One-year Follow Up of Melamine-associated Renal Stones in Sichuan and Hong Kong

Background: An outbreak of melamine-associated renal stones occurred in mainland China in 2008, which led to large scale community screening of renal stones in Hong Kong. We hypothesised Hong Kong children screened positive did not suffer from melamine-associated renal stones. Methods: This one-year follow-up study compared the clinical features, renal ultrasound findings, and urinary interleukin 8 (IL-8) and monocyte chemoattractant protein 1 (MCP-1) to urinary creatinine ratios between 44 Sichuan children admitted to hospital for melamine-associated renal stones and 22 Hong Kong children screened positive with renal stones. Results: The mean age (±SD) in months of the Sichuan children (25.7±23.8) was significantly lower than that of Hong Kong children (75.0±42.1, p<0.0001). The melamine concentration in the milk consumed by the Sichuan children was significantly higher than that by Hong Kong children. All 44 Sichuan children and only 15 of the 22 Hong Kong children consumed melamine- tainted milk product (MTMP). All except one of the 15 Hong Kong children had their daily melamine