The characteristics of immune system changes in children who ingested melamine-contaminated powdered formula in China.

Since 2008, the food safety issue of melamine poisoning has again become a health scare for children. The mechanism of how melamine initiates kidney stones and kidney-associated renal complications is still unknown. Some children who ingested melamine-contaminated powdered formula had leukocyturia, but none had typical symptoms of urinary tract infection. We believed that the children's immune systems might have some changes. We followed up 170 children who ingested melamine-contaminated powdered formula and tested their blood and urine and to observe their immune state, and also performed ultrasonography. In the immune responses of children with stones, immunoglobulin M takes a major immune response and the level of CD3(+), CD4(+) decreased compared with children without stones. There was no difference in complete blood count between the children with stones and those without stones. We concluded that leukocyturia had a certain relationship with non-urinary tract infectious renal disease and these children are susceptible to infectious diseases.