A 28-year-old man from rural India presents with gross haematuria, mild oedema, and hypertension (BP 148/92 mmHg) 10 days after a throat infection. Serum creatinine is 1.2 mg/dL, and urinalysis shows RBC casts and proteinuria (1.5 g/day). Complement levels (C3 and C4) are normal. Renal ultrasound is normal. What is the most appropriate next step in management?

Explanation

## Clinical Presentation Analysis This patient presents with classic features of **post-streptococcal glomerulonephritis (PSGN)**: - Recent pharyngitis (10 days prior) - Nephritic syndrome (haematuria, RBC casts, hypertension, mild oedema) - Normal complement levels (C3, C4) — important clue ruling out other GN types - Mild renal impairment (Cr 1.2) - Normal renal ultrasound ## Management Strategy for PSGN **Key Point:** PSGN is typically **self-limited** and managed conservatively in most cases. The prognosis is excellent in children and generally good in adults. **High-Yield:** The cornerstone of PSGN management is **supportive care**, not immunosuppression. Most patients recover spontaneously within 4–12 weeks. ### Supportive Care Components 1. **Salt restriction** — reduces volume overload and hypertension 2. **Antihypertensives** — control BP (ACE inhibitors or ARBs preferred for renal protection) 3. **Diuretics** — if oedema or pulmonary congestion present 4. **Close monitoring** — weekly urinalysis and serum creatinine to track recovery 5. **Dietary protein** — modest restriction if Cr significantly elevated ## Why NOT Other Options? **Renal biopsy** is NOT indicated at presentation in suspected PSGN with: - Clinical diagnosis supported by post-infectious history - Normal complement levels - Stable renal function - No atypical features (e.g., rapid decline, absence of haematuria) Biopsy is reserved for: - Diagnostic uncertainty - Rapidly progressive renal failure - Absence of haematuria (atypical presentation) - No improvement after 3 months **Corticosteroids and immunosuppression** are NOT first-line because: - PSGN resolves spontaneously in >95% of adults - No evidence of benefit from steroids in uncomplicated PSGN - Reserved for rare complications (crescentic disease, severe renal failure) ## Clinical Pearl The **normal C3 level** is reassuring and virtually excludes membranoproliferative GN and lupus nephritis, which present with C3 depression. This finding strongly supports PSGN and argues against aggressive immunosuppression. ## Monitoring Endpoints - Haematuria typically resolves within 3–6 weeks - Proteinuria may persist longer (up to 6 months) - Hypertension usually normalizes with salt restriction and diuretics - Serum creatinine should return to baseline