My 9-year old keeps having weird lab results

[queenbee53011]

My son sees a Pediatric Gastroenterologist for severe constipation. She ordered blood work for him about 6-months ago. It came back with a slightly elevated tTg IgA (celiac test) as well as elevated Ferritin but a high end normal serum Iron level. The GI decided to retest him in six months before deciding anything. We just got the results of the new blood work. and his tTg IgA is still slightly elevated, but now his Ferritin is normal and his serum Iron is high which is exactly opposite from last time. What would be causing this?