BACKGROUND: Post-streptococcal acute glomerular nephritis (PSAGN) is mostly a benign condition. The usual sequelae of PSAGN include hypertension, its complications, and acute kidney injury. Severe PSAGN is associated with significant long-term morbidity, and histological abnormalities such as crescentic glomerulonephritis are infrequently reported. PSAGN has also been linked to late-onset chronic kidney disease in some populations due to high levels of proteinuria. AIM: To evaluate the association between proteinuria levels and renal outcomes in children with PSAGN. METHODS: This prospective observational study was conducted at Lady Ridgeway Hospital (Colombo, Sri Lanka) over 15 months. Children with PSAGN were enrolled based on clinical and laboratory criteria. Persistent proteinuria ≥ 2+ for 2 weeks and serum creatinine >
100 μmol/L warranted renal biopsy, assessed RESULTS: Forty-four patients were recruited. There were 27 (61.4%) male patients and 17 (38.6%) female patients. Thirty-seven (84%) of them were above 5 years of age. Twenty (45%) patients had a history of skin sepsis, and eighteen (41%) had a history of throat infection. Among patients with proteinuria ≥ 2+, 53% had serum creatinine >
100 µmol/L, while among those with proteinuria <
2+, 7% had serum creatinine >
100 µmol/L. The association of high-degree proteinuria with elevated serum creatinine was significant ( CONCLUSION: High-degree proteinuria was significantly associated with elevated serum creatinine (>
100 μmol/L) in children with PSAGN. The majority of children with persistent proteinuria ≥ 2+ for more than 2 weeks and the highest recorded serum creatinine >
100 μmol/L had atypical renal histological findings.