Questions: 65-year-old African American female presents with proteinuria by dipstick. She has some increase in creatinine and a decreased GFR with 24-hour urine creatinine collection. She has greater than 20omg of protein on the same collection. She has had diabetes mellitus type 2 for twenty years and has an HbAic of 8.5% which is not well-controlled. What type of kidney disease is most likely in this patient? A. Obstructive uropathy due to nephrolithiasis B. Diabetic nephropathy C. Beta hemolytic strep B glomerulonephritis D. Acute tubular necrosis

The answer is B: Diabetic nephropathy.

Explanation for each option:

A. Obstructive uropathy due to nephrolithiasis: This condition is caused by kidney stones blocking the urinary tract, leading to obstruction. It typically presents with symptoms like severe flank pain and hematuria, rather than proteinuria and decreased GFR as the primary findings. Therefore, this is unlikely to be the correct diagnosis for this patient.

B. Diabetic nephropathy: This is a common complication of long-standing diabetes mellitus, characterized by proteinuria, increased creatinine, and decreased glomerular filtration rate (GFR). Given the patient's history of type 2 diabetes for twenty years and poorly controlled blood sugar (HbA1c of 8.5%), diabetic nephropathy is the most likely cause of her kidney disease.

C. Beta hemolytic strep B glomerulonephritis: This condition is typically associated with post-infectious glomerulonephritis following a streptococcal infection. It is more common in children and presents with symptoms like hematuria, edema, and hypertension. The patient's presentation and history do not suggest a recent streptococcal infection, making this diagnosis less likely.

D. Acute tubular necrosis: This condition is usually caused by ischemic or nephrotoxic injury to the renal tubules, leading to acute kidney injury. It presents with a rapid increase in creatinine and often oliguria, but not typically with significant proteinuria as seen in this patient.

In summary, the patient's long history of poorly controlled diabetes and the presence of proteinuria and decreased GFR strongly suggest diabetic nephropathy as the most likely type of kidney disease.