三聚氰胺污染奶粉致儿童尿路结石的临床观察

Clinical observation of childhood urinary stones induced by melamine tainted formula

目的分析三聚氰胺污染奶粉致儿童尿路结石的临床特点。方法收集和分析49例三聚氰胺污染奶粉致尿路结石患儿的喂养史、主诉、并发症、尿常规、泌尿系B超、肝肾功能及血清电解质等资料结果,并与60名无三聚氰胺污染奶粉接触史的健康儿童进行对比。结果①三聚氰胺污染奶粉致儿童尿路结石的现患率为4.6%,平均月龄为25个月,男∶女性别构成比为1.9∶1。②多数患儿表现为无症状性尿路结石。③病例组尿pH和血清HCO3-浓度显著低于对照组,而血清尿酸、谷丙转氨酶、谷草转氨酶和阴离子间隙却明显增高。④多发性结石见于所有患儿,其中双侧结石11例,单侧结石38例,平均6.5mm。⑤结石大小与三聚氰胺暴露量呈显著正相关,而与暴露时间无关。⑥保守治疗1周,38例患儿结石明显缩小,其中21例患儿痊愈。结论①3岁以下男性幼儿是三聚氰胺污染奶粉致尿路结石的易患人群。②多为无症状性,可伴有血生化指标的紊乱,但很少发生尿检异常和肾功能受累。③B超检查结合三聚氰胺污染奶粉喂养史是诊断结石的重要依据,以多发性小结石(<5mm)多见。④对无尿路梗阻及肾功能受累的患儿应首选保守治疗。⑤短期预后良好,长期预后有待于进一步随访。

Objective To investigate the clinical significance of melamine-linked urinary stones in children exposed to contaminated formula.Methods A total of 1 062 children fed with melamine-contaminated infant formula were screened for urinary stones.60 healthy children without melamine exposure were recruited as a control group.Chief complaints,complications,and history of exposure to contaminated formula were documented.Ultrasonography of the urinary tract system was performed in all 1 062 children.In patients and healthy children,urinalysis,renal function,liver status,and serum electrolytes were determined.Results ① We encountered 49 affected children,at a rate of 4.6% .The affected children ranged in age from 1 month to 96 moths,with a mean of 25 months.32 were male,and 17 were female.② Most affected children were asymptomatic and nonurinary findings.③ Patients with urinary stones exhibited lower urine pH and serum HCO3-than those in the healthy children,whereas for serum UA,ALT,AST,and AG the opposite were observed.④ Multiple stones were noted in all patients.Stones in bilateral and unilateral urinary tract were found in 11（22.4% ） and 38 cases（77.6% ） respectively.The stone diameter ranged from 2 mm to 18 mm,with a median of 6.5 mm.⑤ The increase in stone diameter was accompanied by significant augmented melamine content,however,no correlation existed between stone diameter and duration of exposure.⑥ One week of conservative therapy later,stone diameters of 38 cases were significantly decreased.Among them,urinary stones were discharged completely in 21 cases children.Conclusion ① The male infants who are younger than 3 years have more susceptibility than their opposites.② Most of patients are asymptomatic,with sporadic urinary findings and renal dysfunction.③ Small（ 5 mm in diameter） and multiple stones are noted in the majority of patients examined by ultrasonography.④ Conservative therapy may be first tried in all patients without serious urinary obstruction and renal failure.⑤ The short-term outcome is satisfactory.Further grow-up shall be warranted to evaluate the long-term outcome.