A 30-year-old man presents with nausea and fatigue for 2 weeks. He complains about no other health problem. He is found to have Blood Urea Nitrogen of 172 mg/dL, creatinine of 13 mg/dL, and albumin of 4 mg/dL. His urinalysis reveals 3+ protein (quantified at 400 mg per day) and many RBCs. There is no lower extremity edema.
He is non-oliguric. What is the most likely diagnosis? Can it be ANCA-associated glomerulonephritis or focal segmental glomerulosclerosi or Minimal change disease? How to confirm?
