Nephrology Practice Questions

Q: A patient with congenital nephrotic syndrome requires which of the following procedures?

Renal biopsy. **Explanation:** **Congenital Nephrotic Syndrome (CNS)** is defined as the onset of nephrotic-range proteinuria, edema, and hypoalbuminemia within the first three months of life. **Why Renal Biopsy is the Correct Answer:** In CNS, a renal biopsy is a critical diagnostic step to differentiate between various underlying etiologies. While the most common cause is the **Finnish type (NPHS1 mutation)**, a biopsy helps rule out other structural or syndromic causes like Diffuse Mesangial Sclerosis (DMS) or secondary causes like congenital syphilis or CMV. Histopathology in the Finnish type typically shows characteristic microcystic dilatation of the proximal tubules. **Analysis of Incorrect Options:** * **Live Attenuated Vaccines:** These are generally **contraindicated** in patients with nephrotic syndrome who are on immunosuppressive therapy or are severely edematous/malnourished due to the risk of disseminated infection. * **High-dose Steroids:** Unlike Minimal Change Disease (MCD) in older children, CNS is **steroid-resistant**. The condition is caused by genetic mutations in podocyte proteins (e.g., Nephrin, Podocin), making steroid therapy ineffective and potentially toxic. * **Low-protein Diet:** Patients with CNS lose massive amounts of albumin in the urine. A low-protein diet would worsen the malnutrition and growth failure. Instead, these infants require a **high-protein, high-calorie diet** to compensate for urinary losses. **High-Yield Clinical Pearls for NEET-PG:** * **Finnish Type (NPHS1):** Most common cause; inherited as autosomal recessive; mutation in the **Nephrin** gene (chromosome 19q13). * **Antenatal Diagnosis:** Elevated **Alpha-fetoprotein (AFP)** levels in amniotic fluid or maternal serum. * **Management:** Definitive treatment is **bilateral nephrectomy** (to stop protein loss) followed by peritoneal dialysis and eventual **renal transplantation**.

Q: After her first urinary tract infection (UTI), a 1-year-old girl has a voiding cystourethrogram with findings shown below. Which of the following is the most appropriate management option?

Low-dose daily antibiotics. ***Low-dose daily antibiotics*** - **Prophylactic antibiotics** are the first-line conservative management for **Grade II-III vesicoureteral reflux (VUR)** in young children to prevent recurrent UTIs and potential **renal scarring**. - This approach allows time for potential **spontaneous resolution** of VUR as the child grows, which commonly occurs in low-to-moderate grade reflux. *Immediate surgical reimplantation of the ureters* - **Ureteral reimplantation** is reserved for **high-grade VUR (Grade IV-V)** or cases with breakthrough infections despite prophylactic antibiotics. - **Grade II-III VUR** often resolves spontaneously with conservative management, making immediate surgery unnecessarily aggressive. *Weekly urinalyses and culture* - **Monitoring alone** without prophylaxis increases the risk of **recurrent UTIs** and potential **renal scarring** in a child with established VUR. - This approach fails to provide **active protection** against ascending infections that VUR predisposes the patient to. *Diet low in protein* - **Protein restriction** is indicated for **chronic kidney disease** with significant **renal impairment**, not for VUR management. - VUR with normal renal function does not require **dietary modifications**, and protein is essential for normal growth in children.

Q: Which of the following is NOT a characteristic of nephrotic syndrome in children?

Low complement levels are typically observed. **Explanation:** The hallmark of **Minimal Change Disease (MCD)**, the most common cause of Nephrotic Syndrome in children, is that it is a **"pauci-immune"** condition. In typical childhood nephrotic syndrome, the complement system is not consumed; therefore, **serum complement levels (C3 and C4) remain normal.** Low complement levels should instead raise suspicion for nephritic conditions like Post-Streptococcal Glomerulonephritis (PSGN), Lupus Nephritis, or Membranoproliferative Glomerulonephritis (MPGN). **Analysis of Options:** * **Option A:** Hypertension is generally **not associated** with pure nephrotic syndrome (MCD). Its presence, along with hematuria, often suggests a "nephritic" component or a different pathology like FSGS. * **Option B:** **Minimal Change Disease** accounts for approximately 80-90% of cases in children under 10 years of age, making it the most common histological subtype in this demographic. * **Option C:** **Massive proteinuria** is the defining feature. In pediatric terms, this is defined as >40 mg/m²/hr or a spot protein:creatinine ratio >2. In adults, the threshold is >3.5 g/24 hours. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of Nephrotic Syndrome (Children):** Minimal Change Disease (MCD). * **Most common cause of Nephrotic Syndrome (Adults):** Membranous Nephropathy (globally) or FSGS (increasingly common). * **MCD Morphology:** Light microscopy is normal; Electron microscopy shows **effacement of podocyte foot processes.** * **Treatment:** Corticosteroids (Prednisolone) are the first-line treatment. * **Indications for Renal Biopsy:** Age 12 years, persistent hypertension, gross hematuria, or **low complement levels.**

Q: A 9-year-old boy presents with decreased urine output, cola-colored urine, and swelling of the face and hands for 2 days. He is hypertensive, has a puffy face, and pitting edema of the lower limbs. He had a history of skin lesions 4 weeks prior. A diagnosis of post-streptococcal glomerulonephritis is made. At what point are C3 levels likely to return to normal?

8 weeks. **Explanation:** **1. Why Option C (8 weeks) is correct:** Post-streptococcal glomerulonephritis (PSGN) is an immune-complex-mediated disease (Type III hypersensitivity). The activation of the **alternative complement pathway** leads to the consumption of C3, resulting in low serum C3 levels in >90% of patients during the acute phase. A hallmark of PSGN is that these levels are **transient**. In a typical case, C3 levels begin to rise after the first week and return to the normal range within **6 to 8 weeks**. If C3 remains low beyond 8–12 weeks, alternative diagnoses like Membranoproliferative Glomerulonephritis (MPGN) or Systemic Lupus Erythematosus (SLE) must be considered. **2. Why other options are incorrect:** * **Options A & B (2 and 4 weeks):** While C3 levels start rising early, they usually remain below the normal reference range during the first month of the illness. * **Option D (6 weeks):** Although some patients may normalize by 6 weeks, **8 weeks** is the standard clinical benchmark used in textbooks (like Nelson Pediatrics) and exams to differentiate PSGN from chronic nephritic conditions. **3. High-Yield Clinical Pearls for NEET-PG:** * **Latent Period:** PSGN occurs 1–3 weeks after pharyngitis and 3–6 weeks after pyoderma (skin lesions). * **Sequence of Recovery:** 1. **Diuresis:** First sign of improvement (usually within 1 week). 2. **C3 Normalization:** Within 8 weeks. 3. **Hematuria:** Can persist for 6 months to 1 year. 4. **Proteinuria:** Usually disappears within 6 months. * **Gold Standard Diagnosis:** Renal biopsy (though rarely needed) shows "lumpy-bumpy" appearance on immunofluorescence and "subepithelial humps" on electron microscopy. * **C4 Levels:** Typically remain **normal** in PSGN (unlike SLE where both C3 and C4 are low).

Question 1

A 28-week preterm male neonate, born via emergency caesarean section, develops grunting, nasal flaring, and subcostal retractions within 30 minutes of birth. Oxygen saturation on room air is 78%. The neonatologist orders an urgent chest X-ray (Image 1). Which of the following is the most appropriate immediate pharmacological intervention?

Accepted Answer

A. Intratracheal natural surfactant (poractant alfa) via endotracheal tube

Answer

B. Intravenous dexamethasone to reduce pulmonary inflammation

Answer

C. Nebulised salbutamol to relieve bronchospasm

Answer

D. Intravenous caffeine citrate to stimulate respiratory drive

Question 2

A patient with congenital nephrotic syndrome requires which of the following procedures?

Accepted Answer

Renal biopsy

Answer

Live attenuated vaccines

Answer

High-dose steroids

Answer

Low-protein diet

Question 3

After her first urinary tract infection (UTI), a 1-year-old girl has a voiding cystourethrogram with findings shown below. Which of the following is the most appropriate management option?

Accepted Answer

Low-dose daily antibiotics

Answer

Immediate surgical reimplantation of the ureters

Answer

Weekly urinalyses and culture

Answer

Diet low in protein

Question 4

Which of the following is NOT a characteristic of nephrotic syndrome in children?

Accepted Answer

Low complement levels are typically observed

Answer

Hypertension is not associated

Answer

Minimal change disease is common in children less than 10 years

Answer

Massive proteinuria is greater than 3.5 grams per 24 hours

Question 5

A 9-year-old boy presents with decreased urine output, cola-colored urine, and swelling of the face and hands for 2 days. He is hypertensive, has a puffy face, and pitting edema of the lower limbs. He had a history of skin lesions 4 weeks prior. A diagnosis of post-streptococcal glomerulonephritis is made. At what point are C3 levels likely to return to normal?

Accepted Answer

8 weeks

Answer

2 weeks

Answer

4 weeks

Answer

6 weeks

Nephrology — MCQs

Nephrology — MCQs

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