristic of DN, they are **histopathological** findings seen on biopsy, not the earliest clinical finding. * **C. Elevated serum creatinine:** This is a **late finding**. Creatinine typically remains within normal limits until the GFR has dropped by nearly 50% [3]. **High-Yield Clinical Pearls for NEET-PG:** * **Earliest Functional Change:** Hyperfiltration (Increased GFR). * **Earliest Pathological Change:** Thickening of the Glomerular Basement Membrane (GBM) [2]. * **Most Specific Pathological Finding:** Kimmelstiel-Wilson (KW) nodules (Nodular glomerulosclerosis) [2]. * **Screening:** Annual screening for microalbuminuria is recommended starting 5 years after diagnosis in Type 1 DM and at the time of diagnosis in Type 2 DM [1]. * **Management:** ACE inhibitors or ARBs are the drugs of choice as they reduce intraglomerular pressure.

Question 1

Which of the following is used for staging of Chronic Kidney Disease (CKD)?

Accepted Answer

Estimated Glomerular Filtration Rate (e-GFR) and albuminuria

Answer

Estimated Glomerular Filtration Rate (e-GFR) and serum creatinine

Answer

Estimated Glomerular Filtration Rate (e-GFR) and serum albumin

Answer

Estimated Glomerular Filtration Rate (e-GFR) and urine output

Question 2

Systemic eosinophilia with renal failure is found in all of the following except:

Accepted Answer

Chronic interstitial nephritis

Answer

Drug-induced interstitial nephritis

Answer

Atherosclerotic renal failure

Answer

Polyarteritis nodosa

Question 3

A 25-year-old man presents with renal failure. His uncle died of renal failure 3 years ago. On slit lamp examination, keratoconus is present. What is the most likely diagnosis?

Accepted Answer

Alport syndrome

Answer

Autosomal Dominant Polycystic Kidney Disease (ADPCKD)

Answer

Autosomal Recessive Polycystic Kidney Disease (ARPCKD)

Answer

Denys-Drash syndrome

Question 4

Which complication following kidney transplantation is caused by Cytomegalovirus (CMV)?

Accepted Answer

Pyelonephritis

Answer

Parotitis

Answer

Cholecystitis

Answer

Gastrointestinal Necrosis and stricture

Question 5

T.T.K.G >8 is seen in all except?

Accepted Answer

Cushing syndrome

Answer

Diabetes mellitus

Answer

Acute glomerulonephritis

Answer

Adrenocortical insufficiency

Question 6

What is the best initial test for determining the stage of renal insufficiency?

Accepted Answer

Serum creatinine

Answer

Creatinine clearance

Answer

Glomerular filtration rate

Answer

Serum urea

Question 7

Absent P waves with wide QRS complex indicates serum potassium of what level?

Accepted Answer

More than 8 meq/L

Answer

5.4 meq/L

Answer

6.5 meq/L

Answer

More than 10 meq/L

Question 8

What is the definitive treatment for hypermagnesemia?

Accepted Answer

Hemodialysis

Answer

Calcium gluconate

Answer

IV fluids

Answer

Exchange resins

Question 9

Which of the following conditions is characterized by a normal kidney size?

Accepted Answer

Medullary sponge kidney

Answer

Nephronophthisis

Answer

Autosomal dominant polycystic kidney disease (ADPCKD)

Answer

Acquired renal cysts

Question 10

What is the earliest finding in diabetic nephropathy?

Accepted Answer

Urine albumin > 300 mg/24 hours

Answer

Shrunken kidney

Answer

Fibrin caps

Answer

Elevated serum creatinine

Nephrology — MCQs

Nephrology — MCQs

On this page

Practice by Chapter

Want unlimited practice?