My son just got his yearly blood work back and I'm trying to understand the test results for celiac. On last year's blood work, his level was 1.0, and the paperwork indicated that less than 4 was negative. This year his result was 5.7, and the paperwork indicated that less than 20 was negative. I'm confused; how could the standards for TTG change so much in just one year? And should I be concerned that he went from 1.0 to 5.7 in one year? Everything I read says less than 4 is negative, not 20. Anyone know anything about this?