A 45-year-old Caucasian male with a history of chronic myeloid leukemia for which he is receiving chemotherapy presents to the emergency room with oliguria and colicky left flank pain. His serum creatinine is 3.0 mg/dL and his urine pH is 5.0. You diagnose nephrolithiasis. His kidney stones, however, are not visible on abdominal x-ray. His stone is most likely composed of which of the following?
A 77-year-old man with a history of advanced dementia, hypertension, Parkinson’s disease, and diabetes mellitus type 2 is brought to the hospital from a nursing home after several days of non-bloody diarrhea and vomiting. The patient is evaluated and admitted to the hospital. Physical examination shows a grade 2/6 holosystolic murmur over the left upper sternal border, clear lung sounds, a distended abdomen with normal bowel sounds, a resting tremor, and 2+ edema of the lower extremities up to the ankle. Over the next few hours, the nurse records a total of 21 cc of urine output over the past 5 hours. Which of the following criteria suggest pre-renal failure?
MC cause of nephrotic syndrome in adults:-
Which is the primary organ involved in Goodpasture syndrome?
All the following are feature of polycystic disease of kidneys except:-
Oliguria is defined as:-
In Goodpasture syndrome, which organ is involved apart from the lung?
Hyperkalemia means more than
Which of the following is the earliest finding seen in Diabetic nephropathy?
A 69-year-old man with a history of recurrent pancreatitis treated with corticosteroids now has increasing fatigue for 2 years. He does not drink alcohol and has no evidence of gallbladder disease. On examination, there are no abnormalities. Laboratory studies show his serum creatinine is 5 mg/dL and urea nitrogen is 48 mg/ dL. His serum IgG4 is elevated. Ultrasound imaging shows bilateral hydronephrosis. What is abdominal CT imaging most likely to show in this man?
Explanation: ***Uric acid*** - The patient has **chronic myeloid leukemia (CML)** and is receiving **chemotherapy**, which can cause a rapid turnover of cells, leading to **hyperuricemia** and the formation of uric acid stones. - Uric acid stones are **radiolucent** (not visible on X-ray) and are associated with a **low urine pH** (5.0 in this case). *Cystine* - Cystine stones are caused by a **genetic defect** in amino acid transport, leading to high urinary cystine levels. - While they are also **radiolucent**, there is no clinical information to suggest a genetic predisposition for cystinuria in this patient. *Calcium phosphate* - Calcium phosphate stones are typically **radio-opaque** and usually form in alkaline urine, which contradicts the patient's low urine pH [1]. - They are often associated with conditions like **renal tubular acidosis** or hyperparathyroidism [1]. *Magnesium ammonium phosphate* - These are also known as **struvite stones** and are highly suggestive of **urinary tract infections** with urea-splitting organisms (e.g., *Proteus*) [1]. - They tend to grow large, form **staghorn calculi**, and are **radio-opaque** [1]. *Calcium oxalate* - Calcium oxalate stones are the **most common type** of kidney stone and are **radio-opaque**, making them visible on X-ray. - They are typically associated with conditions causing **hypercalciuria** or hyperoxaluria, which are not explicitly indicated here, and they would be visible on the X-ray.
Explanation: ***Fractional excretion of sodium of 0.5%*** - A **fractional excretion of sodium (FENa)** less than 1% is a hallmark of **pre-renal acute kidney injury (AKI)**, indicating that the kidneys are attempting to conserve sodium and water due to decreased renal perfusion. - In pre-renal failure, the kidneys are structurally intact but functionally impaired due to **hypoperfusion**, leading to increased reabsorption of sodium and water in an effort to restore circulating volume. *Urine/plasma creatinine ratio of 10* - A **urine/plasma creatinine ratio** of less than 15 is observed in **intrinsic renal failure**, not pre-renal failure. - In **pre-renal failure**, the ratio is typically **greater than 20**, reflecting the kidney's ability to concentrate urine. *Urine osmolarity of 280 mOsm/kg* - A **urine osmolarity** of 280 mOsm/kg is close to **plasma osmolarity** and suggests an inability to concentrate urine, which is characteristic of **intrinsic renal failure**, particularly acute tubular necrosis. - In **pre-renal failure**, the kidneys actively reabsorb water, leading to a **high urine osmolarity** (typically >500 mOsm/kg) [1]. *Urine Na of 80 mEq/L* - A **urine sodium** concentration of 80 mEq/L is high and indicates significant sodium excretion, which is typical of **intrinsic renal failure** due to tubular damage. - In **pre-renal failure**, the kidneys conserve sodium, resulting in a **low urine sodium concentration** (typically <20 mEq/L). *Urine/plasma osmolarity ratio of 0.8* - A **urine/plasma osmolarity ratio** of 0.8 indicates that the urine is less concentrated than plasma, suggesting impaired concentrating ability, which is seen in **intrinsic renal failure**. - In **pre-renal failure**, the kidneys actively conserve water, leading to a ratio **greater than 1.5**, indicating highly concentrated urine.
Explanation: **Focal segmental glomerulosclerosis** - **Focal segmental glomerulosclerosis (FSGS)** is the most common cause of **primary nephrotic syndrome in adults**, particularly in African Americans and individuals with HIV or obesity [1]. - It involves **scarring** of some glomeruli (focal) and only parts of affected glomeruli (segmental), leading to **proteinuria** and progression to end-stage renal disease [2]. *Minimal change disease* - While it is the most common cause of **nephrotic syndrome in children**, it accounts for a smaller proportion of adult cases [1]. - Characterized by normal-appearing glomeruli on light microscopy but **effacement of foot processes** on electron microscopy. *Good-pasture syndrome* - This is an **autoimmune disease** causing rapidly progressive glomerulonephritis, often associated with **pulmonary hemorrhage** [3]. - It is a much rarer cause of nephrotic syndrome and is characterized by **anti-GBM antibodies** [3]. *Membranous GN* - It is a common cause of **nephrotic syndrome in adults**, particularly in Caucasians, but **Focal Segmental Glomerulosclerosis (FSGS)** has surpassed it as the overall most common primary cause. - Characterized by thickening of the **glomerular basement membrane** due to immune complex deposition, often detected by **anti-PLA2R antibodies** [2].
Explanation: Kidney - Goodpasture syndrome is an autoimmune disease primarily characterized by the production of antibodies against the alpha-3 chain of type IV collagen in the glomerular basement membrane (GBM) and alveolar basement membrane [1]. - This leads to rapidly progressive glomerulonephritis and pulmonary hemorrhage, making the kidneys and lungs the main affected organs, with the kidneys being the primary and universally involved organ [1]. Adrenals - The adrenal glands are not directly involved in the pathogenesis or primary pathology of Goodpasture syndrome. - Conditions like Addison's disease or Cushing's syndrome affect the adrenals, which are distinct from Goodpasture syndrome. Liver - The liver is not a target organ for the antibodies involved in Goodpasture syndrome. - Diseases like autoimmune hepatitis or primary biliary cholangitis primarily affect the liver. Brain - The brain is not affected by the specific autoantibodies targeting type IV collagen in Goodpasture syndrome. - Neurological conditions such as vasculitis of the central nervous system or multiple sclerosis involve the brain.
Explanation: Polycystic kidney disease (PKD) is an autosomal dominant condition where multiple cysts enlarge slowly, compressing and damaging surrounding kidney tissue [1]. ***Erythrocytosis*** - **Polycystic kidney disease (PKD)** typically leads to **anemia** due to reduced erythropoietin production by the damaged kidneys [2]. - **Erythrocytosis** (an abnormally high red blood cell count) is not a common feature of PKD; it is more often associated with conditions like **renal cell carcinoma** or certain chronic hypoxic states. *Renal failure* - **Progressive cyst growth** in PKD eventually destroys functional kidney tissue, leading to a decline in renal function and often culminating in **end-stage renal disease**, which occurs in about 50% of PKD1 patients [1]. - **Renal failure** is a common and serious complication of PKD, necessitating dialysis or kidney transplantation. *Hematuria* - **Cysts in PKD** can rupture into the collecting system, leading to **gross hematuria** (visible blood in urine) or microscopic hematuria [1]. - Trauma to the flank or infection within a cyst can trigger an episode of **hematuria** [1]. *Hypertension* - **Hypertension** is a very common early manifestation of PKD, often preceding any significant decline in glomerular filtration rate. - It results from activation of the **renin-angiotensin-aldosterone system (RAAS)** due to renal ischemia caused by cyst enlargement [1].
Explanation: ***Less than 400 ml of urine excreted in a day*** - Oliguria is clinically defined as **urine production** of less than **400-500 mL per 24 hours** in adults. - This reduction in urine output is often a critical sign of acute kidney injury or other underlying medical conditions impacting **renal function**. *More than 900 ml of urine excreted in a day* - This volume is within the normal range of **daily urine output** for an adult, which is typically between **800 mL and 2000 mL**. - It does not represent oliguria, which indicates a significantly **decreased urine production**. *Absence of urine production* - The complete absence of urine production is known as **anuria**, which is a more severe condition than oliguria. - Anuria is typically defined as less than **50 mL of urine per 24 hours**. *600 ml to 700 ml of urine excreted in a day* - While this volume is below the typical average, it does not meet the strict clinical definition of oliguria, which is typically set at **less than 400-500 mL/day**. - This range might be considered **borderline decreased** but is not severe enough to be classified as oliguric by most standards.
Explanation: ***Kidney*** - Goodpasture syndrome is an **autoimmune disease** that primarily targets the a3 chain of **type IV collagen**, which is found in the **basement membranes** of both the glomeruli in the kidneys and the alveoli in the lungs. [1] - This leads to rapidly progressive **glomerulonephritis** and **pulmonary hemorrhage**, making the kidney a key organ involved alongside the lungs. [1] *Heart* - The heart is generally **not directly involved** in Goodpasture syndrome. - Cardiac symptoms are typically **secondary** to severe anemia from pulmonary hemorrhage or fluid overload from kidney failure. *Spleen* - The spleen is **not a target organ** for the autoantibodies in Goodpasture syndrome. - While it plays a role in immune responses, it is not directly damaged by the disease process itself. *Liver* - The liver is **not affected** by the autoantibodies in Goodpasture syndrome. - **Type IV collagen**, the autoantigen, is not a significant component of the liver basement membranes.
Explanation: ***5.5 mEq/l*** - **Hyperkalemia** is defined as a serum potassium level greater than **5.5 mEq/L** [1]. - This elevated level can lead to significant cardiac and neurological complications if not promptly addressed. *4.5 mEq/l* - A potassium level of 4.5 mEq/L falls within the normal physiological range for serum potassium, which is typically **3.5 to 5.0 mEq/L** [1]. - Therefore, this value does not indicate hyperkalemia. *10.5 mEq/l* - While 10.5 mEq/L is indeed an elevated potassium level, it represents **severe hyperkalemia**, far exceeding the general threshold for diagnosis. - The definition of hyperkalemia begins at a lower threshold of **5.5 mEq/L** [1]. *7.5 mEq/l* - A potassium level of 7.5 mEq/L indicates **moderate to severe hyperkalemia** and is a critical finding requiring immediate medical intervention [2]. - However, the initial threshold for defining hyperkalemia is **5.5 mEq/L**, making this option too high for the general definition [1].
Explanation: ***Microalbuminuria*** - **Microalbuminuria** is defined as the excretion of 30-300 mg of albumin in urine per 24 hours and is the **earliest detectable sign** of diabetic nephropathy, preceding overt proteinuria [1], [3]. - Early detection allows for interventions to slow the progression of kidney damage, such as **strict glycemic control** and **blood pressure management** with ACE inhibitors or ARBs [3]. *Hematuria* - **Hematuria** (blood in the urine) is not typically an early or primary finding in diabetic nephropathy [2]. - While it can occur in some kidney diseases, it is more characteristic of conditions like **glomerulonephritis** or **urinary tract infections** [4]. *Exudates* - **Exudates** refer to leakage of fluid, protein, or cells into tissues, often associated with inflammation or injury, and are not a measure of kidney function. - It's possible this term is being confused with **retinal exudates** (hard exudates) which are a finding in diabetic retinopathy, but not diabetic nephropathy. *Macroalbuminuria* - **Macroalbuminuria** (or overt proteinuria) is the excretion of more than 300 mg of albumin per 24 hours, indicating more advanced kidney damage. - It is a **later finding** than microalbuminuria in the progression of diabetic nephropathy, signifying established kidney disease [3].
Explanation: ***Retroperitoneal fibrosis*** - The patient's history of **recurrent pancreatitis** treated with corticosteroids, elevated **IgG4**, and bilateral **hydronephrosis** strongly suggest IgG4-related sclerosing disease manifesting as retroperitoneal fibrosis [1]. - Abdominal CT would likely show a **soft tissue mass** encapsulating the great vessels and ureters, leading to ureteral obstruction and hydronephrosis. *Renal cell carcinoma* - While it can cause hydronephrosis if locally advanced, it typically presents as a **renal mass**, and is not associated with elevated IgG4 or recurrent pancreatitis in this manner. - Would not explain the classic features of a systemic **IgG4-related disease** or the symmetrical obstruction implied by bilateral hydronephrosis without a directly obstructing renal tumor. *Nephrolithiasis* - This would present with **renal colic** and typically show **calculi** on imaging, which is not indicated by the patient's symptoms or lab findings. - Bilateral hydronephrosis caused by stones would usually imply multiple or strategically placed stones, and would not be associated with a history of IgG4-related pancreatitis or the systemic features observed. *Polypoid cystitis* - This condition involves inflammation and **polypoid changes** in the bladder, typically causing irritative voiding symptoms or hematuria. - It would not explain the **bilateral hydronephrosis** or the systemic features like elevated IgG4 and recurrent pancreatitis that point to a broader systemic inflammatory process.
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