Glomerulonephritis — Nephritic

A 28-year-old man presents with sudden onset hematuria, hypertension (160/100 mmHg), and mild edema 10 days after a sore throat. Serum creatinine is 1.2 mg/dL. Urinalysis shows RBC casts and dysmorphic RBCs. Which investigation is most specific for confirming the diagnosis of post-streptococcal glomerulonephritis?

Which of the following is the hallmark immunofluorescence pattern in post-streptococcal glomerulonephritis (PSGN)?

A 28-year-old man presents with sudden-onset hematuria, mild hypertension (148/92 mmHg), and mild proteinuria (0.8 g/day). Serum creatinine is 1.2 mg/dL. Serologies show elevated anti-streptolysin O (ASO) titre and low C3 levels. Kidney biopsy reveals endocapillary proliferation with subepithelial 'humps' on electron microscopy. What is the drug of choice for induction therapy in this patient?

In a large renal pathology series from a tertiary centre in India, which is the most common site of immune complex deposition in post-streptococcal glomerulonephritis on immunofluorescence microscopy?

A 32-year-old woman from Tamil Nadu presents with a 3-day history of haematuria, mild proteinuria (1.2 g/day), and hypertension (BP 155/95 mmHg). Serum creatinine is 2.1 mg/dL. Urinalysis shows dysmorphic RBCs and RBC casts. Serological workup reveals positive ANCA (cytoplasmic pattern, anti-PR3 antibody). Complement levels (C3, C4) are normal. Chest X-ray shows bilateral pulmonary infiltrates. What is the most likely diagnosis?